The Pioneers of Hybrid Corn in Canada

This is a revision of a column printed originally in Ontario Farmer in 2004. It’s reposted here with permission. The original column was a sequel to another one describing origins of hybrid corn in all of North America. It has been re-written and is located at https://tdaynard.com/2019/10/25/a-brief-history-of-the-hybrid-corn-industry/ . This column contains the names of more people than is my norm but I feel it important that these individuals (mostly corn breeders) be recognized.

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The breakthrough discovery in 1919 by researcher Donald Jones in Connecticut on how to use double-cross corn hybrids led immediately to the establishment of many public corn inbreeding programs across North America.  One of these was at the newly renamed Dominion Experimental Station at Harrow, Ontario (created originally in 1909 as the ‘Tobacco Station’) where A.E. Mathews from the Central Experimental Farm, Canada Department of Agriculture, Ottawa began corn inbreeding in 1923.  When Mathews died soon afterwards, the work was continued by Dr. Fred Dimmock who spent his summers breeding corn at Harrow while returning to his home base in Ottawa in the off seasons.

Unfortunately, the European corn borer also came to Essex County in the early 1920s, after first appearing first near St. Thomas Ontario in 1909 or 1910.

(Note that this is before the first report of corn borer in the United States near Boston Massachusetts in 1917. The arrival in St. Thomas was blamed on a broom factory that imported broom-corn from central or eastern Europe. By comparison, the European corn borer did not arrive in Illinois until about 1939, and in Iowa a year or so later.)

The resulting damage was so severe that grain corn acreage in Essex and Kent Counties declined by 75% from 1922 to 1928. Yield losses were 100% on many farms. The Harrow corn breeding nursery was virtually destroyed during the devastating years of 1926- 1928. All breeding work was then stopped at Harrow and Dimmock shifted his inbreeding program to Ottawa, including what genetic materials remained from the catastrophe at Harrow.

By the early 1930s, the severity of damage caused by the insects had abated somewhat – in part because of a new provincial mandate that all corn stalks be plowed under 100% before winter – and corn acreage slowly recovered.

Hugh Ferguson is said to be the first Canadian farmer to grow a hybrid corn crop, in 1934 at Woodslee, using seed imported from Wisconsin. Interest in hybrids grew rapidly, thanks to their higher yields and stalk strength, even though they were very late in maturity.

Corn breeding resumed at Harrow in 1939 under the supervision of Dr. G.F.H. Buckley and his assistant Glenn Mortimore.  ‘Mort,’ who I knew well, became the corn breeder when Buckley retired in 1958. Although Harrow inbreds and hybrids became important to Canadian farmers in the years to follow, the U.S. was the sole source of hybrid varieties as usage expanded from about 10% of Kent and Essex corn acreage in 1939, to 50% in 1940, to virtually 100% in 1944.

Especially valuable were inbreds and hybrids from the University of Wisconsin breeding program of Dr. Norman Neal.  A New Zealander, Neal arrived in Wisconsin in 1920 wanting to study perennial forages. But fortunately for corn farmers in the northern Corn Belt, he was persuaded to breed corn instead. It was a ‘Wis-bred’ hybrid that Hugh Ferguson first grew.

My classmate and friend, Jim Cooper of Ridgetown, and former corn breeder for T.C. Warwick and Sons at Blenheim, recalls how Dr.  Neal was a regular visitor to Ontario and an advisor to Jim’s breeding program until the 1970s when Norman was more than 70 years old.

Oliver Wilcox grew the first hybrid seed in Ontario at Woodslee in 1938 (42 ½ bu of seed from one acre) using single-cross parents imported from Wisconsin. Wilcox, then a student at the Ontario Agricultural College, credits Professor G.P. McRostie for triggering this initiative. Wilcox later partnered with Tom Pogue and A.B. Reid in creating Essex Hybrids at St. Clair Beach, Ontario, and was killed in World War II.

The success of Wisconsin hybrids led to the creation in 1939 of a system whereby Wisconsin inbreds were self-pollinated to produce more inbred seed at the Harrow station, and single-cross hybrids were then produced by crossing pairs of these inbreds at the Ridgetown Experimental Farm. The resulting single-cross seed was then turned over to selected seed corn growers to produce double-cross hybrid seed for sale to farmers.  Initially called ‘Wisconsin’ hybrids, these they were renamed ‘Canada’ hybrids in 1940.  For example, ‘Wisconsin 606’ became ‘Canada 606.’  The Harrow-Ridgetown program produced more than 50% of Canadian hybrid corn seed planted by 1947, but was discontinued in 1953 because of the then market dominance by privately produced/owned corn hybrids.

Some well-known seedsmen growing ‘Canada’ hybrids were Ian Maynard and Nap King in Kent County – and Adrien Tellier and the three founders of Essex Hybrids in Essex County.  There were another 10-15 smaller producers/dealers of ‘Canada’ hybrids during the 1940s.

Private hybrids were also popular from near the beginning.  Jim Jubenville began growing Pioneer hybrid corn on his Tilbury farm in the late 1930s.  In 1940, he secured Pioneer’s Canadian marketing rights and began producing hybrid seed.  Pioneer later bought the business back from Jubenville, and moved it to Chatham. The DeKalb Agricultural Association of Illinois established a Canadian company at Tilbury in 1941 (moved to Chatham three years later). Jim Grant at Cottam first produced Wisconsin hybrid seed in 1939 and, in 1942, began growing/marketing hybrids supplied by Funk Brothers in Illinois. Essex Hybrids began producing Pfister Associated Growers (PAG) hybrid seed in 1946.  Many other Canadian corn seed companies arose in the years to follow.

In 1946, Nap King at Pain Court produced the first Canadian-bred hybrid, ‘Harvic 300,’ developed using two Harrow inbreds and two U.S. inbreds. Nap renamed it ‘K300’ as one of his ‘Golden Seal Hybrids.’ Other Harvic hybrids were also marketed under other commercial names.  ‘Harvic’ came from ‘Harrow’ and ‘Victory’ (a reference to World War II). Nap subsequently developed a seed production and marketing arrangement with Pride Seeds in Wisconsin in 1950.

The hybrid, ‘Pride 5,’ introduced in 1958, and promoted actively by Professor George Jones at the Ontario Agricultural College, was the first widely grown hybrid corn in many sub-2900 corn-heat-unit regions of Ontario during the early-to-mid 1960s.

During the early hybrid era, all grain corn (known then as ‘husking corn’) was harvested on the ear and stored and dried naturally in cribs.  But because the germination percentage of crib-managed corn was too low for hybrid seed corn production, artificial drying was needed.  Before 1939 there were only two artificial corn dryers in Ontario – one at Walkerville near Windsor, used to dry corn for distilling, and a seed corn dryer at the Harrow station (followed soon by one at Ridgetown).

Doug Bailey at Chatham, who began working for Jim Grant in 1952, recalled Jim’s story of how, in 1939, he converted a small pig barn into a seed corn dryer, complete with movable barriers to reverse the air flow periodically to ensure even drying.  The fan was run by a tractor and the burner fuel was coal.  Doug managed the dryer at night, while bagging the dried, shelled corn kernels.  Seed was later graded and sized, and then rebagged for retail during the winter.

Nap King’s first seed corn dryer was a double corn crib with a central blower and a coal-fired burner.  When it burned in 1947 (along with most of his other seed-business buildings at Pain Court) he built a second dryer of similar design.  Similar coal or wood-fired dryers were common for other early seed producers.

Dr. Lorne Donovan succeeded Fred Dimmock at Ottawa in 1961.  Collectively, they produced many early-maturing inbreds.  Several companies used these to produce the superior hybrids which triggered a rapid expansion in Ontario grain corn acreage during the 1960s and 1970s.  ‘United 108,’ an important early hybrid, was a single cross between two Ottawa inbreds.

Dr. R.I. (Bob) Hamilton – who had been breeding corn before then at the Agriculture Canada research station at Brandon, Manitoba – succeeded Donovan at Ottawa in 1983, followed by Dr. Lana Reid in 1998.  This breeding program continues today. Serious corn inbred development was initiated at the Ontario Agricultural College by Dr. Ed Gamble in 1956.  Dr. Lyn Kannenberg and Dr. Bruce Hunter assumed the responsibilities in the late 1960s, followed by Dr. Elizabeth Lee in 1998. Liz located her breeding nursery on our farm near Guelph for about 19 years.

The first public corn breeding program in Canada was started by Dr.  L.S. Klink at Macdonald College (now part of McGill University) in Quebec in 1907. The first ‘hybrids’ from Macdonald were actually varietal hybrids (crosses between open-pollinated varieties) and these enjoyed some success grown for silage in Eastern Ontario and Western Quebec.

The earliest-maturing corn variety in the world, Gaspé Flint that has only eight primary leaves, was discovered growing in Quebec by Dr. R.I. (Bob) Brawn, a corn breeder who came to Macdonald after Dr. Klink.

Valuable corn inbreeding programs followed both there and at the University of Manitoba and the Agriculture Canada station at Morden, Manitoba. Dr. W.A. (Bill) Russell, renown for his accomplishments as a corn breeder at Iowa State University, was raised in Manitoba and began his career as a corn breeder at Morden He succeeded S.B. Helgason who began the corn breeding program there in 1939. Dr. John Giesbrecht followed Russell as the corn breeder at Morden.

Some of the world’s best very-early-maturing inbreds originated at Morden. One Morden inbred was a parent of the legendary early hybrid, Pride 5. The University of Manitoba and Morden programs have since been terminated.

After Glenn Mortimore’s retirement in 1975, corn breeding continued at Harrow under the respective leadership of Dr. Tom Francis, Dr. Domenico Bagnara, and Dr. Dick Buzzell, before being terminated in 1983.

Other Agriculture and Agri-Food Canada were Dr. M.D. MacDonald at Lethbridge Alberta, Dr. M. Hudon and Dr. M.S. Chiang (breeding for corn borer resistance) at St. Jean-sur-Richelieu, Quebec, and Dr. I.S. Ogilvie at L’Assomption, Quebec.

In a table below, I have attempted to list all the individuals who have served as commercial corn breeders in Canada since the introduction of hybrid corn. There are more than 40 names in the table and I am sure that I am missing some. Commercial breeding has dominated Canadian inbred and hybrid development since the 1970s, and the collective contribution of private corn breeders to Canadian agriculture has been huge.

But corn could not have achieved its present stature in Canadian agriculture without public breeding. Because the origin of inbred parents for commercial hybrids is rarely identified, farmers are seldom aware of the importance – both historic and present – of public breeding in corn hybrid development.

Canadians, both food producers and food consumers, have benefited immensely from the efforts of both public and private corn breeders.

Canadian private-sector corn breeders
First Name Last Name Company Year first employed
Ardeshir Ahmadzadeh Hyland (W.G. Thompson) 2007
Ardeshir Ahmadzadeh Dow 2010
Gary Bettman Dekalb 1983
Huey Chang Pfizer Genetics 1970s
Edward (Ed) Coatsworth T.C. Warwick and Sons 1960s
Travis Coleman Pioneer 2014
James (Jim) Cooper T.C. Warwick and Sons 1969
James (Jim) Cooper Pickseed 1976
Michael (Mike) Cramer Allellix 1970s
Michael (Mike) Cramer Limagrain 1970s
Thomas (Tom) Crozier Stewart Seeds 1967
Thomas (Tom) Davidson Cargill 1970s
Adrian de Dreu Syngenta 2000
Adrian de Dreu De Dell 2000s
Edward (Ed) Fonseca Dekalb 1980s
Thomas (Tom) Francis Northrup King 1980
Gustavo Garcia Pioneer 1998
John Giesbrecht Self employed, alliance with KWS 1970s
Ramsis Girgis United Cooperatives of Ontario 1960s
Francis Glenn T.C. Warwick and Sons 1974
Francis Glenn Pfizer Genetics 1977
Francis Glenn Glenn Seeds 1980
Robert Glenn Glenn Seeds 2004
Gustavo Gonzalez-Roelants DeKalb/Monsanto 2003
Ian Grant Allellix, then Pioneer 1970s
Steve Hasak Hyland (W.G. Thompson) 1977
Leon Hendrickx Pioneer 2009
Alejandro Hernandez First Line 1987
Bruce Hunter Ciba-Geigy 1995
Bert Innis Mycogen 1970s
George Jones Stewart Seeds 1971
Charles Knoblauch Maple Leaf Mills (United)-Asgrow 1983
Philip (Phil) Krakar United Cooperatives of Ontario 1970s
Steve Kuzir Pride Seeds (King Grain) 1980s
Srecko (Felix) Lauc Maple Leaf Mills (United)-Asgrow 1970s
Srecko (Felix) Lauc Hyland (W.G. Thompson) 1975
Sresko (Felix) Lauc AgriSeed 1980s
William (Bill) Leask Maple Leaf Mills (United)-Asgrow 1976
Donald (Don) LeDrew Dekalb 1977
Margo Lee Glenn Seeds 2013
Rafael Mateo Monsanto/Bayer (DeKalb) 2006
Wallace (Wally) Migus Dekalb 1985
Jean Marc Montpetit Pioneer 2009
Edward (Ed) Peterson Funk’s 1980s
Jon Popi DeKalb/Monsanto/Bayer 1997
Vladimir (Vlado) Puskaric Pioneer 1983
Frank Scott-Pearse Pride Seeds (King Grain) 1960s
William (Bill) Sieveking Maple Leaf Mills (United) 1960s
Bruce Skillings Ciba-Geigy 1995
Darrel Tremunde Dekalb 1990s
Antoon Van der Reijden Ag Reliant Genetics 2000
Mohan Vatticonda Cargill, then Mycogen, then Dow 1980s
Stipe Vujevic Hyland (W.G. Thompson), then Dow 1999
John (Jack) Watson Pioneer 1969
Shawn Winter Maizex 2005

 

I’ll be most appreciative of notifications of errors and omissions. TerryDaynard@gmail.com .

Sources of information:

Several published sources are listed below. However, much of the content of this column comes from personal interviews with Canadian corn hybrid ‘pioneers’ – many of whom are no longer living. These include: Doug Bailey, Bob Braun, Ed Gamble, George Jones, Nap King (aka Napoléon Roy) and Glenn Mortimore. Thanks also to Byron Beeler, Jim Cooper, John Cowan, Tom Francis, Gustavo Garcia, Francis Glenn, Gustavo Gonzalez-Roelants, Bruce Hunter, Peter Hannam, Paul King/Roy (son of Nap King/Roy), Doug Knight, Bill Leask, Don LeDrew, David Morris, Bob Pryce, Peter Robson, Marty Vermey and Shawn Winter – all very much alive – for their extensive help and historical knowledge provided during the writing of this article.

Giesbtecht, John. 1976. Corn Breeding in Manitoba. Canada Agriculture 21 (4): 22-23.

Keddie, P.D. 1974. The Corn Borer Period, 1923 to 1940. The Effects of an Insect Pest on the Production of Corn for Grain in Southern Ontario. Proceedings of the Entomological Society of Ontario 125: 10-22.

Miller, Win. 1999. For Love of the Land, Biography of Napoleon U. Roy). Published by Roy Investment Ltd.

Pegg, Leonard. 1988. Pulling Tassels. Blenheim Publishers Ltd. This is undoubtedly the best published source of information on the Ontario corn seed industry from about 1900 to 1950.

I am also indebted to Dr. Lana Reid (Ottawa) and Debbie Lockrey-Wessel (Harrow) for providing unpublished copies of the histories of corn breeding in Agriculture and Agri-Food Canada, especially at the Central Experimental Farm (Ottawa) and the research station at Harrow.

Why Do We Grow Yellow Dent Corn?

This column was published originally in the Ontario Farmer in 2004. Reproduced here with permission.

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For large parts of the world – notably Mexico, most countries in Latin America and Africa where corn consumption often dominates human diets – corn kernels are white. But at least 99% of North American grain corn is yellow – indeed, almost always yellow dent corn. It’s also mostly yellow in Europe and Asia. Why is that?

As it turns out, it was not always so. And the reason why that’s now true is largely a fluke of history. Here’s the full story.

From its origins about 7000 years or so in Mexico, corn had diversified dramatically before Columbus’s arrival in the New World. There were at least 300 different corn races (most still existent in local production or ‘gene banks’). Kernels ranged from three millimetres to more than three centimeters across; kernel textures varied from very hard (flint) to very soft (floury), and there was every colour possible – black, brown, purple, red, green, orange, yellow and white – often with several different colours on the same kernel. Hopi Indian corn still grown in Arizona is typically blue.

