There is much to applaud about a new report by the Environmental Commissioner of Ontario (ECO) called “Putting Soil Health First.” (The report is available here; a brief summary by John Greig can be found here.)
The report emphasizes the need to improve soil quality and reverse a long-term downward trend in soil organic matter levels in Ontario soils. The writer of the report demonstrates a good understanding of soil biology and its relationship to agronomic performance, and rightly criticizes an agricultural industry which has not placed sufficient priority on maintenance and improvement of soil quality. The report also acknowledges the success of this industry in producing an ever-increasing abundance of food at a declining real cost to consumers. Ontario farmers and others interested in this subject should take the half hour or so required for a read.
At the same time, I have major unease with the report. Too often, it seems as if the commissioner and/or her writers have used the issue of soil quality for another agenda: to attack non-organic agricultural practices which have little effect on soil quality and which in fact can and do make a positive contribution to soil organic matter enhancement. I’ll briefly highlight some examples below.
The report contains a strong condemnation of synthetic pesticides and fertilizer, stating that they are partially responsible for declines in soil organic matter while providing scant evidence that this is true. The report contains one small section called “How the Inappropriate or Over Use of Synthetic Inputs Can Impair the Natural System,” but even that section seems to rely excessively on anecdotal information and opinions, suggesting that temporal impairment of microbial activity at time of application means long-term, measurable changes in soil organic content. In addition, the report totally ignores good logic and evidence for the reverse – for example, the increase in crop organic matter production including additions to the soil stimulated by good fertility and by the control of leaf/plant-killing diseases and insects.
The report rightly points out how tillage encourages soil organic matter oxidation, but ignores the benefit of pesticides (herbicides) in reducing/eliminating the need for tillage. This is a huge oversight in my view.
The report seems also to perpetuate the myth than better soil structure means fewer weeds – hence, less need for pesticides. Crop plants grow better in better structured soils, it’s true, but so too do many weeds. Indeed, the main reason why these plants are serious “weeds” is that they prosper in the same ecological niche as the crops which they infest.
The commissioner also makes the strange suggestion that climate change will increase the prevalence of herbicide-resistant weeds. (The reference cited by the commissioner in support of this statement makes no such claim.)
Perhaps to place fertilizers in a negative light, the report provides an extensive report of one farm in North Dakota which reports good yields with minimal fertilizer usage. There is no mention of the decades of extensive publicly-funded research which has been done on soil fertility needs in Ontario and adjacent states. Further, discussion with organic farmers in Ontario reveals that the provision of an adequate supply of P fertilizer – and in some cases N too, for example in meeting the needs of winter wheat in May-June – represents one of their biggest agronomic challenges.
The report rightly condemns the unsustainably high loss of phosphate from farm soils and the importance of minimizing surface water runoff. But there is no mention of the significance of losses through tile drainage, nor of informed suggestions (albeit controversial) that this loss may be enhanced by deep, well-developed soil pores associated with no tillage.
The report condemns the use of summer fallowing in Ontario – which begs the question: does summer fallowing actually exist in Ontario (notwithstanding those instances where excessive spring rainfall prevents crop planting)?
The report rightly emphasizes the linkage between animal agriculture – or more specifically, ruminant animal agriculture – and perennial forage production. But it dodges the reality that this may also mean increased greenhouse gas emissions (from rumen methane emissions) to offset, at least in part, the resulting increase in soil organic matter associated with perennial forage production. The report also makes two really strange statements about animal agriculture – one being that livestock farms are not closely connected to crop production. (One wonders whether the commissioner or her writers are aware of Ontario’s “nutrient management” requirements for livestock farms.) The other is the implication that manure storage – with associated emissions of methane – is not needed when farmers apply manure to their own fields. This seems to ignore the evils of applying manure to soil in winter and ministerial guidelines on lengths of manure storage required (sometimes for a year or more).
