Conservation agriculture may improve plant and human health by bolstering mycorrhizal networks

Authors: Carrara, Joseph; BEELMAN, ROBERT - Pennsylvania State University; DUIKER, SJOERD - Pennsylvania State University; Heller, Wade

Submitted to: Soil and Tillage Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/26/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Farm management practices which reduce soil disturbance (e.g. "no till" agriculture) have well known benefits of reducing soil erosion and enhancing soil health, but the relationship between tillage intensity on crop yield, plant nutrient uptake, crop nutritional quality, and ultimately human health are not well understood. Here, we utilized plots from a long-term (40+ year) agricultural tillage intensity trial to investigate the impact of crop nutritional quality in two crops (soybean and wheat) from three levels of varying tillage intensity, and simultaneously analyzed the impact of tillage on root colonization by beneficial symbiotic arbuscular mycorrhizal fungi. Overall, we found that tillage negatively affected mycorrhizal colonization in both crops, and that accumulation of the fungal-derived antioxidant ergothioneine (ERGO) was also reduced by tillage. We found that high tillage intensity reduced the ERGO concentration of wheat grain by about half and reduced the total ERGO yield per plot of both wheat and soybeans by ~30%. As ERGO deficiency has been associated with a number of inflammatory diseases and diseases of ageing in humans, its fortification in crops through agricultural management practices has far reaching public health benefits.

Technical Abstract: Many farmers have adopted reduced tillage management practices. While the effectiveness of these practices at reducing soil erosion and enhancing soil health is well documented, the impact of reduced tillage on plant nutritional quality is not well understood and the relationship between tillage intensity and crop yield is inconsistent. Current interest in the role of the fungal derived antioxidant ergothioneine (ERGO) in human health has driven efforts to understand the influence of different crop management practices on the transfer of ERGO from soil to plants and ultimately to human consumption. Recent work in a long-term tillage trial has shown an inverse relationship between tillage intensity and plant ERGO concentration in corn, oats, and soybeans. Further, pot studies have shown that percent mycorrhizal colonization is positively correlated with plant ERGO and mineral nutrient concentration. Therefore, we hypothesized that tillage reduces the ERGO concentration of plants by disrupting mycorrhizal mycelial networks which likely play a role in plant ERGO uptake from soils. To test this hypothesis, we sampled roots and plant tissue from soybeans (Glycine max) and wheat (Triticum aestivum) in a long-term (40+ year) side-by-side tillage trial and examined the extent to which moldboard plow (high intensity tillage), chisel/disk (intermediate tillage), and no-till (minimal disturbance) practices affected mycorrhizal colonization, ERGO concentration, mineral nutrient concentration, and yield. We found that high tillage intensity reduced the ERGO concentration of wheat grain by about half and reduced the total ERGO yield per plot of both wheat and soybeans by ~30%. Further, the ERGO concentration of wheat was positively correlated with percent mycorrhizal colonization. These results demonstrate a possible link between soil health and human health through positive mycorrhizal influence on plant ERGO uptake.