Strangest of all was/is pod corn where the normally small glumes (farmers often call them ‘red dog’) at the base of kernels are so large that they cover the entire kernel – like the glumes of wheat.  Though once considered a relic of wild corn, we now know it is only an interesting mutant. William Emerson wrote in 1878 “a species of corn has a separate husk for each kernel” because of “the efforts of the plant to resist the coldness of the climate”, a fascinating though incorrect explanation.

Number of ears per plant also varies – from one at virtually every leaf axil with Argentinian pop corn, to only one per plant with modern corn hybrids grown at standard seeding rates. For more info on corn races, see chapter one by William Brown and Major Goodman in Corn and Corn Improvement.

When colonists first reached present-day Canada and the eastern United States, aboriginal farmers mainly grew two races of corn.  In the south was ‘gourdseed’ with soft, white, long, thin, deeply indented kernels in up to 48 kernel rows on relatively short, squatty cobs. In Canada and the northern US was ‘flint’ corn with large, round, hard kernels in eight to twelve rows on long narrow cobs.  Flint kernels were mostly white or yellow but other colours were common.

The chance discovery of an infrequent red-kernelled ear at a husking bee meant a gift of already husked ears from other bee participants in aboriginal times – or a kiss from lad or lass of choice (or a round of whiskey) during colonial days.

There was some aboriginal mixing of corn north and south.  When the Tuscarora Indians moved from the Carolinas to New York State in about 1720 to become the final member of the Six Nations, they brought their soft, white corn.  When they later moved to Ontario in about 1784, the Tuscarora white corn came too.

The first European settlers grew the local native corn, but intermixing occurred as settlers or their descendants moved up and down the Atlantic seaboard, and westward.  Many of the early settlers in southwestern Ontario came from the US and brought corn seed with them. Gourdseed and flint corn were both grown in Essex and Kent counties (the most southwesterly counties in southern Ontario) before 1800.

As the annual selection of ears for next-year’s seed continued – sometimes by plan and sometimes at random – there arose hundreds of corn varieties. Sometimes the same variety was grown under many different names. I’ve read one tale from southwestern Ontario where customers could order several different varieties of seed corn at the store front, but the seed all came from the same barrel or two at the back.

In 1751, botanist Peter Kalm described two main types of corn growing in the Atlantic colonies and Canada – “big corn” (or full-season corn), and early-maturing ‘small’ or ‘three-month corn,’ both with a wide range of colours. But a century or more later, with corn farming well established west of the Allegheny-Appalachian Mountains and expanding further, there were many more names. One of the most fascinating was Mammoth White that produced ears typically more than 13 inches in length and circumference.

Natural cross-pollination between flint and gourdseed plants grown together resulted in offspring plants with corn kernels, which were intermediate in shape and structure between the two parental types.  This became known as dent corn.

There were lots of different varieties in Ontario too. Mr. Iler, an Essex County farmer, reported to the Ontario Agricultural Commission in 1880, “the varieties generally grown are the large yellow and white Gourd Seed, though the yellow and white Flint are also grown.” In the early 1900s, some popular Ontario varieties were Wisconsin 7 (white dent), Bailey (yellow dent), White Cap Yellow Dent (yellow dent with white caps), Golden Glow (yellow dent), Longfellow Flint (yellow), Salzer’s North Dakota (white flint), Silver King (white dent), and Early Leaming (yellow dent).

Nap King of Pain Court, near Chatham Ontario, said that when he started in the corn seed business in 1934, most of these were still popular in Ontario, as was Bloody Butcher, a red dent variety. Yellow dent corn was most common, but white corn was grown for corn flakes and other milled products.

Among the many North American corn varieties, a few proved to have much greater long-term significance.

Isaac Hershey, a Mennonite farmer in Lancaster County, Pennsylvania spent many years blending a late, rough-eared gourdseed-type corn with an early maturing flint.  Natural cross-pollination and selection of desirable ears at harvest for next year’s crop led to the creation of a new yellow dent variety called Lancaster Sure Crop.  It gave consistently good yields, even though known for its rough ears and lack of uniformity.  This variety later became a major source of inbreds.

Robert Reid moved west from Cincinnati to Peoria, Illinois in 1845, and brought with him seeds of a reddish gourdseed variety called Gordon Hopkins originally from Virginia. Because of its more southern origins, this variety matured poorly in its first year at Peoria.  Seed quality was poor and the stand emergence thin in the spring of 1847. So Mr. Reid filled in the gaps in early June with seeds of a short-season flint variety called Little Yellow.  Reid liked the resulting yellow dent ears created by natural cross-pollination between the two original varieties, and the yields were good. His son, James, continued to improve the new blended variety, called Reid’s Yellow Dent.

In 1893, Reid’s Yellow Dent won first prize at the Chicago World’s Fair.  Reid’s variety was subsequently used as the genetic base for many other yellow dent varieties.  These included the widely grown Funk’s Yellow Dent produced by Eugene Funk, founder of Funk’s Seeds at Bloomington, Illinois, perhaps the world’s largest seed corn marketer in the early1900s.

But the greatest push came from P. G. Holden, a Michigan farm boy, who worked briefly for Eugene Funk and was then hired by Henry C. Wallace in 1902 to join Iowa State College. (Wallace’s son, Henry A., later founded the Pioneer Hybrid Corn Company.) Holden crossed Iowa many times in a railcar called the ‘Corn Train’ championing corn improvement and the production of Reid’s Yellow Dent.  His promotion was so effective that Reid’s became the dominant corn in Iowa, just as other varieties derived from Reid’s variety were becoming popular in other Corn-belt states. And because Reid’s corn was yellow dent, most Midwest corn became yellow dent, even though white corn had been just about as popular before then.

Reid’s Yellow Dent became a major source of early corn inbreds for hybrids. Early Midwest corn hybrid breeders learned early that inbreds developed from Reid’s crossed well (good hybrid vigour) with inbreds from Lancaster Sure Crop. The variety Iodent, developed by Iowa State College (now Iowa State University) in the early 1900s from Reid’s Yellow Dent, is still an important original source of corn inbreds. Newer inbreds are mostly earlier maturing, higher yielding, more pest resistant, with better stalks and grain quality, but are still yellow dent.

Hence, ‘corn’ as it is now grown in North American, usually means yellow dent. White corn is grown mostly as only a milling crop. But if Robert Reid or Isaac Lancaster had started with white varieties, or if a white corn variety had won at Chicago, or if Holden had promoted a white corn variety, or if the first successful Midwest inbreds had been white, most North American would likely be white today.

(They’re virtually identical nutritionally. Yellow corn obviously is higher in the yellow-coloured beta-carotene, a precursor of vitamin A. Important as that is in parts of the world where grains dominate human nutrition, it’s largely non-significant in North American diets containing many other sources of beta-carotene.)

Such are the quirks of history.

Some references:

Crabb, Richard. 1992. The Hybrid Corn-Makers, Golden Anniversary edition. West Chicago Publishing Company.

Fussell, Betty. 1992. The Story of Corn. University of New Mexico Press.

Kalm, Peter. 1751. Description of Maize. Translated by M. Oxholm and S. Chase from original in Swedish. Economic Botany 28:105-117, 1974.

Pegg, Leonard. 1988. Pulling Tassels. Blenheim Publishers Ltd.

Wallace, Henry A. and William A. Brown. Corn and its Early Fathers, revised edition. 1988. Iowa State University Press.

A Look at UK and Canadian Stats on Agricultural Greenhouse Gas Emissions

In January 2020 I posted a series of tweets about an announced plan by British farmers to reduce net greenhouse gas emissions to zero by 2040 and also looked at how easy this might be for Canadian agriculture. For the convenience of web searchers looking for this type of information and at a future date, I have reproduced them below – along with some comments added as a result of related Twitter discussion.

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I’m impressed with an initiative announced in 2019 by @NFUtweets to achieve zero net GHG emissions for British agriculture by 2040. https://nfuonline.com/nfu-online/business/regulation/achieving-net-zero-farmings-2040-goal/…. This thread includes some analysis from a Canadian perspective, and an examination of corresponding Canadian data.

The NFU report is based on 2017 UK stats showing total national agricultural GHG emissions of 45.6 Mt CO2 equivalent – or about 10% of the UK total. The agricultural number includes CO2, CH4 and N20 losses from fertilizer usage, livestock, manure and on-farm fuel use, though not from changes in agricultural soil org matter content.

If you include UK agricultural soil CO2 emissions – positive for cropland, negative for grassland – and allow for off-farm agricultural transport, the UK total is slightly larger at 49.8 Mt – perhaps 11% of UK total GHG emissions. The UK data are here, https://theccc.org.uk/publication/net-zero-technical-report/…. See also, https://royalsociety.org/-/media/policy/projects/greenhouse-gas-removal/royal-society-greenhouse-gas-removal-report-2018.pdf…

The NFU plan involves about 9 Mt CO2 equivalent (or 20%) removed by on-farm carbon sequestration and up to 22 MT (~50%) as bioenergy from agriculture with the CO2 emission from bioenergy combustion captured and stored underground. The report also mentions potential longer-term use of biochar.

The NFU’s projected on-farm sequestration may be a stretch given pressures to convert from livestock (perennial forages) to arable agriculture. Also, CO2 capture and storage is a largely-still-to-be-developed technology as of year 2020.

But as the analyses to follow indicate, the Canadian agricultural challenge may be even larger. Canadian GHG emission stats for 2017 (the latest available) are in three on-line volumes, all available at: http://publications.gc.ca/site/eng/9.506002/publication.html… .

Here are links to the Executive Summary and Part 1 containing the main data. (Parts 2 and 3 have more details about calculations.) https://canada.ca/en/environment-climate-change/services/climate-change/greenhouse-gas-emissions/sources-sinks-executive-summary-2019.html… http://publications.gc.ca/collections/collection_2019/eccc/En81-4-2017-1-eng.pdf… .

GHG emissions for Canada totalled 716 Mt CO2 equivalent in 2017, marginally less than the 730 Mt in 2005 but well up from the 602 Mt in 1990. These numbers don’t include CO2 sequestration by agricultural soils and forestry (more on this later).

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Agricultural emissions are about 8.4% of Canadian total according to these graphs.

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But these data don’t include on-farm fuel usage. If you include that, the agricultural total comes to 72 Mt CO2 equivalent, or about 10% of Canadian total. This total is little changed from 2005 but up from 1990.

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Within agriculture, GHG data since 2005 have shown a decrease in GHG emissions from ruminants and manure, but an offsetting increase in N2O emissions from soil linked to more N fertilizer usage.

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This table shows agricultural soil sequestration in Kt/year CO2 equivalent attributable to less summer fallow, more no-tillage, and shifts between annual and perennial crops. (Histosols means organic soils.) Calculations assume that the per-ha/per-year no-till benefit decreases annually from date of implementation.

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This table, prepared using the Canadian data, shows sums of agricultural emissions minus agricultural soil sequestration of carbon. One weakness in the input data is the lack of recognition of the increased soil sequestration with higher yields (eg., with increased fertilization).

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One major conclusion: Canadian agriculture faces a huge challenge if it’s to cut net GHG emissions by 30% below 2005 levels by 2030, as per the Canadian Paris Accord commitment – let alone 100% by 2040 or 2050 (See, https://canada.ca/en/environment-climate-change/services/environmental-indicators/progress-towards-canada-greenhouse-gas-emissions-reduction-target.html…).

Here are some additional comments not in the original Twitter thread:

There is debate about the inclusion of a credit for all of the carbon in organic matter fixed photosynthetically by crop plants. If the fixed carbon is converted to CO2 quite quickly, say within a year or less – as in crop residue left on the surface and not converted to longer-term soil organic matter – or harvested as grain, seed and/or forage and consumed soon after as livestock or human food – this is not included in the calculations as it is assumed to represent neither a longer-term source nor sink.

But what about the carbon in crop products/commodities exported to other countries? The IPCC calculations give no C credit to the exporting country or debit to importer, but maybe they should. Where exports are involved, the IPCC generally assigns GHG emissions associated with manufacturing/production to the country where that occurs, rather than the country where consumption occurs. However, one exception occurs with  petroleum and its energy products where GHG emissions are credited to the country of consumption. That’s why, for example, Canada gets assigned the GHG emissions associated with oil extraction, processing and shipment – but not combustion if/when that occurs in another country.

Another anomaly occurs with biofuels. From one perspective, the grain and oilseeds used to make fuel ethanol and biodiesel are no different that that used to produce food and feed. The CO2 fixed during the growing season is mostly returned to CO2 within a year. But, ethanol and biodiesel used as fuel result in important reductions in net GHG emissions associated with transportation fuel – i.e., by comparison with the hydrocarbons they replace. That credit goes to the transportation fuel manufacturers under IPCC accounting. Should it go to agriculture – as what the UK NFU proposes to address about 50% of their strategy for meeting a zero-emission goal by 2040? It depends on perspective.

One final comment: While discussion such as that in the preceding three paragraphs stimulates active discussion within agricultural circles, ultimate judgments on credits for cuts in net GHG emissions for agriculture will depend on calculation procedures dictated by IPCC. Here’s an index to IPCC calculation protocols. My impression is that it is extremely difficult to effect changes especially if driven by one country and/or one industry. That’s a hurdle that farm groups in many countries will face as they attempt to develop and get credit for strategies to reduce net GHG emission through innovative uses of agricultural products.

A special thanks to farmer Fraser McPhee at Dauphin Manitoba for his commitment to a better understanding of GHG emissions in Canadian agriculture – and for the useful discussion which triggered some of my discussion above. While Fraser and I don’t necessarily agree on everything, I do appreciate his dedicated efforts.

How Early Farmers Grew Corn – Even as Wheat Dominated 19th Century Agriculture

 

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Photo by Reuben Sallows, Goderich Ontario, early 1900s.

This column was published originally in the Ontario Farmer in 2004. Reproduced here with permission.

Early corn in Ontario

Even though it had been the principal crop of aboriginal agriculture for a thousand years, corn played only a minor role in pioneer Ontario. The settlers wanted wheat to make European foods and for export sales.  Spring wheat and, later, winter wheat were planted on the first cleared fields. Water-powered flour mills followed quickly and surplus produce was shipped to Montreal and England.

Only in Essex and Kent Counties in extreme southwestern Ontario was corn grown to a significant extent by immigrant farmers.  While settlers ate some corn-based foods, corn was mainly for pigs and chickens.

Father Louis Hennepin, the first European to describe Niagara Falls, recorded the earliest reference to European agriculture in present-day Ontario – on about 100 acres of land near Fort Frontenac (Kingston) around 1680. “Both the Indian and European corn throve very well,” he wrote, though “the corn was very much spoiled by grasshoppers,” a common result in all the parts of Canada because of “the extreme humidity of that country.”

The first permanent (French) settlers arrived near present-day Windsor in 1749, across the river from Fort Pontchartrain built in 1701 at the present site of Detroit Michigan.  They likely grew corn as did their aboriginal farmer neighbours. More extensive settlement occurred all across Southern Ontario after American independence in 1783.

Corn was grown by “Loyalist” settlers who came to Essex and Kent from the newly formed United States of America after 1783. In 1802, Angus Mackintosh, an Essex agent for the North West Company, informed farmers that he needed more white flint corn, not wheat or yellow “gourd” corn, for northern trading posts. But that was unusual. Wheat was dominant. For many farmers, the crop rotation after clearing forest trees was wheat-wheat-wheat.

Wheat ruled Ontario agriculture until 1865 when the American civil war ended and new US import duties depressed Ontario wheat prices.  Provincial livestock production then flourished. Cheese factories arose everywhere and dairying expanded.  Better-quality cattle were imported and bred.  Wheat was still the main or only grain crop on farms until the early 1900s when production shifted to the Prairies and oats and barley grew in popularity in Ontario. In Kent-Essex, tobacco became the money crop.

The 1881 Report of the Ontario Agricultural Commission devotes 27 pages to wheat, versus four for each of “Indian corn” and oats and barley.  Though grown mainly in southwestern Ontario, small quantities of corn were present elsewhere, including Muskoka and Manitoulin where “Corn does well and is seldom affected by spring frosts,” states the report.

Though the report discusses corn fodder, corn silage is not mentioned.  Nor is it in the extensive “History and Incidents of Indian Corn, and Its Culture” published by William Emerson in the United States in 1878.  But “The Book of Corn” published in 1903 has a full chapter on silage.  Corn silage was apparently produced on a limited scale after 1850, though the first tower silos were only built (in Michigan and Maryland) in 1875. Hand-chopped corn silage was popular in Ontario after 1900 to supplement turnips, carrots and mangolds/mangels grown for winter feed.

