Soil health management practices and crop productivity

Abstract

Globally, food systems face multiple challenges, including minimizing environmental impacts, adapting to a changing climate, increasing yields, and maintaining and/or increasing crop nutritional quality. Management techniques that focus on soil health (SH) are promising solutions to mitigate some environmental impacts and may increase economic returns. However, claims that SH increases will concurrently increase crop quality and productivity merit careful examination. Factors beyond SH metrics determine crop nutritional quality. Yield outcomes of SH management are of significance, as there are concerns that yield increases are insufficient to meet future food demands. While SH frameworks are comparatively recent initiatives, there are thousands of published conservation agriculture studies that examine yield outcomes with cover crops, no‐till, and rotation. This literature indicates that SH practices can also have neutral or negative yield impacts—only in select systems have consistent yield increases been realized, highlighting the need for language clarification and improvements in mechanistic understanding of regional‐scale yield impacts.

Relating indicators to soil health functions in conventional and organic Mediterranean cropping systems

“…The negative relationships observed between yields and the organic C and biological process indicators contrast with the observations of Culman et al (2013), that labile C and N fractions had a significant positive relationship with rainfed corn yields in Michigan. However, they are in line with several recent studies which suggest that most soil health assessment strategies may only be related to crop yield if soil water availability or fertility are the limiting factors (Leytem et al, 2020;Miner et al, 2020;Zebarth et al, 2019). Healthy soils can benefit crops by supplying nutrients and improving water infiltration and retention (Stewart et al, 2018).…”

“…Healthy soils can benefit crops by supplying nutrients and improving water infiltration and retention (Stewart et al, 2018). However, in fertilized and irrigated cropping systems, these benefits often do not result in higher yields (Miner et al, 2020). A comparison of the inputs (e.g., fertilizers, pesticides, and irrigation water) needed to achieve yields comparable with fields with a lower soil health score may be a useful approach for evaluating the impacts of soil health on crop performance.…”

“…For example, if 2018-2019 ORG tomato yields were low because soilborne pathogen populations had built up over time in the ORG soils, yield resilience could be expected to continue to decline. Including yield resilience metrics in a soil health assessment may be useful for identifying crop-specific effects of management on soil health when combined with other measures (Miner et al, 2020;Seufert & Ramankutty, 2017).…”

“…However, there is increasing evidence that these indicators need to be regionally selected and calibrated (Caudle et al, 2020;Chahal & van Eerd, 2019;Roper et al, 2017;Zuber et al, 2020). Additionally, the common assumption that improvements in soil health will support higher crop yields or allow reduced inputs may also be management and region specific (Miner et al, 2020). In particular, benefits may depend on the degree to which water and fertility are the yield-limiting factors (Leytem et al, 2020).…”

“…In particular, benefits may depend on the degree to which water and fertility are the yield-limiting factors (Leytem et al, 2020). The benefits of "soil health building practices" to crop yields therefore must be assessed in specific contexts (Miner et al, 2020).…”