Reported declines in the nutrient density of crops are typically attributed to crop breeders having focused almost exclusively on increasing yields. However, studies demonstrating that fertilization regimes and soil life affect mineral uptake by crops suggest that conventional farming practices of intensive tillage, nitrogen fertilization, and synthetic pesticide applications may have contributed to declining nutrient density through disrupting crop symbioses with soil life. While a number of previous assessments compared differences in the nutritional quality of foods grown with conventional and organic production practices, few have considered directly the influence of soil health—as reflected in soil organic matter and soil life—on nutrient density.
Although proponents of farming practices that rebuild soil organic matter and soil health (which we collectively term “regenerative”) contend that such practices result in more nutrient-dense food, such claims remain little tested.
New research led by geomorphologist David Montgomery of the University of Washington compares the effect of regenerative farming on soil health and crop nutrient density from a cohort of paired farm trials across the United States. Along with evidence from several other paired farm and plot studies this comparison indicates that regenerative agricultural practices employing no-till, cover crops, and diverse crop rotations enhance soil health and the micronutrient and phytochemical density of various crops.
It also compares the fatty-acid profile of beef and pork raised on one of the regenerative farms to a regional health-promoting brand and conventionally raised meat purchased at a local grocery store. The results suggest that farming practices that affect soil organic matter and microbial communities are under-appreciated influences on crop nutrient density, particularly for micronutrients and phytochemicals relevant to plant health and chronic disease prevention in humans. These preliminary results point to soil health as a more pertinent metric for assessing the impact of farming practices on the nutrient composition of crops than the usual distinction of organic and conventional practices.