Dual-purpose Shorthorn and Ayrshire cattle dominated Ontario livestock in 1881. There were no Ontario Holsteins yet, though present in New York State. There were many sheep – and sheep exports – 100,000 to Britain in 1880 alone.  Pork production was minor except in Kent and Essex where corn was fed. Local corn was sold to distilleries in Walkerville and Amherstburg after 1850.

Early corn in the Thirteen Colonies

Unlike Ontario, corn dominated agriculture in the Thirteen Colonies – for reasons of both circumstance and soil-climate.

The first settlers in Virginia in 1607 lacked skills or interest in farming.  England was to provide the food while they sought natural riches. But the boats didn’t arrive, and kind aboriginals provided corn to prevent them from starving.  Only after two years did settlers learn to grow their own.

The Pilgrims reaching Cape Cod in 1620 expected to buy corn from natives.  Natives soon taught them how to farm. Early settlers elsewhere in the Thirteen Colonies learned native corn farming techniques from the beginning.  Peter Kalm, a Swedish botanist, wrote in 1751 that corn did much better than wheat on the prevalent sandy, drought-susceptible soils of the Atlantic seaboard.  In Pennsylvania and New York where soils are less sandy, wheat was more dominant.

American colonists adapted native farming techniques: they girdled and burned trees; planted corn in hills (versus broadcasting seeding of grain crops in Europe) and stored ears in cribs.  Birds, rodents and weeds plagued colonial crops just as they had for the natives.  However, horses and oxen were now used for tilling soils. Aboriginal farmers had used “no till” planting and hand weeding.

Farmer George Washington reported 12.5 bushels per acre on 75 acres of corn grown in 1800, worth about thirty cents per bushel.  President Thomas Jefferson, also a prominent farmer, wrote about corn growing.

As settlement proceeded westward, corn farmers led the way.  Frontier farmers often grew corn continuously without fertilizer on newly cleared lands.  When infertility depressed yields, they simply moved westward.  Other farmers fertilized corn with manure, fish or crop rotations.

Corn adapted slowly to mechanization

Farming changed little for two centuries after the first arrival of settlers from Europe, but as the nineteenth century unfolded, so did the inventions. There were thousands of new plows and tillage machines. One hundred patents for hand planters before 1869. The first mechanical corn seeders appeared after 1800, but acceptance came slowly. Early mechanical seeders could not plant corn in hills perfectly aligned both ways for cultivation (“horse-hoeing”) for weed control.

Farmers marked fields two ways with light sleds (runners 40-44 inches apart), and then planted three to eight seeds per hill, up to four acres/day, with a “hand jabber” planter. Final stand depended on pest damage. “One seed for the blackbird, one for the crow, one for the cutworm and one to grow.” Tillers (suckers) were often removed manually.

Though testimonial information (formal research began only about 1870) showed that drilled corn yielded more, check planting remained popular – for both ease of cultivation for weed control and aesthetics. I remember seeing check-planted corn in southwestern Ontario and the US into the 1950s.  Fields with corn hills lining up every direction were sure attractive.

Mechanical planting in properly spaced hills did evolve, thanks to the use of trip wires with regularly spaced knots that were laid across fields to be seeded, but these were awkward to use.

Mechanical harvesting came even more slowly. Early settlers, like natives, harvested ears with husks attached in autumn, and “shucked” them later in community husking bees – major social events. Hand-held bone or wooden “shucking pegs” were the same as those used centuries earlier.

By 1800, corn shocks (stooks) had become popular. The farmer first bound together the tops of plants in four adjacent hills, using stalks, grape vines or elm-bark strips, and then stacked plants from other hills around the outside.  Plants then dried, sometimes until well into winter, when ears were removed. Winter wheat was often inter-seeded between the shocks.  Horse-drawn sleds with stalk-cutting edges, and, later, corn binders, speeded the shocking process in the mid-to-late 1800s.

Stover remaining after ear removal was often used for winter feed.  Though leaves were once collected from immature plants, this largely ended before 1825 because it reduced yield.

Direct harvesting and husking became common.  Horses pulled wagons slowly up the field while farmers removed and shucked the ears, and threw them into wagon boxes.  “Bang boards” above the opposite side of the wagon helped prevent ears from being thrown clear across.

Efforts to design a mechanical corn “dehusker” began before 1850. “Indian Corn and its Culture,” published in 1878, describes a “machine husker” resembling a modern corn picker. But the 1903 “Book of Corn” states, “no practical machine adapted to [field harvesting] has appeared.” The first horse-drawn field pickers arrived around 1900.

Nap King of Pain Court, Ontario, formerly president of King Grain, recalled how his father first bought a tractor-powered corn picker in 1927. “Much better than hand picking,” said Nap.  But both picker and tractor were causes for controversy.  Pickers missed too many ears, critics said.  And tractors compacted the fields!

Mechanical corn picking was hampered by the natural breakage of stalks before harvest – far worse when European corn borer insects appeared about 1920.  Indeed, the acceptance of hybrid corn in the 1930s and 1940s in southwestern Ontario was driven as much by superior standability and machine harvestability as by better yields.

Shelling was equally time consuming.  Hand shelling gave way to hand-powered single-ear  shellers by about 1850.  Larger machine shellers came much later.

As late as World War I, except for “horse power,” North American corn farming largely resembled what native farmers had practiced centuries earlier.  Most of what now constitutes “modern corn technology” had yet to be developed.

Some references:

Fussell, Betty. 1992. The Story of Corn. University of New Mexico Press.

Hamil, Fred C. 1951. The Valley of the Lower Thames, 1640-1850. University of Toronto Press.

Kalm, Peter. 1751. Description of Maize. Translated by M. Oxholm and S. Chase from original in Swedish. Economic Botany 28:105-117, 1974.

Orange Judd Company. 1903. The Book of Corn.

Pegg, Leonard. 1988. Pulling Tassels, A history of seed corn in Ontario. Blenheim (ON) Publishers Ltd.

Reaman, G. Elmore. 1970. A History of Agriculture in Ontario. Volume I. Hazell Watson & Viney Ltd., Aylesbury UK.

 

How Corn Began

 About 17 years ago, I wrote a series of articles on the history of corn for the Ontario Farmer. With its permission, I plan to reproduce several of them, with minor revision, on this blog site. A couple of the original columns feature historical information already available on the site and so won’t be reproduced here. Future columns will be mainly about corn in Ontario and adjacent parts of North America in years following settlement by immigrant farmers. However, the first is a brief overview of corn’s origins. More information is available in the references listed at the end of the article.

Maize-teosinte

Teosinte ear (Zea mays ssp mexicana) on the left, maize ear on the right, and ear of their F1 hybrid in the center (photo by John Doebley, University of Wisconsin)

The real gold discovered by Columbus in 1492 in the New World was a plant that Caribbean Indians called “Mahiz.” Maize seeds were brought back to Spain, planted and the new crop spread quickly.  Within a generation, it covered much of southern Europe and parts of Africa.  Soon after, it reached India, China and Southeast Asia.

The high, yield and ability of maize/corn to produce several hundred seeds per seed planted – far greater than with Old World grains – made it popular.

Corn flourished, though details were rarely recorded.  Indeed, seventeenth-century botanists identified Turkey or Africa as its place of origin. “Turkish wheat” or “Guinea wheat” were common names. Some writers linked corn to Biblical scriptures, proclaiming a Mediterranean origin.

A treasured book of mine, “Le Maïs ou Blé de Turquie,” first published in Bordeaux France in 1785, debates whether the source was Old World or New. With time, the evidence became clearer: It was the New World, specifically Mexico, where corn began.

The story begins with arrival of humans in Mexico sometime before 10,000 BC.  The first people in Mexico, as in most of the Americas, were big game hunters. But as human populations grew and large animals became scarce or extinct (mammoths, indigenous horses), people in Mexico became more dependent on wild plants for food. With time, they selected preferred plant types and eventually learned about planting.

Beans, squash and gourds were among the first “farmed” crops.  They also ate grass seeds such as Setaria (foxtail). Eventually they tried teosinte.

Teosinte is a grassy weed growing in certain semi-arid valleys of Mexico and northern Guatemala.  Teosinte plants exist as both annuals and perennials and look like well-tillered corn, with male flowers at the top and female flowers in leaf axils.

The seed and ear structures, however, are very unlike corn. Seeds are encased in hard shells – a bit like buckwheat – and grow in a single spike that shatters at maturity. There are many spikes per leaf axillary node.

Because of the different seed structure, many scientists rejected teosinte as the parent for corn when this was first proposed sometime before 1900. Some still argue that the true ancestor is a now-extinct plant, and that teosinte is only a relative.

But the case for teosinte is strong.  Corn and teosinte have the same chromosome number, they cross easily, and resulting seeds are fertile.  Genetic studies have shown that the key differences between teosinte and corn involve only about five major genes.

Teosinte seed casings must be removed and/or softened before eating. Some researchers suggest that early diners popped the seeds by heating – like popcorn.  Perhaps seed casings were removed using grinding stones. Or teosinte seeds may have been softened in water and then eaten directly with hulls spit out after partial chewing (like sunflower seeds). Eventually someone found a mutant with no seed cases, or softer ones, and teosinte became a better food crop.

The difference between a single and multiply double kernel rows also involves mutant genes. One gene permitted teosinte kernels to grow in two alternating rows, somewhat like heads of rye or two-row barley.  Other mutations meant two-row teosinte became four-row corn – and later eight-row corn.  The latter is still grown in Mexico, known by names such as “Maiz de Ocho.” (The number of kernel rows is always even since two seeds develop at each node on the compressed “rachis” or cob in all types of corn except teosinte where only one kernel develops.  Modern Ontario hybrids usually have 14, 16, 18 or 20 kernel rows.)

Natural mutation and human selection changed teosinte/corn from having several spikes per axil to only one large ear.  However, the original teosinte trait still exists in modern corn.  If you examine an ear of corn at silking, you’ll find several tiny ears – each with its own minute kernel initials – in the axils of husk leaves.  If the main ear does not pollinate properly, the side ears will sometimes enlarge and produce silks.

The first archeological evidence of corn dates back 7000 years to Tehuacán caves near Mexico City containing cobs, about one inch long, which once bore 50-60 kernels in four or eight kernel rows per ear.  The initial steps in domestication likely occurred as much as 2000 years earlier.

Teosinte still crosses naturally with corn where teosinte grows wild near Mexican cornfields.  Cross pollination occurred regularly during early days of domestication, adding new genes to the corn genetic base.

A rapid expansion in corn ear size occurred about 1500-1000 BC.  Higher yields triggered a boom in human cultural development. Corn served as the base – both nutritional and religious – for several Mexican societies including the successive Olmec, Mayan, Toltec and Aztec civilizations between 1200 BC and the time of Spanish conquest. Corn also dominated life for the Incas in South America.

The first evidence of corn in the United States was found in caves in New Mexico, containing corn ear remnants from about 2500 BC.  Corn was grown extensively from 0 to 1400 AD throughout Arizona and New Mexico using sophisticated irrigation schemes. These major southwestern civilizations ended for unknown reasons about 200-400 years before the Spanish conquest, leaving only the building ruins that are so intriguing to tourists today.  However, some present-day Hopi, Navajo and other southwestern Indian communities still grow corn using traditional varieties. (Blue corn is popular.)

From Mexico and the southwestern United States, corn spread slowly north and east by various avenues including a dominant route along the Gulf coast to the Mississippi and thence north. Substantial settlements existed at various times up the Mississippi.

A spectacular site is the former city of Cahokia, near St. Louis, where up to 30,000 people lived before 1400 AD in a settlement extending over six square miles.  Imagine how much corn would have been required at an estimated per-capita annual consumption of 8.5 bushels!

Most native corn in the Mississippi valley and southeastern United States had soft, long, thin, indented white kernels, commonly called “gourdseed” corn by settlers. Ears were fat and squatty, often containing more than one thousand kernels in 16 to 36 kernel rows.

By contrast, the indigenous corn grown in Ontario, in New England, the northern Great Plains and in states bordering the Great Lakes, had round, yellow or white, flint kernels, generally with only eight or ten kernel rows on long, thin cobs.

U.S. east coast settlers grew both flint corn favoured by northern aboriginals and gourdseed varieties from the south.  Eventually the two were crossed to form the familiar dent corn that now dominates North American agriculture.

The plant now grown worldwide is known as “maiz” in Latin America, “maïs” in France and Germany, “blé d’inde” in Quebec, “maize” in most English-speaking countries and by many other names elsewhere – including “corn” in English-speaking Canada and the United States. The double name, “Indian corn,” once used widely to distinguish maize from old world corns such as wheat and rye is rarely used. (“Indian corn” now means only a particular type of multi-coloured flint.)

Corn has been called the New World’s greatest gift to humankind. Little did Christopher Columbus realize the real treasure he had encountered in the New World was the few corn ears he took back home.

Some readily accessible references on origins of corn:

Carroll, Sean B. 2010. Tracking the Ancestry of Corn Back 9,000 Years. New York Times. https://www.nytimes.com/2010/05/25/science/25creature.html

Doebley, John. 2004. The Genetics of Maize Evolution. Annual Review of Genetics. https://teosinte.wisc.edu/pdfs/DoebleyAnnRev2004.pdf

Edmeades, G.O.; Trevisan, W.; Prasanna, B.M.; Campos, H. 2017. Tropical maize (Zea mays L.). In: Campos, H.; Caligari, P.D.S. (eds). Genetic improvement of tropical crops. https://cgspace.cgiar.org/handle/10568/91727

Fedoroff, Nina. 2004. Ancestors of Science – Prehistoric GM Corn. Science. https://www.sciencemag.org/careers/2004/10/ancestors-science-prehistoric-gm-corn

Katz, Brigit. 2018. Rethinking the Corny History of Maize. Smithsonian Magazine. https://www.smithsonianmag.com/smart-news/rethinking-corny-history-maize-180971038/

National Geographic. 2009. Corn Domesticated From Mexican Wild Grass 8,700 Years Ago. https://blog.nationalgeographic.org/2009/03/23/corn-domesticated-from-mexican-wild-grass-8700-years-ago/

A Brief History of the Hybrid Corn Industry

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(Last revised January 4, 2020)

Corn is the biggest agricultural success story of the Americas, from its beginning as a wild grass 7000 or more years ago in Mexico to become one of three dominant food and feed crops of the modern world. Its emergence as the grain crop with yields that surpass that of all others coincides with the creation of hybrid corn.

Several books have been written detailing the birth and early days of hybrid corn, including Corn and its Early Fathers, by Henry A. Wallace and William L. Brown, and Richard Crabb’s The Hybrid Corn Makers. Both are excellent. These and other references are listed at the end of this article. This article is written to provide a 5300-word (20 minute) overview for those lacking the time to read more.

Corn book photo #2

The Beginnings of Hybrid Corn

Hybrid corn may represent the biggest agricultural miracle of the twentieth century.  In fact, the full story begins back in 1694 when a Dutch botanist, Rudolph Camerarius discovered why corn pollen was needed for seed formation, and in 1716 in Massachusetts when Cotton Mather, a Puritan minister discovered the importance of wind pollination.  Co-mingling of roots had previously been assumed responsible for genetic interactions between adjacent plants.

In the early 1800s, John Lorain, an innovative Pennsylvania farmer and writer, learned that natural cross pollination between southern gourdseed varieties and northern flints produced a new type of corn with intermediate kernel (i.e, “dent”) characteristics and higher yields.

Credit for the first professional interest in hybrid corn generally goes to Professor James Beal, a botanist at the Michigan Agricultural College (now Michigan State University) who, in 1879, crossed two open-pollinated varieties for the sole purpose of increasing yield. Beal got the inspiration from Professor Asa Gray, one of his former professors at Harvard University. Gray, in turn, was a friend of Charles Darwin who had discovered the increased plant vigour that occurs when unrelated corn varieties are crossed. Beal’s initiative was not pursued commercially.

In 1896, Professor Cyril Hopkins at the University of Illinois began ‘ear-to-row’ selection for corn lines that were either high or low in either protein or oil, starting with the common variety, Burr White. In 1900, he hired a recent graduate, Edward M. East, to help with the project. In addition to managing Hopkins’ project, East and a couple of university colleagues began to inbreed corn, starting with another popular variety, Leaming. When East took a position at the Connecticut Experimental Station in 1905, he took the inbreds with him, and in 1907 began yield testing hybrid crosses involving the Leaming inbreds.

