Paul Smith, Sustainable Agriculture Consultant

Quantifying soil health on agricultural lands has become a global priority, yet it remains unclear how much management practices have improved soil functioning on commercial farms, or how much potential for improvement remains. Reference-based benchmarking, by comparing row-cropped soils to undisturbed perennial soils, offers one approach for addressing this. Our objectives were to (1) determine the maximum soil health potential for soils under row crop production, (2) quantify the effects of management practices, and (3) assess progress toward soil health potential under improved management. We sampled 262 soils from the Greater Golden Horseshoe region in Ontario, Canada: 160 from grains and oilseeds, and 102 from perennials undisturbed by cultivation (> 10 years) to represent references. Soil measurements included texture, pH, organic carbon, aggregate stability, and potentially mineralizable carbon. Multiple linear regression was used to evaluate effects of management and inherent soil properties on soil health indicators, and logistic regression was used to estimate the probability of reaching a hypothetical goal relative to the potential for each indicator. Decreased soil disturbance, cover crops, and presence of winter wheat (Triticum aestivum L.) in rotation were the factors that improved aggregate stability. Manure additions and cover crops were the factors that improved potentially mineralizable carbon. The probability of approaching a goal of 75% of the reference aggregate stability value increased from 0.36 (conventional) to 0.76 (no-till and cover crops). By comparing management with respect to soil, our approach quantifies progress achieved by farmers and the potential for improvement to enable soil health interpretations.

The Greenbelt Foundation, in partnership with the Soil Health Institute, has released a recommendations report for soil health assessment frameworks. Using

Field sampling at 264 locations across the Greater Golden Horseshoe shows that soil-health practices deliver consistent benefits. Compared with baseline management, sites using reduced tillage, cover crops, and living roots achieved better aggregate stability, higher organic matter, and greater available water. Reference sites with very little disturbance performed best, setting an aspirational benchmark. These results link everyday practices to outcomes that matter, including fewer problems in wet springs, better drought tolerance, and more reliable yields. The report translates indicators into clear guidance and highlights actions farmers can take now to strengthen soil function and manage risk.