Is Corn/Soybean Really the Most Economic Crop Rotation for Farmers?.

The Elora long term crop rotation trial (est. 1980) has 8 rotation treatments: continuous corn, continuous alfalfa, and six treatments of two years of corn followed by two years of rotation crop(s) consisting of soybeans, barley, winter wheat, oats, alfalfa, or red clover. All rotation treatments are split into no-till and conventional till sub-plots. This trial consistently demonstrates soil health, agronomic, and environmental benefits of rotation diversity. In spite of growing evidence of rotation diversity benefit, and the linkage of rotation diversity with effective cover crop use and reduced/no-till tillage, farmers across Ontario and the Northern Corn Belt are increasingly moving towards simple corn/soybean rotations, presumably because simple rotations are perceived as more profitable. Using data from the Elora long term rotation trial, a partial budget analysis was conducted to determine whether the agronomic benefits associated with rotation diversity provide sufficient economic incentives to encourage rotation diversity. While a number of benefits (eg. yield enhancement) can readily be quantified, other benefits (eg. drought resiliency, reduction in nutrient, tillage and energy requirements, improved resistance weed management…) are much more difficult to estimate. Whether these economic incentives are increasing over time and whether they are expected to further increase due to future effects of changing climate, emerging biomass industries, and intensification of production systems is also considered.