Simultaneously and independently, Dr. George Shull began work in 1905 just a few miles away at the Carnegie Institute in Cold Springs Harbor on New York Island. He produced inbreds and hybrid crosses starting with seed of a white dent corn variety that he got from a farm in Kansas. Shull recognized that this could be a means of increasing corn yields and gave talks stating such to American seedsmen in 1908, 1909 and 1910 – talks that were instrumental in triggering related research and commercial development in the US Midwest. However, Shull was a botanist more interested in genetics than agriculture, and he discontinued his research on corn because of bird problems in field plots, switching instead to Evening Primrose, Shepherd’s Purse and other wild species.

Both East and Shull recognized the potential value of hybrid vigour in increasing corn yields, but neither had a realistic plan for allowing farmers to benefit, given the very low seed yields of inbreds then available for use as single-cross hybrid seed parents. East envisioned a scheme based on crosses of open-pollinated varieties or ‘top-cross’ hybrids (pollen from inbreds used to pollinate silks of detasseled open-pollinated varieties) that farmers could do themselves. But no farmers were persuaded to do that. Shull considered his findings to be primarily of academic interest.

Dr. H.K. Hayes began corn inbreeding while he was an assistant to Dr. East at the Connecticut station and also a graduate student at Harvard University where East was a faculty member. Upon graduation, Hayes took a position at the University of Minnesota in 1915. He became a successful public corn breeder and a highly influential early promoter of hybrid corn – with a direct influence on the careers of several budding corn breeders.

Donald Jones, a graduate student and assistant to Dr. East hired after Hayes’ departure, invented double-cross hybrids. This involved a two-step process: four inbreds were crossed in pairs to produce two single-cross hybrids, and these, in turn, served as the seed parents for making double-cross hybrid seed that could be planted by farmers.  Double-cross technology permitted hybrid seed to be produced in quantity at reasonable cost – a huge breakthrough allowing the large-scale use of hybrid corn in North American agriculture.

George S. Carter, a Connecticut farmer, used single-cross seed produced at the Connecticut station in 1920 to produce the first commercial-scale double-cross hybrid seed in 1921. He sold this to other farmers in 1922. His double-cross hybrid involved one parent produced using two Burr White inbreds, and the other from two Leaming inbreds. Thus, George Carter was the first person in the world to sell true hybrid seed corn.

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Funk Brothers Seed Company, James Holbert and USDA

Eugene Funk and his family, based at Bloomington Illinois, were large farmers and seedsmen at the beginning of the 20th century. They were active in many aspects of Illinois agriculture and had developed their own open-pollinated varieties, Funk’s Yellow Dent and an earlier version, Funk’s 90-Day. Both were derived from the Midwest’s best-known variety at the turn of the century, Reid Yellow Dent. Reid Yellow Dent, in turn, was developed by Robert Reid and his son, James, in Illinois during the mid-to-late 1800s. It continues to be the most important original source for North American corn inbreds today, including various versions which were common at this time – one being an earlier-maturing version, Iodent, developed by Iowa State College, which figures prominently in the genetic background of many modern commercial inbreds.

(There is a large amount of older literature on the names and nature of the many open-pollinated (OP) corn varieties grown in about 1900. Discussion on them is beyond the scope of this article, but readers seeking more information are referred to an excellent, extensive review by Dr. A. Forrest Troyer, formerly with Pioneer, DeKalb and the University of Illinois. It is part of an equally impressive book called Specialist Corns edited by Dr. Arnel Hallauer of Iowa State University. Troyer’s review details the OP origins of many popular corn inbreds, including some from France. A non-pay-walled copy of the entire book can be down loaded from here.)

Funk began corn breeding including some inbreeding in about 1902. However, Funk reduced the hybrid work after a few years because of his inability to achieve yield improvements large enough to cover costs. Not discouraged, in 1915, Funk hired James Holbert, a new graduate from Purdue University, as his corn breeder. Holbert met Dr.  Hayes at Minnesota, at time of graduation, and Hayes encourage him to concentrate on inbreeding and hybrid crosses – which he did. Holbert began inbred development almost immediately upon arrival at Bloomington, starting with the selection of 500 parent-stock ears chosen after the examination of more than one million individual plants.

In 1916, Funk Brothers Seed Company began selling seed of a product called ‘Funk’s Tribred Corn,’ the first so-called hybrid corn to be marketed anywhere – even if it was actually a cross among three unrelated open-pollinated varieties. The sale of this product stopped after a few years because the yield boost was insufficient to cover the added cost. Funk sold its first true double-cross commercial hybrid in 1927.

In 1918, following pressure on Washington by Eugene Funk to ‘do more’ about corn diseases, the United States Department of Agriculture (USDA) established a corn breeding research station on the Funk farm at Bloomington, with Holbert as its new corn breeder. This station operated until 1937 when it was closed (or transferred to the University of Illinois according to one reference) and Holbert returned to breeding corn for Funk Brothers. During his 19 years with USDA, Holbert provided free advice and breeding material to many fledgling private corn breeding programs, and developed several important early inbreds and public hybrids.

Some of the early Holbert/USDA inbreds were called ‘A,’ ‘B,’ ‘Hy’ and ‘R4,’ and double-cross hybrids were produced by combining these with early inbreds, Wf9 and 38-11, from Purdue (the Purdue corn breeder was Ralph St. John), and L317 from Iowa State College (ISC, later to be named Iowa State University, with Dr. Merle Jenkins as the breeder). US 13 was an early double-cross hybrid with the pedigree, (Wf9 x 38-11) x (Hy x L317).

Funk Brothers was perhaps the most important commercial seed corn company in the central Cornbelt in the marketing of open-pollinated corn varieties and in early hybrid development during the first third of the 20th century. Funk’s was a prominent name in hybrid corn for many decades to follow.

In my era, Funk hybrid names/numbers always began with the letter, G. I finally discovered the explanation in The Founding of Funk Seeds, produced by the company in about 1983 (not available on the web). Apparently, at the beginning, farm publications in the US Midwest were reluctant to publish company names in their articles, only hybrid numbers. So Funk included the letters B and G in some of their hybrid names, hoping farmers would associate the letter with the company. No one seems to have recorded why B and G. By chance, G hybrids turned out to be better than B, so B was soon dropped. And Funk’s hybrid numbers all began with G in years to follow.

Eugene Funk died in 1944 and Jim Holbert in 1957. In 1967, ownership of Funk Brothers Seed Company was acquired by CPC International, a New Jersey-based corn processor that had extensive starch milling operations in Illinois, and with which Funk had had a cooperative working relation in Italy since Wold War II. That sale was considered by some to have seriously impaired Funk’s long-term success. The new owner placed a major emphasis on developing hybrids that were high in oil content (matching CPC’s then lucrative market for Mazola corn oil, a by-product of starch milling). This meant reduced attention to agronomic traits like higher yield and standability (resistance to lodging) that were important to farmers.

A high point for Funk’s was the year 1970 when this company’s hybrids proved resistant to a widespread epidemic of Southern Corn Blight. The reason was that, unlike most other companies, Funk recognized that use of a source of male sterility then widely used in hybrid seed production caused susceptibility to the disease. Funk retained use of hand detasseling in seed production and its sales soared temporarily. The hybrid Funk’s G4444 soon became the most popular hybrid in the US Midwest in the early 1970s – replacing DeKalb XL45 that had been the favourite in the decade before. Funk’s G4444 was actually a cross between two public Minnesota inbred (A619 and A632), which means that it was likely also available from other companies, but it was sure a commercial success for Funk.

But poor stalk quality was to damage the marketing fortunes of Funk’s trademark ‘G’ hybrids by the mid 1970s and farmers switched to competitive products, especially new hybrids such as P3780 from Pioneer with superior standability. Sales of Funk corn hybrids plummeted. Funk hired two well-respected university corn geneticists, in turn, to lead its corn research program – Dr. R.I (Bob) Braun from McGill University in Quebec and Dr. Steve Eberhart from Iowa State University (both of whom I knew and admired.) But it made no difference; Funk seed sales plunged.

Funk became a public company in 1972 with the name changed to Funk Seeds International. It was purchased by the Swiss chemical/ag-chemical company Ciba-Geigy in 1974. The name trade name, Funk’s, was discontinued by Ciba-Geigy in 1993 – a sad ending for such an important name in US and Canadian corn history.

Ciba-Geigy merged with another chemical company, Sandoz to form Novartis in 1997 and a further merger with AstraZeneca led to the creation of Syngenta in 2000. Syngenta is now owned by ChemChina and Syngenta sells seed corn under the NK trade name. (‘NK’ comes from Northrup-King, a Minnesota-based seed company dating back to the 1800s that was purchased by Sandoz in 1969.)

Note that there was an unrelated and smaller corn seed company based in Indiana called Edward J Funk and Sons that used the tradename ‘Supercrost.’ The two Funk companies were often confused. The Edward Funk company was sold in 1990 to the Garst Seed Company, Garst then being owned by a British chemical company, ICI. ICI later merged its various seed operations to form Zeneca. And through a subsequent merger with a Swedish firm, Zeneca became part of AstraZeneca.

In addition, Funk Brothers Seed Company had a number of ‘Associated Growers’ that were licenced to produce and market Funk G hybrids as independent companies. Funk seed corn production and sales in Canada were managed by an associate company in the 1940s. After the sale to Ciba-Geigy in 1974, several of these associates formed their own company that they named Golden Harvest. It was later purchased by Syngenta, though seed corn is still sold as ‘Golden Harvest’ hybrids in the United States.

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Henry Wallace and Pioneer Hi-Bred Corn Company

The Wallace family name is legendary in Iowa starting with the first Henry Wallace who arrived in the state as a Presbyterian minister in 1862, then became farmer, and later editor-in-chief of a publication called the Iowa Homestead.  His son Henry C. Wallace purchased another farm paper, which he renamed, Wallace’s Farmer, and served as a professor of dairying at Iowa State College (ISC, later Iowa State University). In 1921, he became the US Secretary of Agriculture.

Henry C’s son, Henry Agard Wallace, was born in 1888 and became an entrepreneur interested in corn improvement at an early age. As a youngster, he sold his first seed corn, 10 bushels produced from a cross between two open-pollinated varieties for $50. At age 16, he challenged the then-popular assumption that seed from ears of championship ‘show corn’ would produce superior crops the following year. A special yield test run by ISC and instigated by teenager Henry A and his dad, Henry C, showed that Henry A’s skepticism was well founded. Plants grown from show-ear seeds yielded no more.

The fallacy of superiority of show corn – which had only became a popular feature of fall fairs in the Midwest during the 1890s – impeded corn advancement for at least three decades to follow. Support for the assumed supremacy of show corn was so strong that it affected the judgement of corn industry leaders everywhere. Varietal yield trials, up until then largely unknown, began in Iowa in about 1920, spreading soon to other states and Ontario, and were effective in finally destroying the myth. If anything, plots grown from seed of show-corn-winning ears often yielded below average. Nevertheless, the modern view of what a ‘good-looking’ ear of corn should look like still stems from the corn-show era.

Henry A graduated from Iowa State College in 1910 and started corn breeding in a 10-foot-by-20-foot garden behind the family home in Des Moines in 1913. This was soon followed by more extensive breeding – though still tiny by modern standards – on a nearby farm owned by his uncle. A single-cross hybrid called Copper Cross developed by Wallace – which was a cross between an inbred from the variety Leaming and another from Bloody Butcher (known for its dark red kernels) – was entered in a newly created regional varietal performance trial. The hybrid yielded first in 1924 and its seed was produced on one acre of land near Altoona Iowa under contract with George Kurtzwell of the Iowa Seed Company. (Kurtzwell’s sister later proclaimed she detasseled Iowa’s entire hybrid seed corn crop that year.) The resulting 15 bushels of seed was sold in 1925 for $1 per pound.

Copper Cross was not a commercial success because of the low seed yield. Indeed, it was only sold for one year, and Wallace and partners shifted quickly to double-cross hybrids. But, as the first true hybrid corn sold in the US Midwest, the historical fame of Copper Cross is assured.

The corn program moved to newly purchased land at Johnston, north of Des Moines, at about this time. The Hi-Bred Corn Company was created by Wallace and two partners in 1926. It was renamed Pioneer Hi-Bred Corn Company in 1935.

As well as being a visionary and entrepreneur, Henry A. Wallace was a great communicator and promoter, and his ceaseless promotion of hybrid corn in Wallace’s Farmer was critically important to the fledgling hybrid industry.

The ‘farmer-salesman’ approach adopted by Pioneer in the 1930s worked remarkably well and is still the basis for most corn seed sales by major companies across North America.

Henry A became U.S. Secretary of Agriculture in 1933 thus ending his direct involvement with Pioneer. He later served from 1941 to 1945 as vice-president of the United States under President Roosevelt. Among other accomplishments as secretary and vice president, Henry A played a critical role in the creation of the Rockefeller-funded corn and wheat improvement program (later, CIMMYT) in Mexico.

Wallace attracted some outstanding people to his team including a farm boy and recent ISC graduate, Raymond Baker, who joined Pioneer in 1928. Baker became head of corn research in 1933.

I had the rare privilege of meeting Baker as well as author Bill Brown, then vice president of research and later to become Pioneer president, when I interviewed for a research position at Johnston in 1969. (The interview occurred in a nondescript three-story red-brick building on the Johnston property that was then the headquarters for the Pioneer corn research program – a far cry from the expansive Pioneer research campus that exists there today.) My interviewers also included Don Duvick and Forrest Troyer, two outstanding corn breeders and industry leaders, and good contacts in the years to follow. Such a rare opportunity for me (even though I did not take the offered job).

No story of the beginnings of Pioneer Hi-Bred is complete without mention of Garst and Thomas. An entrepreneur extraordinaire, Roswell Garst, persuaded Wallace in 1930 to let him produce Pioneer seed at Coon Rapids Iowa, about 50 miles northwest of Des Moines, and sell it in western Iowa and states further west. (Thomas was a minor player in the venture and his share was soon purchased by Garst.) This turned out to be a financial gold mine for Garst. It continued until his death in 1977 when Pioneer reclaimed these production/marketing rights. Garst’s son, Steve, established Garst Seeds in 1980; it was sold to Imperial Chemical Industries (ICI) in 1985. The rationale I’ve heard for the original arrangement with Rosell Garst (true or false??) is that Wallace did not expect his hybrids to sell as far away as Coon Rapids; therefore, the Garst and Thomas venture was not expected to compete with a Des Moines/Johnston-based business.

Pioneer Canada had a similar beginning with the initial business being that of a farmer and businessman who later sold out to the Johnston-based company. I’ll write more about the Canadian connection in a later column.

I also had the privilege of visiting Roswell (aka Bob) Garst and his various businesses in Coon Rapids in about 1972. Garst was a very colourful, aggressive and highly opinionated character who had became nationally famous for hosting Soviet leader Nikita Khrushchev during his 1959 visit to Iowa. Bob Garst would have made Donald Trump look like a wallflower.

Pioneer’s seed corn business was sizable right from its beginnings but sales really boomed during the 1970s and years to follow, thanks to an earned reputation for stress tolerance and superior stalk quality. There is an intriguing internet thread here where Midwest farmers describe why they switched to Pioneer hybrids, and away from Funk’s, at that time.

Pioneer’s success might be credited to at least three factors: 1) extensive use in breeding of the Iowa Stiff Stalk Synthetic, a special population produced by Dr. George Sprague, a USDA breeder at Iowa State College based on early inbreds with superior stalk quality (reference here), 2) a huge pre-release hybrid testing program with many locations all across corn-growing regions of North America, and 3) a unique three-replicate testing process introduced by Don Duvick, then head of corn research. The latter involved one rep planted at a ‘standard’ plant density, one with 5000 fewer plants per acre, and one with 5000 more. I recall Don discussing this this over lunch in Chicago in about 1970. (I tried to persuade him to go with two reps at standard and two at 5000-plus – advise which he rejected.) He obviously made a brilliant decision that paid off hugely for the company. Pioneer became the North American leader in corn seed sales in 1981, and I think it has been there most of the time since. (It reached 67% of Canadian seed corn sales during the late 1990s though the percentage declined after then.)

The company changed its name to Pioneer Hi-Bred International in 1970 and went public in 1973. This coincided with a major company reorganization and expansion beyond North America including a new corn-breeding program in France. Pioneer was first traded publicly on the New York Stock Exchange in 1995. Twenty percent ownership was purchased by DuPont in 1997 and the remaining 80% in 1999. Following DuPont’s merger with Dow to form DowDuPont in 2017, Pioneer is now a brand name for the new corporate entity, Corteva AgriScience.

