Soil and the health of agricultural systems

Last week I was encouraged to see an article on CBC that highlighted recent research into organic farming by Agriculture Canada here on PEI. Of particular interest was the emphasis on cover crops and getting legumes into the rotation. Regardless of whether one is practicing organic agriculture or not, the emphasis on practices and crops that build soil health is important. I am reminded of the very readable recent book by David R. Montgomery — “Growing a Revolution: Bringing Our Soil Back to Life“. Montgomery outlines how the same principles apply around the world: the combination of no-till planting, cover crops, and diverse crop rotations provides the essential recipe to rebuild soil organic matter. In other words, practices based on the principles of conservation agriculture help restore soil health and productivity. He visits farmers around the world who have found it possible and profitable to adopt practices that are good for farmers AND good for the environment.

A few days later, I came across this news item on recent research about the impact of agriculture on soil carbon and carbon emissions ( The news item is based on a recent article in PNAS: “Soil carbon debt of 12,000 years of human land use” by Jonathan Sanderman, Tomislav Hengl, and Gregory J. Fiske (PNAS 2017 ; published ahead of print August 21, 2017, doi:10.1073/pnas.1706103114). Here are links to the abstract (…/early/2017/08/15/1706103114.abstract), Full Text (…/early/2017/08/15/1706103114.full.pdf) and Supporting Information (…/15/1706103114/suppl/DCSupplemental). In his book, Montgomery outlines principles and gives examples of farmers who are reversing this trend by rebuilding soil carbon through the adoption of appropriate climate-resilient conservation agriculture practices.

Adapting to a changing climate: It’s not always new technology we need

Over the past few years, I have been part of many discussions about agricultural production and what to do about the challenges faced by family farmers in the developing world. In those conversations about food security, improving agricultural production and/or adapting to climate change, there seems to be an implicit (if not explicit) assumption that what is needed is new technology. This seems to ignore that fact that there are often existing practices which would result in improvements to the amount and reliability of agricultural production — practices that, for a variety of reasons, remain largely unadopted. Various soil and water conservation (S&WC) practices are a case in point. Another assumption is that production is limited by the genetic potential of the seed, when often what is really limiting for crop production (both yield and stability of the yield) is the health of the soil — one of the main components of the agro-ecosystem. Making a concerted effort to reverse the trend towards more and more degraded soils through the adoption of good S&WC practices can go a long way to improving soil fertility and water holding capacity — resulting in improved resilience, productivity and sustainability in a fairly short time.