I have always been of the opinion that while composting is beneficial in reducing manure volume/weight and in producing stable organic matter, it also represents a loss of about half of the carbon content of the original organic material; organic matter converted into carbon dioxide in the compost pile would otherwise be used to feed soil organisms if applied directly to soil. The report makes a feeble attempt to argue that composting is better but its scientific support and rationale for saying so is very limited. The argument that composting reduces nutrient loss in the field (instead, the nutrients leach under the compost pile!) is equally flimsy.
The report features one organic farm in New York State which produces yields of 200 bu/acre of corn and obviously does a good job. (It does not state whether this is the harvested production from one year or two years of cropping; organic farmers sometimes don’t harvest a previous year’s legume forage to maximize soil N supply for the corn crop to follow.) However, notably missing is a reference to extensive multi-farm data (crop insurance in Ontario; USDA in the US) showing that organic crops, on average, yield about 2/3 of their non-organic counterpart. On average, it take 3 acres of organic land to produce as much as 2 acres of non, and that has obvious implications on the total amount of land needed – not to mention the cost to consumers, and the environmental cost – to meet Ontario’s food needs.
The report features the Belan farm near Inwood, and with good reason. I too am a fan of the practices of this innovative farm and their 25 years of no tillage. The report notes the Belan claim that their soil organic matter has increased from 2 to 5% because of no tillage, but also notes that this is only for the upper 15 cm of soil. I drew that conclusion once myself – that no till was having a huge effect on soil organic matter in my plots at Elora. But then Dr. Tony Vyn and Dr. Bev Kay measured soil organic matter at deeper depths and found the reverse down there. No tillage generally means a change in OM distribution rather than an increase in soil OM per se in Ontario and eastern Canada – at least in most test results (as an exception, Dr. Laura Van Eerd and colleagues have measured higher OM in no-till soils to depth, but only in certain crop rotations, at Ridgetown.) With respect to the Belan farm data, the report says “the reader should note that the ECO is not suggesting that the Belan’s situation should be taken as definitive from a soil-carbon sequestration perspective.” But then the report goes on to do the exact opposite with some extensive calculations for all of Ontario based on one farm’s numbers. There is certainly no qualification in the summary statement: “the Belans have increased the carbon levels in their soils by three per cent, which means that they have sequestered about 48,000 tonnes of CO2.” Once again, no slam is intended by me to the Belans. This criticism is about what the commissioner did with their information.
Indeed, almost totally missing in this report is recognition of the extensive research which has been done by public researchers at the University of Guelph (including Ridgetown) and Agriculture and Agri-Food Canada. The emphasis is instead on anecdotal reports from a few individual farms. The commissioner is very critical of actions by the Ontario Ministry of Agriculture, Food and Rural Affairs with respect to soil quality, but does not appear to be aware of most of what the ministry and its staff actually do – including core funding of soil management research at Guelph and Ridgetown. I am also bothered by the emphasis on popular press reports in the reference material, with relatively few references to formal research publications. There are also many places where the commissioner seems to draw unqualified conclusions based on a single reference (often anecdotal).
Finally, I am puzzled with the occasional references in the report suggesting that better soil stewardship was practiced in days past. Statements to the effect that earlier farmers did not leave soil bare in winter are simply false. In fact, one of the first traditional operations immediately after wheat or spring-grain harvest was usually mold-board plowing– and condemned was the farmer who left any crop residue showing on the soil surface after plowing was completed.
The same applies for crop rotations. Forty years ago, many Ontario farmers grew only corn, and 160 years ago it was continuous wheat. Even my father in the 1950s grew only two crops in rotation – perennial forages and spring grain. Soil quality might benefit from more crops in the rotation, or it might not:it depends on the crops. Many alternative crops don’t produce a lot of crop residues and, hence, soil organic matter – e.g., beans, vegetable crops. We’ve already talked about perennial forages, an excellent addition to your crop rotation – IF you have a market.
My list of faults with the commissioner’s report has not been exhausted. But I expect that my reader’s attention span has. So I’ll close here.“Putting Soil Health First” is a useful report, but it could have been so much better it the commissioner and/or her writers had focused on soil health alone and avoided the temptation to promote another agenda. Sadly, I’ll now be reading with skepticism any other reports from the ECO. Will they be equally distorted? Will they too have another unstated agenda?