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DeKalb Agricultural Association

DeKalb, the seed corn company, had its beginnings in 1912 as the DeKalb County Agricultural Association created by a northern Illinois farm organization, the DeKalb County Farm Bureau. The association had the goal of ensuring good seed quality for its members – an apparent problem at the time. Tom Roberts was hired as county agent and as the manager of the association. The association also hired Charlie Gunn who figured prominently in the corn-breeding program to follow.

In 1923, Roberts and Gunn invited Henry C. Wallace, then US Secretary of Agriculture, to speak at an association event (the train from Washington DC to Des Moines travelled through DeKalb) and Wallace shared his enthusiasm for corn improvement using hybrids. Roberts and Gunn began corn inbreeding in secret that summer but did not tell the association directors until five years later. This was done, apparently, to keep a local competitor in the seed business from knowing what they were doing.

New inbreds developed by DeKalb were crossed with later-maturing inbreds provided by Holbert at the USDA station at Bloomington IL to produce double cross hybrids. The first production of commercial seed was in 1934; a major drought that year meant only 325 bushel of hybrid seed was produced on 75 acres. The sale of this small quantity in 1935 represented DeKalb’s first sale of hybrid corn seed. Not discouraged, they produced 14,500 bushels on 310 acres in 1935 and 90,000 bushels in 1936. The genius of Roberts and Gunn was in producing large quantities of hybrid seed right from the beginning and advertizing aggressively, especially in the farm magazine, Prairie Farmer.

These advertizements resulted in requests for purchases from farmers all across the US Midwest, including maturity zones much different from northern Illinois. Ralph St. John, a prominent corn breeder Purdue University, was hired to serve as a corn breeder for DeKalb, focusing on longer-season maturity zones. Seed production facilities were established in Nebraska, Iowa and Indiana in 1938. The first DeKalb corn was sold in Ontario in 1939.

Four million acres of the Midwest were planted with DeKalb hybrids in 1940.  The hybrid, DeKalb 404A, introduced in 1940 became hugely popular in the central Cornbelt, with more than 500,000 bushels of seed sold in 1947. That was followed by XL45, an earlier maturing hybrid that proved highly successful during the 1960s – with its fame enhanced when Clyde Hight used it to become the first Midwest farmer to average more than 200 bushels of corn per acre on a substantial acreage.

DeKalb was the largest US seed corn marketer from the mid 1930s until the 1970s when it was surpassed by Pioneer.

The DeKalb Agricultural Association was renamed DeKalb AgResearch in 1968. A joint venture with Pfizer in 1982 resulted in the name DeKalb-Pfizer Genetics that became the DeKalb Corporation in 1985. The seed portion was spun off and named DeKalb Genetics Corporation in 1988. (The DeKalb Corporation also had extensive investments in non-agricultural ventures including petroleum.)

Monsanto purchased 40% of DeKalb in 1996 and the rest in 1998. With Monsanto’s purchase by Bayer completed in 2018, DeKalb is now a tradename for Bayer.

On a personal note, I was very close to DeKalb for several years during the 1970s when we combined to test some of my ideas for corn inbred selection (I was a crop physiologist with the University of Guelph at the time) in their commercial breeding system in northern Illinois. I was never a paid consultant though DeKalb did sponsor a couple of my graduate students. This ended when there was a major change in DeKalb research management – triggered by a major loss in market share to Pioneer – and I left the University of Guelph to work for a farm organization – both occurring in the early 1980s.

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Lester Pfister and PAG

Lester Pfister, born in 1897, quit school at age 14 to farm near El Paso, Illinois, and thereafter developed a system for yield-test comparisons of open-pollinated varieties. In that era, yield-test comparisons were very uncommon; farmers generally chose seed for the following year based on ear characteristics – usually as they hand-harvested the ears of their own crops – but also in purchases of seed ears from neighbours. (Farmers would commonly pay more for seed still on the ears – versus shelled – so they could see what the ears looked like.) From this beginning, Pfister developed a variety called Krug Yellow Dent that became very popular in central Illinois. He began inbreeding Krug in 1925.

Pfister struggled with near financial ruin caused by the Depression and droughts in 1934 and 1936 but persevered, producing 37,000 bushels of hybrid seed for sale in 1937, generally using inbreds provided by Holbert at the USDA station at nearby Bloomington. Pfister also benefitted from some national publicity generated by a feature story in Life magazine that claimed he was the inventor of hybrid corn. He used this publicity very skillfully to expand his business.

Pfister’s approach to production and marketing was almost the opposite of DeKalb’s. Pfister recognized that he could not produce and market seed on a competitive scale for the entire Cornbelt, so he developed a system of associated growers – similar to Funk’s – that was well-developed by 1943. In fact, that year the franchised growers purchased the parent company from the Pfister family to become a cooperative called Pfister Associated Growers. It became the P.A.G. Division of W.R. Grace, a fertilizer/chemical company, in 1967.

P.A.G. Seeds became a division of Cargill in 1971 or 1972 and the brand name changed to Cargill Seeds in 1987. It was then bought by Dow Agrosciences in 1998 and merged with Dow’s existing brand, Mycogen, to form Dow Seeds. It is now part of Corteva Agriscience following the 2017 Dow-DuPont merger.

As an aside, when I started farming near Guelph in 1972, two of my earliest hybrids were PAG SX42 and SX47.

Public Corn Breeding

In this article, I have focused on commercial hybrid corn pioneers rather than public breeders. That’s partly for brevity (recognizing that the article is not that brief, in any case) and partly because their histories are more interesting and less well known.

However, it’s important to give credit to the role of public breeders. USDA, which converted its corn research effort to a dominant emphasis on corn hybrid development in about 1921, was responsible for many early inbreds and hybrids. US 13 was one of the earliest hybrids, created by Holbert at USDA-Bloomington, but there were many others.

Work at the University of Illinois, the Connecticut Agricultural Experiment Station, the Carnegie Cold Harbor laboratory on Long Island, New York has been described, along with public corn breeding at the University of Minnesota, Iowa State College and Purdue University. But other land-grant programs in the US Midwest also established inbred and hybrid development programs at an early date including Ohio, Nebraska, Missouri and Illinois.

The hybrid Iowa 939, which was also sold under other names, was an early success. It was even grown in Ontario in the late 1930s even though too late in maturity to be considered adapted.

I’ll make special mention of the corn breeding program of Dr. Norman Neal at the University of Wisconsin at Madison. Neal was a New Zealander who came initially to Wisconsin to study perennial forages. However, a temporary job in the breeding nursery of Dr. Alexander Brink (Brink is better known for his pioneer work on alfalfa breeding but also worked on corn) to earn some needed cash, led to a life-long commitment to corn. Closely associated with Neal‘s program, from which hybrids were made available to farmers as early as 1933, was an associated corn breeding program of A.M. Strommen at the Spooner research station of the University of Wisconsin, many miles further north. Some great early-maturing inbreds from Madison and Spooner, Wisconsin formed the base for most early hybrids in the United States and Canada. In fact, a check of the list of hybrids approved for sale to Ontario farmers in the early 1940s showed that almost all were of Wisconsin origin, including the first known fields of hybrid corn grown in 1937. More on that will follow in a future column.

Early Expansion of Hybrid Corn and the Significance of Drought

The acreage of hybrid corn increased steadily after 1930, led by the State of Iowa, thanks in large part to the promotional efforts of Henry A. Wallace, Wallace Farmer and Iowa State College. However, it was probably the drought years of 1934 and 1936 that caused the greatest impetus. The drought of 1934 was severe and widespread across the entire Midwest, and the superior stress tolerance of hybrid corn was very apparent that year. Although the 1936 drought was centred further west (a total disaster in states like Kansas but not so bad in Illinois and eastward), it reinforced the lesson of 1934. Hybrid corn was more drought tolerant.

Richard Sutch (2010) has presented convincing evidence that drought was responsible more than anything else – including the typical yield boost from heterosis – for the major conversion of US Midwest corn acreage to hybrids by 1940.

Here are two graphs from Sutch’s paper:

Sutch photo #1

Sutch photo #2

The rapid expansion in hybrid corn acceptance led to a massive increase in the number of companies producing and marketing hybrid corn. A review by USDA of mergers and acquisitions in the US hybrid corn industry, completed in 2004, states that 190 companies produced and/or sold hybrid seed corn during the 1930s.

A Big Thank You

In the 1930s, the average yield of corn in the US Midwest was about 30-40 bushels per acre – as it had been for many decades before. Indeed, there are suggestions that this yield was trending lower in some areas of the United States, especially in the eastern Cornbelt, because of the combination of corn diseases and soil degradation; 100 years of farming by then had meant important reductions in soil organic matter content. The increasing prevalence of corn diseases was the reason for the establishment of the USDA corn research station on the Funk farm at Bloomington in 1917.

Some have argued that the yield benefit from hybrid technology has been overstated; perhaps if the equivalent amount of breeding effort had gone into the improvement of open-pollinated varieties, the superior yield levels of today (typical state averages of 170 to more than 200 bushels per acre) would still have been realized. But that said, it’s highly unlikely that this would have occurred without the profit incentive for corn breeding with hybrid technology and the need for farmers to repurchase seed each year.

Note that in the early days of hybrid corn, almost all inbreds were all publicly available and farmers had the right to produce their own hybrid corn seed if they chose to do so. In fact, very few did so and, of those who did, many went on to develop their own hybrid seed corn companies.

For many years, the number of small seed corn companies in the US and Canada was huge. Most of these would have sold hybrids produced from publicly available inbreds, meaning the same hybrids were available from many different suppliers. That’s not really true now for reasons of economies of scale which have reduced company numbers in almost every area of modern commerce, and the fact that almost all corn breeding is done nowadays by private companies.

Hybrid corn is a remarkable North American, and global, success story.

Acknowledgements and Reference Material

In addition to the links provided below, I thank the following individuals for their help in providing key references and links thereto:

Karen Daynard, Dr. Greg Edmeades, Dr. Gustavo Garcia, Dr. Peter Hannam, Daniel Hoy, Dr. Bruce Hunter, David Morris, Dr. Raymond Shillito, and Dr. Stephen Smith.

If you spot anything in this article which is factually incorrect, please contact me at TerryDaynard@gmail.com, so that the correction can be made. Thanks.

  1. General references on hybrid corn history

Crabb, Richard, 1992, The Hybrid Corn-Makers, Golden anniversary edition. West Chicago Publishing Company. (This edition includes a complete copy of the first edition, also by R. Crabb, published in 1948 by the Rutgers University Press.)

Hallauer, Arnel R. 2009. Corn Breeding. Iowa State University Research Farm Progress Report.

Sprague, George F., ed. 1977. Corn and Corn Improvement.  American Society of Agronomy.

Sutch, Richard. 2010. The Impact of the 1936 Corn-Belt drought on American farmers’ adoption of hybrid corn. University of California, Riverside and the National Bureau of Economic Research.

Troyer, A. Forrest. 2000. Temperate Corn: Background, behavior, and breeding. Chapter in Speciality Corns, second edition, ed. Arnel R. Hallauer. CRC Press. (Book can be downloaded here.)

United States Department of Agriculture, Economic Research Service. 2004. Mergers and acquisitions rose in the past three decades. Chapter from The Seed Industry in US Agriculture.

Wallace, Henry A., and William L. Brown. 1988. Corn and Its Early Fathers, revised edition. Iowa State University Press

  1. Funk Brothers Seed Company

Funk Bros. Seed Co. Publication date not stated but probably 1941. Funk Farms birthplace of commercial hybrid corn. A history of hybrid corn. Document 633.15709773 F963f. Illinois Historical Society.

Funk Seeds International. Publication date not stated but probably 1983. The Founding of Funk Seeds. Compiled by Dr. Leon Steele. Ciba-Geigy Corporation. 

  1. Pioneer Hi-Bred Corn Company

Brown, William L. 1983. H.A. Wallace and the development of hybrid corn. The Annals of Iowa, State Historical Society of Iowa, Vol 47 (2), 167-179.

Dupont Pioneer milestones. Pioneer.com web site.

Pioneer Hi-Bred International, Inc. History. 2001. International Directory of Company Histories, Vol. 41. St. James Press.

Jarnigan, Robert A. 2016. A brief summary of Pioneer history on the 90th anniversary. Reproduced from the Iowan magazine.

  1. DeKalb Agricultural Association

DeKalb Genetics Corporation History. 1997. International Directory of Company Histories, Vol. 41. St. James Press.

Northern Illinois Regional History Center. Undated. DeKalb AgResearch, DeKalb, Illinois. Collection item RC 190.

Wikipedia. DeKalb Genetics Corporation.  Web site.

  1. Pfister Hybrid Corn Company.

Broehl, Wayne G. 1998. Excerpt from Cargill, Growing Global. University Press of New England.

Fussell, Betty H. 1992. Excerpt from The Story of Corn. University of New Mexico Press.

How and When Corn Came to Canada, and How it was Grown

Champlain’s Missed Rendezvous

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It’s one of the most significant missed rendezvous in Canadian history – and one of the grandest journeys. Samuel de Champlain, explorer and champion of a fledgling French Canada, had been late for a gathering of native leaders near what was to become Montreal in the spring of 1615. He rushed to catch up with them using two canoes and 10 skilled, mostly indigenous, canoers. They paddled and portaged up the Ottawa River, across Lake Nippissing and down the French River to Georgian Bay – then down the length of its rocky eastern shore with its 30,000 granite islands and wind-blown, scraggy jack-pine trees. After 800 kilometers in 23 days, they arrived suddenly at what must have seemed like an Eden – good farmland and corn farmers in what’s now called Huronia in northern Simcoe County.

That transition in geography is just as unique today as it was then – as anyone who drives south on Ontario Highway 400 from Port Severn into Simcoe County – from a Precambrian landscape to quality farmland – can attest.

This would not have been Champlain’s first encounter with corn farming. Some indigenous farming was done on modest scale by nations along the Ottawa River through which he had travelled. He likely saw corn fields during his historically significant trip to Lake Champlain country in 1609 where he and his companions encountered and shot several Mohawk warriors. But the scale and grandeur of farming in Huronia would still have been a huge surprise.

(After reaching Huronia, Champlain became part of a large group of Huron and Algonkian nation warriors who attacked an Onondaga town near what’s now Syracuse, New York – a raid which was actually the reason for the missed appointment in Montreal and a fascinating story in itself – but I won’t enlarge here. You can read about it all in the classic, Champlain’s Dream, by D. H. Fischer)

Champlain spent that autumn and winter in Huronia visiting about 20 Huron and Petun towns/villages, who collectively called themselves, ‘Wendat.’ His detailed records of what he saw constitute much of what we know about this remarkable farming society during the mostly pre-European-contact era (“mostly” because some European goods were present in interior indigenous communities decades before the arrival of the first European explorers, thanks to well-developed indigenous trade networks).

Champlain estimated that the Huron confederacy numbered about 30,000 people, including towns as large as 5000 residents. When combined with an estimated 15,000 Petun people living just a few km to the west, this represents a Wendat population about as large as what exists in northern Simcoe County today.

These communities were all based on the growing of corn – huge quantities of corn in huge fields. Champlain reported seeing fields as large as 1000 acres and Gabriel Sagard, who wrote about Huronia 15 years later, said, “[The large fields were] the reason why going alone sometimes from one village to another I usually lost my way in these cornfields, more than in the prairies and forest.” The Wendat grew corn in quantities sufficient to produce food reserves for two or more years and also for trade with neighbouring non-farming Algonkian nations – trading for furs and materials such as copper from near Lake Superior. The Wendat did grow plants other than corn (primarily beans, squash, sunflower and tobacco) and their meals sometimes contained meat and fish, but their diet was dominated by corn.

I’ll come back to Huronia later, but first I want to shift back to an era 600 years or more earlier.

The Beginnings

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Most readers will know about the transition of wild teosinte into corn (or maize) in Mexico about 5000 BC. From this beginning, corn culture moved slowly northward, entering the southwestern United States in about 2000 BC. It became the basic food for several native societies that flourished in New Mexico, Arizona and adjacent states up until about 1000 AD.

From the southwestern United States and/or northeastern Mexico, corn worked its way north and east, and especially along the Mississippi River system, where it flourished sometime after 800 AD. The largest example of a Mississippian, corn-based civilization is the former city of Cahokia in Illinois, near St. Louis. It peaked from about 1000 to 1400 AD and likely had a population in excess of 25,000 people. Cahokia was the largest city north of Mexico at the time – indeed, matching or exceeding some major European cities in size. This was a city and civilization based on corn, but supplemented with some other food crops.

There were many other smaller but significant corn-based communities elsewhere along the Mississippi-Missouri-Ohio river system. Corn culture spread up the Ohio River valley – then via the Alleghany River into the present New York State – and from there a few kilometers north into the present-day Ontario.

Estimates as to when corn entered Ontario vary. Some say as early as 500 AD. Georges Sioui, in his book Huron Wendat, The Heritage of the Circle, refers to a radiocarbon dating to 615 AD of corn residue found near Rice Lake Ontario. A summary by the Ontario Archaeological Society claims the presence of corn in Ontario near the end of what’s known as the Middle Woodland period, i.e., 700-900 AD. There seems to be broad agreement corn’s dominance as a food source was well established in Ontario by 1000 AD.

When I first posted this column, I raised questions about how corn could have appeared in Ontario as early as 500 or 615 AD if it did not have a significant presence in the Mississippi and Ohio Valleys until a few several centuries later. I was also puzzled about how corn could have been grown in a sporadic manner during the introductory period given this crop’s vulnerability to wild animals. Small fields of corn within forests would have been decimated – just as they would now – by birds, raccoons, squirrels, deer and other animal pests, as well as over-run by weeds. It would seem that corn would have required decent season-long husbandry throughout the full season in order to ensure anything much at harvest.

Since the initial posting, I’ve learned both puzzles may have been answered – first by the discovery of corn remnants in southern Ohio dating back to about 200 AD – and second that corn was far from the first farmed crop in Eastern North America. Bruce Smith  and others have provided documentation that corn was actually a ‘Johnnie-come-lately’ to crop agriculture in this part of North America. Other plants including sunflower, cucurbits (gourds), and some chenopod species (lamb’s quarters and goosefoot) were domesticated and grown as farmed crops (i.e., planted, tended and harvested –  and with plants being modified genetically by human selection) as early as 2000 BC – two millennia before corn. By the time corn arrived as an imported species from Mexico and the southwestern United States, farming skills would have been well developed (even if farmed crops did not yet dominate the human diet).

Given that corn was present as a minor species in Ohio in about 200 AD, it’s not unreasonable for it to have arrived in Ontario by 500 or 600 AD, as noted above.

A large puzzle remains: If corn was present in middle/eastern North America by 200 AD, why did it take until at least 800 AD – and perhaps after 900 AD – before it became a major food crop in the Mississippi/Ohio river basins?

That this is so has been determined by analysis of the relative presence of the carbon isotope C-13 in human bones. The ratio of C-13 to C-12 (the usual form of carbon) is higher in organic compounds created by C4 photosynthetic species like corn than with most other farmed and wild plant species that have C3 photosynthesis. A higher concentration of C-13 in human bones, caused by a corn-dominated diet, was not apparent until after 800 AD.

Smith suggests that corn may have been used primarily for ceremonial purposes before 800 AD (like tobacco), or perhaps a long duration was required until productive corn varieties adapted to longer summer day lengths had evolved. (Neither explanation is that convincing in my view.)

In any case, the transition to a corn-dominated food system, once it began, spread rapidly within a period of 200 years or less from the Cado culture in eastern Texas right through to southern Ontario.

Archaeological records show corn was well established in southern Ontario by 1000 AD and indigenous people were highly dependent on corn for food, centuries before their first contact with white man.

Ontario Corn Farming After 1000 AD

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Thanks to the efforts of Ontario archeologists, we actually know a great deal about indigenous peoples in Ontario beginning 1000 AD. Most of southern Ontario and up-state New York was populated by people who have been collectively called ‘Iroquoian.’ The Ontario Iroquoian were closely related to other indigenous nations in states south of New York, but were surrounded on the west (Michigan and extreme southwestern Ontario), north (about everything north of Huronia) and east (Ottawa Valley, most or all of Quebec, Atlantic Canada and New England) by a much larger group of nations known collectively as Algonkian. The Algonkian people in Michigan and New England were also corn farmers, but in Ontario and Quebec they were dependent (with a few exceptions) on hunting and fishing – and on trade for corn with nations like the Wendat.

(A note on indigenous names is in order here: I am not aware of any reaction to ‘Algonkian,’ but ‘Iroquois’ and ‘Iroquoian’ seem to be universally disliked by those so labelled. ‘Haudenosaunee’ or ‘People of the Longhouse’ are what I’m advised by a Mohawk friend to use to refer to the collective Mohawk, Oneida, Onondaga, Cayuga, Seneca and Tuscarora members of the Six Nations Confederacy. But when I asked him about the inclusion of the Wendat and other such nations, he had no advice. Wendat author Sioui recommends ‘Nandoueks’ to refer to the larger grouping, though I note he says it refers to “Wendats, Iroquois and other ethnically related Native groups,” which doesn’t solve my problem. I’ve not seen ‘Nandouek’ used elsewhere; hence, my ‘solution’ is to use ‘Iroquoian’ for the collective but not ‘Iroquois’ for any of its component groups.)

Much is made of the ‘Three Sisters’ – corn, beans and squash – in North American indigenous agriculture; however, archeologists report no indication of beans or squash throughout southern Ontario until at least 1400 AD, and only one archeological report of a single sunflower seed before then (dating to about 1350). Tobacco, used for ceremonial/religious purposes, arrived in Ontario about as early as corn.

Much of southern Ontario was unoccupied for extended periods of time and the occupied areas changed over the centuries. At the time of Champlain’s visits, in addition to the Huron and Petun, there were about 40,000 people known as Neutrals to the French – or Attawandarons to the Wendat – who lived roughly within the triangle between Oakville, St. Thomas and the Niagara River. Although information about the Attawandarons is much sparser than for the Wendat, it’s clear that their culture was almost identical.

There is ample evidence of Iroquoian culture north of Lake Ontario and into eastern Ontario during years prior to Champlain – people were closely related either to the Wendat, or to the Onondaga and Oneida people concentrated southeast and east of Lake Ontario.

When French explorer Jacques Cartier visited the sites of present-day Quebec City and Montreal in 1534-1535, he encountered corn-growing people who are now considered to have been members of the Onondaga nation. However, there was no sign of them when Champlain arrived about 70 years later; they are presumed to have been decimated by European diseases and/or warfare with Algonkian nations to the north.

Iroquoian Corn Culture

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From F.W. Waugh. 1916. Iroquois Foods and Food Preparation

There is a good amount of available information on the culture and nutrition of Iroquoian nations, both from Europeans associated with the Huron people (Récollet and Jesuit missionaries as well as various visitors who wrote), and from similar writings about the Six Nations in New York State (especially the Seneca people who lived southeast of Buffalo).  Details on how that corn was grown and on the many dozens of food dishes based thereon, are well described in two historically important books – by A.C. Parker, NY State Museum, 1910, and F.W. Waugh, National Museum of Canada, 1916. (Details are provided below.)

They grew flint, dent (they called this ‘she-corn’), sweet and pop corn with the occasional mutant ear of pod corn as well (developed glumes around each seed), and both white and coloured.  Effort was taken to ensure varietal purity, though some cross pollination was encouraged.  The well-tillered plants usually had two to three ears per stalk, and 100 to 400 kernels per ear.

The men cleared the land by girdling trees and burning the dead tree skeletons a year or two later. Except for that, corn farming was done by women with help from children and slaves. (There is not much information in what I’ve read about slaves other than to acknowledge their existence; I’ve guessing that their numbers were quite small.) Corn seeds were planted, several at a time, into holes three feet or more apart. The seed was often treated with a water solution containing extracts of several wild plants to discourage crows.

Dead weeds from the previous year were cut off and removed at planting time. Weeds were removed by hoeing throughout the season. Fields were sometimes burned after harvest or before planting in springtime for pest/weed control.

After corn emergence, beans were planted, sometimes in each hill, sometimes in every seventh hill. Squash was commonly planted between rows. Fertilizer was not used though ashes would have provided some nutrients and beans may have provided some legume nitrogen.  Only certain East Coast tribes used fish as fertilizer and there is evidence that this technique was adopted only after contact with Europeans.

Worth noting is that these folks were totally into no tillage, the only tillage being the opening of holes for seed planting with a sharpened stick, a piece of deer antler or something similar. Even the most ardent no-till farmer in the 21st century does more tillage at seeding time than that.

Harvesting began with immature ‘green’ corn, some of which was roasted and preserved for winter food. Then came dough-stage harvesting, and finally mature corn.  Several foods were made from corn at each stage.  Mature corn was harvested, husks attached, and carried to the village or a central location where all but two or three husks were removed – generally at large social bees.  (They say young men often helped because it was a good place to meet girls.) Remaining husks were breaded to form strings of ears which were then suspended from the roof, walls and interior posts of longhouses until dry.  Most ears were then shelled and the grain placed in large bark bins up to six feet in diameter and height (up to 130 bushels) –  generally within the longhouses, though sometimes outside with bark roofs.

Harvested ears were also stored in cribs made of poles and bark or, when dry, in long-term, hidden, underground granaries.  These granaries, on well-drained sites, were commonly five-foot deep, lined with husks, grass or boughs, and covered when full with these same materials and then soil.  In fact, the lucky discovery (and theft, some say) of in-ground corn granaries prevented the Pilgrims from certain starvation during their first winter at Plymouth in 1620-21.

Enough corn was grown to provide a two- or three-year supply and also for trading.  Fur traders were regular customers in later years.

French governor Denonville and his troops spent ten days in 1687 burning Seneca corn bins and wrecking crops east of Niagara.  His claim of 1,200,000 bushels destroyed seems high, but they did demolish lots of corn.

In 1779, General Sullivan, as directed by George Washington, destroyed 40 Seneca and Cayuga villages and an estimated 160,000 bushels of corn.

The Jesuits report the average Huron diet was 65% corn, for a daily corn consumption of 1.3 pounds – or 8.5 bushels per person per year.  For a village of 2000 this meant about 17,000 bushels, or 430 tonnes.  Two years’ supply, plus corn to trade, meant grain stocks of at least 35,000 bushels (20 to 30 semi-trailer loads) – all carried in baskets for up to six miles from fields to the village. No wonder that early visitors reported Iroquois villages full of corn.

I can find no accurate record of yields though 30 bushels/acre seems reasonable, based on several sources.  Hence, a village of 2000 might require 600-1200 acres of corn.  The Lawson Prehistoric Indian Village museum (London) says the original settlement there numbered 2000 with at least 600 acres of crops.

References listed below provide ample details on planting and harvesting, and the many ceremonies and religious events associated with both.

2018-10-0027

From A.C.Parker. 1010. Iroquois Uses of Maize and Other Food Plants

Decimation of Wendat and Attawandaron in 1649-1651

This culture flourished in Huronia and among the Attawandaron until 1649-1651 when the Wendat and Attawandaron communicates were attacked and annihilated by the Five Nation Confederacy from New York State (later to become Six Nations when the Tuscarora nation from North Carolina moved north in about 1720). Although these were all Iroquoian people, there had been long-term hatred between Ontario- and New York-based nations. The attack was instigated partly because of that and partly because of a need for more beaver pelts for trade to Europeans. (The Wendat blocked direct trade between the Five Nation Confederacy and Algonkian nations to the north.)

The Wendat and Attawandaron numbers were badly weakened at the time by deaths caused by European diseases. Also significant was a split within Wendat society caused by the conversion of some of them to Christianity by Jesuits. (Converts were encouraged to avoid contact with those who weren’t.) In any case, after about 1651, the Wendat and Attawandaron communities in southern Ontario were no more. A few of them went to a new Lorette reserve near Quebec City, some to the Walpole First Nations near Wallaceburg. Some ended up in the Wyandot Reserve in Oklahoma. Some were absorbed by the Five Nations themselves, either as citizens or slaves. Only their memory remains in Huronia and the Attawandaron lands to the south.

In the decades to follow, some Iroquoian settlements were established in southern Ontario, especially along the north shore of Lake Ontario; the present Toronto and Prince Edward County were two sites. These were subsequently driven out before 1700 by Algonkian nations from the north, especially the Ojibwa who were known in the Toronto-Hamilton-Guelph area as Mississauga.

2018-10-0023.jpg

The Ojibwa were not farmers, at least not initially, and their culture in southern Ontario was mostly one of hunting and fishing. However, a series of land transfer agreements after 1780 meant that the Ojibwa people ended up in a number of mostly small reserves with limited potential for hunting. Though the land on most of these reserves is not well suited to farming, concerted efforts by government-appointed ‘Indian agents’ to promote agriculture meant that many Ojibwa people became farmers to some extent.

Six Nations Come to Ontario

The final chapter of indigenous farm culture in Ontario involves the Six Nations. In 1779, US army troops directed by General Sullivan and sent by George Washington destroyed the corn fields of about 40 Six Nations towns/villages in western New York State. (Washington accused the Six Nations of aiding the British though history suggests they were, on balance, neutral.) The resulting starvation forced the people to move near Fort Niagara on the east side of the Niagara River near Lake Ontario, to secure food supplies from the British. That relocation included temporary settlement in what’s now Ontario, west of the Niagara River. After the US War of Independence, Six Nations peoples were granted land along Ontario’s Grand River, and they settled at and southeast of the site of present city of Brantford. Some also settled in the Tyendinaga reserve near Belleville and on reserves near Cornwall Ontario, Montreal, and along the Thames River between London and Chatham Ontario.

The story of these settlements has been well described in many other places (including Arthur Ray’s book, I Have Lived Here Since The World Began, An Illustrated History of Canada’s Native People) and will not be repeated here. The Six Nations brought their corn-based culture with them and became well-respected farmers in Ontario on arrival. For a number of reasons, farming and corn growing diminished in the Six Nations reserves over the decades, but there has been a renaissance underway since the year 2000 – also a fascinating story, but beyond the scope of this article.

The European settlers in Ontario largely ignored corn except as a forage (silage) crop in most of the province, preferring to grow the grain crops that they had known in Europe (the exception being a few counties in extreme southwestern Ontario where corn remained dominant).

Then, starting about 1960, there was a resurgence in interest in corn in Ontario and within a couple of decades, it became, once again, the dominant grain crop in the province. Hence, the second millennium ended in Ontario just as did the first – with corn the dominant grain crop – albeit with a few changes in technology over those ten centuries.

Western Canada

Finally a note about corn in western Canada: Corn culture spread up the Missouri River Valley just as it did up the Ohio in years around and after 1000 AD. Corn was grown by the Mandan nation in the Dakotas, though with no evidence thus far of it being grown in prehistoric times in Manitoba. Wikipedia cites a reference stating that corn was grown by indigenous people at the mouth of the Red River, north of Winnipeg in 1790, a decade before the start of the Red River Settlement, though after the first visits by European explorers and fur traders.

Key References:

Cornelius, C. 1999. Iroquois Corn in a Culture-Based Curriculum. State University of New York Press.

Fischer, D.H. 2009 Champlain’s Dream. Vintage Canada.

Ontario Archeology Society. The Archaeology of Ontario: A Summary. https://www.ontarioarchaeology.org/summary-of-ont-arch

Parker, A.C. 1910. Iroquois Uses of Maize and Other Food Plants. New York State Museum. (Reproduced by Iroqrafts, Iroquois Publications, 1983 and 1994.)

Schmalz, P.S.  1991. The Ojibwa of Southern Ontario. University of Toronto Press.

Ray, A.J. 1996. I Have Lived Here Since the World Began, An Illustrated History of Canada’s Native People. Lester Publishing.

Sioui, G.E. 1999. Huron Wendat, The Heritage of the Circle. UBC Press. (English edition, original published in French, 1994, by Les Presses de l’Université Laval).

Waugh, F.W. 1916. Iroquois Foods and Food Preparation. National Museums of Canada. (Facsimile edition, 1973, and reproduced by Iroqrafts, Iroquois Publications, 1991).

White, R. 1985. Ontario 1610-1985. Dundurn Press.

Wright, J.V. 1966. The Ontario Iroquois Tradition. Bulletin 210. National Museums of Canada. (Facsimile edition in 1973.)

Some good places for information:

Iroqrafts, Oshweken, Ontario. http://www.iroqrafts.com/

Huronia Museum, Midland Ontario, https://huroniamuseum.com/

Crawford Lake Iroquoian Village, near Campbellville, Ontario. https://www.conservationhalton.ca/park-details?park=crawford-lake

Lawson Archaeological Site, London, Ontario. http://archaeologymuseum.ca/discover-archaeology/lawson-site/

Column revised December 29, 2019

A ‘ Kentucky Derby Weekend’ Tribute to the Remarkable Dr. Bill Duncan

Bill Elizabteh Duncan 1968

Bill and Elizabeth Duncan, 1968

I’ve met many outstanding people in my long and convoluted career, but without doubt, the most unique and special person was Dr. W.G. (Bill) Duncan with whom I spent a year’s post doc at the University of Kentucky (UK).

Twenty-eight years ago, Dennis Egli at UK wrote a tribute and eulogy published in the Journal of Agronomic Education. This column is about my year with Bill, which began on Kentucky Derby weekend, 51 years ago.

In early 1968, I was finishing my third of three degrees at the University of Guelph and wondering what I (or rather, wife Dot and I) would do next. Finding a university position in those days was no concern – there were lots – and I knew that I would likely end up on the faculty at Guelph, so it seemed important to get some experience elsewhere, ideally outside Canada. I visited, considered, and was treated royally by several US universities – and was offered an exciting job with Pioneer in Johnston, Iowa. (I’d love to enlarge on the latter as it involved the opportunity for lengthy interaction with some corn legends including Drs. Bill Brown, Don Duvick, Forrest Troyer – and Ray Baker. Baker was brother-in-law of Pioneer’s founder Henry Wallace and with Pioneer from the beginning – but I will maybe leave that for another blog.)

In the end, I opted for a year in the Agronomy Department at the University of Kentucky. While only a 10-hour drive from Guelph, Lexington was located on the opposite edge of the North American Corn Belt – a very different growing environment. A sub attraction was chance to get to know Appalachia, just to the east of Lexington. But the biggest draw was the opportunity to work with Bill Duncan, one of the most unusual personalities in the world of plant research.

As it turned out, I was the only grad student or post doc that Bill ever had, (post docs were quite uncommon then, but grad students were aplenty.) I guess that makes me unique as well.

Lexington in May

Lexington Kentucky in early May.

Bill never talked much about his past, other than his love for Hopkinsville and Christian County KY where he’d spent most of his life. But I learned from others how he’d sold a farm fertilizer business and returned to Purdue for a PhD degree. Egli details that well in his tribute.

I was also told that while he had offered to work free at the University of Kentucky, he was actually paid $1 per year; the payroll listing enabled him to have a library card.

The story was that he was very wealthy, but we saw few signs of it. He and his wife drove cheap cars and lived simply in a modest bungalow. His one luxury item was a Cessna 210 that they used to fly often (with Dot and me on board frequently) to interesting places all across the US. I found out years later that Bill Duncan came from a long line of W.G. Duncans who had once owned a coal mine in western Kentucky (you can Google for more information; see photo below). The coalmine business was sold to the giant Peabody Coal Company and the W.G. Duncan I knew became a multi-multi millionaire. But, except for the plane, almost none of this showed.

I arrived first in Lexington (Dot came later) on Kentucky Derby weekend, first weekend in May, the time of year when Kentucky looks its best – and it sure looked beautiful for someone arriving from Ontario where daffodils were just flowering. After church on Sunday morning, Bill suggested we fly in the Cessna to have lunch with an acquaintance in Starkville Mississippi, and that we did  – maybe an hour and a half trip, returning a couple of hours later when it was still light. (From that, I got the idea from that Starkville and Lexington were closely located – an error corrected a few months later when we had occasion to drive it – almost as far as from Guelph to Lexington.)

Duncan's plane 1968

The beloved Cessna. Bill filling it with fuel for another jaunt. Dot and Elizabeth to the right.

Bill and his wife loved great restaurants too. One Friday they flew us up to Purdue, supposedly to check out something from a Purdue scientist, but the real reason was dinner at a Morris Bryant restaurant in West Lafayette – then overnight at the Purdue U student union and back to Lexington on Saturday morn. Bill and his wife Elizabeth treated us like family and to many family events we went; I’d love to enlarge on that but won’t. They were so kind.

However, what I appreciated most from Bill was what he taught me about crop physiology, agronomy and the pursuit of science. Bill was unique in that he had no research funding nor any interest in pursuing such. What he did in the way of fieldwork was minimal – and all done using borrowed help, land space and other resources. In fact, I think the year I was there may have been his only one with field plots. We planted one small demonstration for him and a replicated test for me in half a day.

So, with no research requests to submit or reports to file, no teaching and no admin responsibilities, he was unique but also very busy – spending his time visiting with other faculty members, travelling the country and the world to meet others, reading, thinking and writing – especially the latter two. He had a flair for computer programming and this led to the development of sophisticated crop canopy models for which he garnered international fame, as described by Dennis Egli. In those days, there was no charge to him to use the UK computing facilities. That worked well for a prof with no operating budget – and the same for a post-doc without operating funds, too!

Because of Bill, I had a short but useful career as a crop modeller too. Here’s one publication

Kentucky was then at the forefront of research and farmer experience on no-till agriculture, and Bill made sure that I was well exposed to that. We toured many plots, met farmers, and had many discussions on why plants performed as they did. That experience led directly to my strong interest in no tillage and my first no-till plots at Guelph in 1969.

Perhaps the highlight of the year was our discovery of the significance of the black layer as an indicator of physiological maturity in corn. When I had visited and been interviewed by Pioneer earlier in 1968, Don Duvick had loaned me his PhD thesis from Washington University in St, Louis. In it, Don had briefly described the formation of a dark ‘closing’ area in corn kernels as they matured. I had only skimmed this briefly, but Bill read it more thoroughly and mentioned this in our discussion the next day.

What followed was some daily kernel sampling of the four hybrids I’d planted that spring, A paper followed, The black layer and grain maturity in corn. The black layer is known by pretty much everyone who works these days with corn.

Black layer in corn Dupont Pioneer

Black layer development in corn. Photo courtesy of DuPont Pioneer.

Duncan had a million ideas, some which he could test using the UK computer (no desktops in those days, only the UK mainframe) and many others that he tested with endless discussions involving me and most of the Agronomy faculty.

Then the year was over and my scholarship funding from the Canadian NSERC program ended. It was time to move on. Dot and I moved back to Guelph.

Our ties with the Duncans weakened after that. He was disappointed that I didn’t go into international agriculture where he thought I’d contribute most, and my interest in agricultural extension (working directly with farmers) did not appeal to him to him at all. But we kept in close touch for many years, including his years spent in Florida, as Dennis Egli describes.

As a footnote, I had the opportunity, 33 years later, when I became an unpaid adjunct faculty member in Land Resource Science, University of Guelph, to try to emulate what Bill Duncan had done decades earlier at UK. However, it was different. You needed money for everything – use of the university computer, access to any greenhouse space, attend conferences and more – and I had no desire to rejoin the rat-race-chase for research money that I’d known 20-30 years before. The conversations that I had with other faculty members were just as rewarding as what I’d remembered from my UK days, but my attempt to become another ‘Bill Duncan’ proved largely unfulfilled. After a year and half, I moved on to something else.

I’ve had a career that has ranged widely: several years as a crop scientist at U Guelph and then exec VP for a major farm organization, stints as a university administrator, CEO of a bio-auto organization, and endeavours in renewable fuels, bioproducts, communications and nearly five decades of farming. But, the most productive and enjoyable was likely our year in Kentucky with Bill Duncan. I treasure every day we were there.

Duncan coal mine tokens

For history buffs: Token coins used as currency for employees of the W.G. Duncan Coal Company in Western Kentucky. A generation earlier than the W.G. Duncan I knew.

 

 

My Introduction to Dr. Christine Jones

2019-03-10 12_35_41-Welcome to Amazing Carbon!

For several years, I have occasionally encountered the name, Dr. Christine Jones, an Australian soil microbiologist. Perhaps because I’ve been spending more time recently reading about soil biology, I’ve encountered more references to her. Out of interest, I decided to investigate further. That was not too difficult given that she has provided links to her writings on a web site called, Amazing Carbon . The following is based on several articles posted there.

Dr. Jones is obviously deeply committed to soil improvement and the importance of soil microbial activity. What she promotes is a combination of both the orthodox and the unorthodox. There is no hint that any of this is done for personal gain or product promotion, other than for her own services as a consultant.

I like her emphasis on plant roots and root exudates because they are significantly more important for building soil organic matter than aboveground crop residues. She also emphasizes the importance of arbuscular mycorrhizal fungi (AMF) to soil health and plant growth.

Some of her other statements, however, make me quite uneasy.

She states in a March 2015 interview with Acres, the publication of an alternative-agriculture group in the United States, “If a plant photosynthesizes faster it’s going to have higher sugar content and a higher Brix level. Once Brix gets over 12, the plant is largely resistant to insects and pathogens.” I doubt that many plant pathologist and entomologists would agree that what is, effectively, lusher plant growth ensures pest resistance.

In the same interview, she expresses major concern about cancer caused by pesticides and other crop inputs: She states, “Not that long ago the cancer rate was around one in 100. Now we’re pretty close to one in two people being diagnosed with cancer. At the current rate of increase, it won’t be long before nearly every person will contract cancer during their lifetimes.” No mention is made of the age effect on cancer incidence (modern people live longer). When the age effect is removed statistically cancer rates are mostly stable over time or going down.

Dr. Jones expresses concerns elsewhere in her writings about claimed links between nitrogen fertilizers and health, and the general unhealthiness of modern farm crops and foods. These are claims that I don’t believe are much supported by most credible research.

On nitrogen, I also found this statement puzzling: “the application of high rates of inorganic nitrogen has many unintended negative consequences on-farm. These include deterioration of the water-stable aggregates important for soil structural stability.” Most soil scientists would argue, I believe, that nitrogen fertilizer at recommended application rates stimulates plant and root growth, thereby increasing the amount of soil organic material and helping to build water-stable soil aggregates. Of course, much depends on the definition of “high.” Maybe extremely high rates do affect soil as she states.

This excerpt, which appears in identical format in at least two or her articles, implies that crop plants are less affected by drought stress if surrounded by other plants (including weeds, I assume).

C. Jones drought photo

I was once involved in research on drought in corn and this disagrees with what we believed true then.

I am as keen as other farmers on cost-effective ways to increase the organic matter of soils. Dr. Jones devotes major attention to this subject. She expresses disappointment in scientists who say it’s difficult to do this, and presents her own numbers implying the converse.

I was intrigued by these paragraphs from a 2010 presentation at an agriculture and greenhouse emissions conference:

“Recent research by United States Department of Agriculture (Liebig et al. 2008) investigated soil carbon sequestration under a perennial native grass, switchgrass (Panicum virgatum) grown for the production of cellulosic ethanol.

“Despite the annual removal of aboveground biomass, low to medium rainfall and relatively short growing season, the USDA-ARS research, averaged across 10 sites recorded average soil carbon sequestration rates of 4tCO2/ha/yr in the 0-30 cm soil profile and 10.6tCO2/ha/yr in the 0- 120 cm profile (Liebig et al 2008).

“The best performing site was at Bristol [South Dakota], where soil carbon levels increased by 21.67 tonnes in the 0-30 cm soil profile over a 5 year period. A soil carbon increase of 21.67tC/ha equates to the sequestration of 80tCO2/ha.”

I checked the Liebig et al paper (link here). You might want to do that too. It involves 10 farm sites located in Nebraska, South and North Dakota.

As it turns out, the 21.67tC/ha value is not statistically significant different from zero at even P<0.10; hence, it’s the same for the 80tCO2/ha.

At some locations, for some soil horizons, there was a statistically significant (P<0.05) increase in calculated amount of soil organic matter (SOM) per ha. (In one case, there was a significant decrease.) However, this was often the result of an increase in soil bulk density, over time, rather than a change in percent SOM per se. There were also examples of decreases in soil bulk density and that can lead to spurious errors in calculations of percent SOM. (See explanation at the end of this column.)

I’ve no doubt that long-term production of switchgrass will increase SOM, though probably not nearly so much as implied by Dr. Jones in her reference to this paper – or in other writings involving other cropping practices too. It would be nice to believe that there is some combination of crops, soil microbiology and management that will lead to large, rapid increases in SOM content, but the science I’ve seen it’s highly unlikely.

The part about Dr. Jones writing which intrigues me most involves her claims that a ‘healthy soil’ can virtually eliminate the need for synthetic fertilizer applications. I can understand this to some extent with nitrogen where a high SOM content coupled with high microbial activity will lead to rapid SOM oxidation and N release. But the P (phosphorus) part is more complicated. We do know that soils contain lots of elemental P that is generally in forms unavailable to plants. Can the right combination of roots, mycorrhiza and other microbes release enough to make an agronomically significant difference? Dr. Jones says yes. It would be great if she was right.

Unfortunately, there is a substantial probability that, just as in other areas as shown above, she’s off the mark on this one too.

I emphasize again that I am not questioning Dr. Jones’ commitment to better soil health, and have no thought that she’s presenting anything other than what she believes to be 100% true. As for me, I’ll be looking for support from credible, peer-reviewed scientific literature.

—-

How bulk density affects measurements of soil organic matter

In an untilled soil, or even one lightly cultivated or disked but not mouldboard plowed, the organic matter (OM) percentage is highest near the soil surface and declines with depth.

Consider a naturally compacted soil with an OM percentage of, say, 5% in the upper 5 cm, 4% in the next 5 cm and 3% for 10-15 cm  of depth That’s an average OM of 4% for a 15 cm soil core.

Now consider what happens if the top soil is loosened substantially, say with a tillage tool or biological activity. In this case, a 15 cm core may now sample soil that was originally in just the upper 12 cm of depth. The average OM percentage is now calculated as (5% x 5 cm + 4% x 5cm + 3% x 2cm)/12 cm = 4.25%.

The measured OM percentage has been increased from 4 to 4.25% simply by soil loosening.

The reverse occurs with compaction.

Some researchers try to adjust for this simply by adjusting for the change in core weight. For example, if the density drops by 20% with loosening, to use the example above, the researcher would multiply the OM percent after loosening by 15cm/12cm, or 1.25, in computing total OM content in the soil. Unfortunately, this does not eliminate the sampling error.

A more proper technique is to sample the soil to varying depths depending on soil density so that the same weight of soil is sampled for all comparisons. Other approaches involve measuring the density and OM percentage for 5 cm soil depth increments and making calculations based on what would occur if the bulk density was the same for all layers.

Bottom line: Be very cautious in interpreting published data involving differences in percent soil organic matter when there are also differences/changes in soil bulk density (which is usually the case).

While I am at it, I believe there is another common error/bias in soil OM data involving comparisons of tillage with no tillage. With tillage, OM is incorporated into the soil and all soil samples taken thereafter include the incorporated OM. However, with no tillage, above-ground residue remains on the surface and is usually avoided in taking soil samples. Hence, the OM benefit with no tillage may be underestimated in these comparisons.

 

 

 

Can We Improve the Soil Sustainability of a Corn-Soybean Crop Rotation?

 

Corn-soy2

 

This is a personal analysis of our own farm. It’s posted here because the thought process and information might be of interest to other farmers asking the same question.

I’ll start with the conclusions. The explanation of how I reached them is provided in detail below.

I’d best call these interim conclusions as they are very likely to change; this is a subject on which I have much to learn. But based on what I’ve garnered thus far, these seem like the essentials:

  1. A rotation of corn and soybeans is inferior to corn-soybeans-wheat for soil organic matter maintenance/enhancement, but the difference is likely small, indeed non-existent if wheat straw is marketed off the farm, and cover crops are not used.
  2. The best rotational crop for increasing soil organic matter may well be corn, not wheat. Wheat plus red clover is better, but only if you get decent red clover stands. The worst is soybeans.
  3. Control of soil erosion using no-till soybeans and targeted seeding of winter rye into soybeans, or after soybean harvest, is the most important long-term consideration. I’m not keen on no-till corn for our farm, based on past experiences, but strip tillage would likely be better than our present once-over spring cultivation – for improving soil cover, reducing oxidation of soil organic matter, and reducing springtime earthworm mortality.
  4. Winter rye’s effectiveness in controlling glyphosate-tolerant broadleaf weeds should prove advantageous in years ahead – as the number of these species increases (at present, we have only fleabane) and herbicide-based solutions become less effective.
  5. Higher crop yields – coupled with less tillage – seem the best route for increasing soil organic matter content.
  6. Cover crops such as late-summer/early-autumn-seeded oats should also improve soil organic matter content but very slowly – if this can be done at minimal cost to make it economically justifiable – say, $15/acre, or less.
  7. Cover crop usage will not likely reduce our annual fertilizer bill.
  8. Economically, the weakest part of a corn-soybean rotation may be depressed soybean yields because of too-frequent planting of soybeans.
  9. I emphasize that these conclusions apply only to our farm, with no assumption that they are right for others.

—-

For more than 30 years, our small cash-crop farm near Guelph had a four-crop, five-year rotation of corn, soybeans, corn, white (navy) beans and winter wheat, but then we switched about three years ago to the simpler corn-soybeans. The reasons were several, but the main one was us getting older. We wanted something simpler.

That’s led to two questions:  Are we treating the soil properly? And if not, what can we do about it? That’s what this column’s about.

Soil erosion

The first priority in good soil management is eliminating soil erosion, or at least reducing it to the minimum possible.

We started farming in 1972 with no-till corn but a combination of the inadequate design of early no-till planters, inability to incorporate N and K fertilizer, and unsatisfactory yields meant a change to shallow, once-over springtime cultivation before corn. This is quick and cheap, and does a reasonable job of maintaining soil residue cover, though not as good as with no-tillage. With our no-till soybeans, much of the stalk residue from the previous corn crop remains on the soil surface to retard rainwater flow even after soybean harvest.

Despite the corn-soybean residue cover with no-till soys, I still saw some soil movement in areas of the soybean stubble where the rainfall runoff concentrated in early spring. Winter rye broadcast-seeded in those strips in late August before soybean leaf drop should stop that. Indeed, with that change, soil erosion should actually diminish with our shift to corn-soybeans.

IMG_20180921_112750

Winter rye broadcast seeded into soybeans

Calculations of soil organic matter additions

That brings us to the issue of soil organic matter management, which is far tougher. Organic matter is probably the most important soil-health criterion, as it has such a huge effect on water-holding capacity and drought avoidance. But increasing it is very difficult.

How does corn-soybeans compare to our former four-crop rotation, or to a corn-soybeans-wheat rotation which we could have chosen to use but didn’t?

In seeking answers, I found an excellent analysis done by Kludze et al (Bill Deen’s team) in 2010 at the University of Guelph. (A summary is here.) They used data from the Elora Research Station and across Ontario to calculate the amount of crop organic residue needed to maintain soil organic matter. In Table 1, I’ve used some of their numbers, combined with our 10-year crop-insurance yield records, to compare the three choices for cropping sequence.

Table 1. Calculation of organic matter return to the soil with three cropping sequences on the Daynard farm.

Crop or rotation Grain yield, 10-yr ave. Above-ground residue; assume harvest index of 0.5 Root:shoot ratio (including exudates) Roots and

exudates

Above-ground plus roots and exudates ‘Shoot-equivalent’ organic matter residue (shoot + 2.4 times root+exudates)
bu/acre dry t/ha dry t/ha
Corn (C) 166 8810 0.5 8810 17620 29950
Soybean(S) 49 2870 0.6 3440 6310 11130
Wheat ( W) 83 4780 0.8 7640 12410 23110
W. Beans (B) 36 1990 0.6 2350 4370 7710
Average per year
C-S-C-W-B 5450 6210 11670 20370
C-S 5840 6120 11960 20540
C-S-W 5490 6630 12110 21400
C-S-W (75% straw removed) 4290 6630 10920 20200

Notes: Harvest index = grain dry weight/(grain + above-ground crop residue). Values for harvest index and root:shoot from Kludze et al, 2010. White bean ratios assumed to be the same as for soybeans.

Considering only aboveground crop residues (column three), the corn-soybean rotation is about 9% better than both our former rotation and corn-soybeans-wheat. But when you include root-plus-root exudates (column six), corn-soybeans is slightly worse than corn-soybeans-wheat if wheat straw is not removed. In truth, given the crudeness of the calculations, all three rotations in column six, except for wheat straw removal, are about the same.

Many researchers have found root and root exudates to be a much better contributor to longer-term soil organic matter than above ground residues – 2.4 times better concluded Rasse et al (2004) in an extensive review. When I take this into account and calculate values for what I’ve termed, ‘shoot-equivalent’ organic matter (final column, Table 1), corn-soybeans-wheat turns out to be 4% better than corn-soybeans.

With cover crops

A common practice is to frost-seed red clover into winter wheat fields in March. This rarely worked satisfactorily on our farm, but other farmers have had more success. Another option – indeed, group of options – is to plant a cover crop into the stubble after wheat, into standing soybeans before leaf drop, or after soybean harvest. The calculations are more speculative than for corn, soybeans and wheat, given the huge differences that have been reported for cover crop yields and the sparsity of data on root:shoot ratios.

Using a variety of sources, including this, I’ve made some guesstimates for aboveground cover crop yield and assumed a cover crop root:shoot ratio of 1:1 (Table 2).

Table 2. Calculation of organic matter return to the soil with several cover crop options following winter wheat and soybeans on the Daynard farm, including a 2.4 weighting for roots + exudates.

Rotation Cover crop, above ground ‘Shoot-equivalent’ organic matter residue
dry kg/ha dry kg/ha
C-S-C-W-B 20,370
C-S 20,540
C-S-W 21,400
C-S-W with spring red clover 3000 24,800
C-S-W with cover crop planted in August 2000 23,670
C-S with cover crop 1000 22,240

 

The ‘shoot equivalent’ organic matter addition increases by 11% with cover crop planted after wheat and 8% with cover crop after soybeans. That’s assuming the cover crop grows adequately when planted after wheat or soybeans. That will not always occur and, hence, the 11 and 5% estimates are likely a bit high. Of course, the calculated value is lower if wheat straw is removal.

Rotational effects and cover crop effects on crop yield

The yields, and notably corn yield, shown in Table 1 are based mostly on a history of a four-crop rotation, but they might be different with other rotations.

Corn has yielded about 2% more in corn-corn-soybeans-wheat than in corn-corn-soybeans-soybeans on silt-loam soil at the Elora Research Station. At Ridgetown on clay loam soil, corn has yielded 13% more in corn-soybean-wheat in tilled plots but only 3% with no-tillage (data are in slide 14 here).

Conclusion: our corn would likely yield slightly more, though not dramatically so, with wheat in the rotation.

With wheat plus red clover cover crop, yield increases have been larger at both Elora and Ridgetown.

Data from both Ridgetown and Elora (see slides 23 and 25 here) show a significantly positive effect on soybean yields with the inclusion of wheat in the rotation, even when the soybeans aren’t planted directly after wheat. I don’t know whether this effect is caused by more wheat or less soybeans in the rotation.

Data showing any effect on corn and other field crop yields using cover crops seeded after wheat and soybean harvest are harder to find. Some reports show a yield increase while others show a decline. This report from Iowa State University explores the yield effects in some detail. The safest assumption seems to be no yield effect.

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Poor stand of red clover after seeding into wheat in early spring

Measurements of soil organic matter (SOM)

Any reasonable practice that increases SOM, consistent with the need for the farm to generate reasonable profits, is to be encouraged. Unfortunately that’s hard to do, as discussed by Poulton et al (2018) based on experience of more than 150 years of research at Rothamsted Research, United Kingdom.

Data collected after 20 years of crop rotational research at the Elora Research Station show a 5% (statistically non-significant) higher organic soil carbon content for corn-corn-soybeans-wheat compared to corn-corn-soybeans-soybeans, and another 1% increase if red clover is seeded into wheat. These are for the upper approximately 34 cm of soil depth. (The sampling depth was varied to adjust for differences in bulk density; that adjustment is critical as discussed by Poulton et al).

At Ridgetown, Van Eerd et al (2014) measured a 4% (statistically non-significant; averaged across two tillage regimes) increase in the organic carbon content for the upper 120 cm of soil after 11 years of corn-soybeans-wheat compared to corn-soybeans.

While farm publications often contain testimonials of major increases in soil organic matter occurring after a few years of cover crop use, supportive documentation in scientific literature is sparse.

Poeplau and Don (2014), in a meta-review of published research on effects of cover crops on soil organic carbon, concluded that “The time since introduction of cover crops in crop rotations was linearly correlated with [soil organic carbon] stock change (R2 = 0.19) with an annual change rate of 0.32 + 0.08 [t/ha/year] in a mean soil depth of 22cm.” Unfortunately, their analysis has critical flaws. For one, selected research papers  include several (and including most from Canada) that involve dedicated ‘green manure’ type crops grown for the whole season. Secondly, 70% of the selected studies include no measurement of bulk density; the authors attempt to estimate missing bulk density values using a single negative linear relationship between percent soil organic matter and soil density – for studies in 11 countries on four continents. There are also some weaknesses in statistical analyses. I’m very skeptical about accepting the conclusion from this review.

Calculating changes in SOM

A review of scientific literature suggests it’s difficult to predict changes in SOM content based on annual additions. So many other factors are important.

Kludze et al (2010) assumed, for the Elora Research Station, that 15.1% of crop residues are converted into soil organic matter and that, on average, 2.5% of resident soil organic matter is mineralized (i.e., respired, broken down, lost) per year. They calculated that a minimal annual addition of about 11 t/ha/year of crop residues, roots and root exudates is needed for SOM to remain constant. They assumed the same rate of decomposition for shoot and root residues/exudates.

I did similar calculations for a corn-soybean on our farm, using a range in rates of annual soil OM mineralization and decomposition of added crop residues, and including a 2.4 root/exudate weighting (Table 3).

Table 3. Calculations of soil organic matter losses and gains with various assumptions about rate of soil OM mineralization and annual decomposition of added residues, roots and exudates.

Rate of SOM mineralization (loss) per year (%)
2.0 2.25 2.5
SOM loss, kg/ha/year -1740 -1960 -2180
 
Annual rate of conversion of crop residues, roots, exudates into SOM (%)
10% 12.5% 15%
SOM gain, kg/ha/year +1490 +1860 +2230

Note: It is assumed a corn-soybean rotation adds 20,540 kg/ha of ‘shoot-equivalent’ organic dry matter per year (root and exudates weighted by 2.4), that soil is 4% organic matter in upper 15cm of soil and that soil bulk density is 1.45 g/cm3. Assume the added organic matter is 42% carbon and soil organic matter is 58% carbon.

Table 3 shows that by using different combinations of rates of annual SOM mineralization and addition, I can calculate either an annual gain or loss in SOM for our farm. If I use the Kludze et al choice of 2.5% mineralization and 15% annual addition, our farm soil breaks even.

Importantly, there seems no good reason to believe that our SOM is increasing, and it may be slowly declining.

Note, I am using the range in rates of mineralization and decomposition for a silt loam soil at Elora, which should be applicable to our Guelph Loam soil. These values would be different for a soil higher in clay (slower mineralization or residue decomposition because organic compounds are bonded to clay minerals), and the reverse for a sandy soil. (See Rasse et al.)

Effects of cover crops and higher crop yields

Any increase in annual addition through cover crops or other means will increase the likelihood of a gain in SOM.

Using the same calculation procedure used in Table 3, a cover crop seeded into or after soybean harvest would mean about a 250 kg/ha/year increase in SOM, assuming 15% annual conversion into SOM.

The 250 kg/ha/year equates to an annual gain in percent soil organic matter of about 0.01% with cover crop usage. That’s tiny though it does equate to nearly 0.5% gain over my 47-year farming career.

One other option is increased crop yields. What if our average yields were 20% higher – say to 200 bu/acre for corn and 60 bu/acre with soybeans? That’s a reasonable projection given expected genetic improvement. That would mean about a 620 kg/ha/year increase in SOM using the same assumptions – or about 2.5 times that which might be achieved using cover crops. Of course, it’s reasonable to consider both higher yielding crops and cover crops.

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No-till soybeans

 

What about tillage/no-tillage?

More soil tillage means greater destruction of soil micro-aggregates and faster microbial decay of the organic matter contained within. Organic matter left on the surface with reduced or no tillage also deteriorates more slowly (reference here).

The research data on changes in soil organic matter content with no tillage in Ontario are conflicting. Some comparisons show increased in soil organic matter with no tillage, some the reverse (reference here).

I’m of the opinion that lack of a decrease in soil organic matter may reflect lower crop yields with no-tillage – and with the lower annual organic addition more than offsetting a lower rate of organic matter oxidation in the absence of tillage.

Van Eerd et al (2014) at Ridgetown measured substantially more (>14%) SOM for no-tillage versus annual tillage. Corn generally yielded about 10% more with no-tillage in a corn-soybean rotation.

Dr. Bill Deen (slide 15 here) found corn yield at Elora to be higher with reduced/no tillage when corn followed soybeans, wheat or barley in rotation, but lower for corn after corn or wheat-red clover.

I prefer strip tillage for corn as it provides an easier opportunity for soil-incorporating P and K fertilizer, and perhaps nitrogen too, and counters the tendency for no-tilled soils to warm up more slowly in spring. I wish I knew more about relative effects of no-tillage, strip tillage and shallow-once-over-spring-tillage on earthworm mortality. I suspect that shallow spring tillage is bad, no-tillage is good, and that strip-till is somewhere in between. Some great references are here, here and here.

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View of one of our fields

The ‘sleeper,’ continuous corn

According to Table 1, the best rotation for building soil organic matter would be monoculture corn.

But data from crop rotation studies in Ontario rarely show the highest soil organic matter levels with continuous corn. Perhaps that’s because corn mostly yields less in monoculture than in rotations.

That said, many Ontario farmers have grown corn successfully several years in succession – especially on sandy soils that need all the organic matter they can get.

Christine Brown of the Ontario Ministry of Agriculture, Food and Rural Affairs calculated in a 2017 presentation that a corn-corn-soybean rotation could be more beneficial to SOM than corn-soybeans-wheat. A corn-corn-soybean rotation would also address concerns about too frequent inclusion of soybeans in a corn-soybean rotation – though it would mean a yield reduction for second-year corn.

The calculations above are based on an assumption that all crop organic matter is equivalent for SOM enhancement, with the condition that root+exudate organic matter is 2.4 times more valuable. But farm experience indicates a faster rate of breakdown for some plant material, especially vegetative material that is lusher and with a lower C:N ratio. Highly suberized residue breaks down more slowly. (See Rasse et al for discussion.)

The answers are far from ‘all-in’ on relative merits of different cropping-tillage combinations for SOM preservation and enhancement.

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Crop residues with corn

Other cover crop benefits for our farm?

Deep-rooted cover crops can reduce soil compaction where this has occurred because of heavy field equipment travel, especially on wet soil. That’s not a priority on our farm, to the best of my knowledge, but it may be critical for others.

Water infiltration is a closely related issue with infiltration increasing in response to any technique that slows water flow across the soil surface or opens pores to deeper soil and tile drains below. Maintenance of surface residues with low/no-tillage is very effective. Earthworm-channel formation promotes infiltration as do dead-root channels. I’ve no doubt that cover crops would improve infiltration even more though it is difficult to quantify the benefit.

Weed control is another known benefit. Winter rye has been found very effective in controlling problem weeds like glyphosate-resistant fleabane. Should our existing weed control program prove insufficient for that purpose, rye will be the obvious choice.

A problem comes when the cover is incomplete (eg, red clover into wheat) and weeds grow abundantly in those patches if corrective measures are not taken. There is also need to ensure that the cover crop species itself does not become a weed of concern – and that new weeds aren’t introduced in cheap cover crop seed.

Finally, cover crops have been considered as a means of reducing nitrogen fertilizer need for corn. Research data show, consistently, the benefit of spring-seeded red cover. The same applies to a much lower extent for legume species planted after wheat harvest.

Research commonly shows lower soil nitrate levels in late autumn after cover crop establishment – at least for non-legumes species. However, the same plots often show little difference in soil nitrate levels in spring compared to soils without cover crops. Studies in Ontario have generally shown no reduction in N requirement for the subsequent corn crop after cover crops (legumes excepted, especially red clover). (See here and here, and also unpublished data from Greg Stewart, former OMAFRA corn lead.) Ontario crop consultants generally report no reduction in amount of N recommended for corn following a cover crop, unless the cover crop is a legume – and some consultants recommend more.

Acknowledgments

This column represents the culmination of a personal project of more than a year. I thank the following individuals for providing advice, insight and information (though none should be blamed for what’s written above): Drs. Laura Van Eerd, Bill Deen and Dave Hooker, and Ken Janovicek, University of Guelph; Andrew McGuire, Washington State University; Anne Verhallen, Christine Brown, Sebastian Belliard, Jake Munroe and Ian McDonald, Ontario Ministry of Agriculture, Food and Rural Affairs; Dr. Angela Straathof and Harold Rudy, Ontario Soil and Crop Improvement Association; Patrick Lynch, Peter Johnson (Real Agriculture), Greg Stewart (Maizex Seeds), Ken Nixon and several Ontario crop consultants (whom, for fear of missing someone, I’ll not list here); the many knowledgeable and experienced farmers I’ve interacted with on Twitter; and finally, thanks to you – all five of you – who have read this far!