No-till imparts yield stability and greater cumulative yield under variable weather conditions in the southeastern USA piedmont

With projected increases in global temperatures and changes in regional climate, understanding the impact of soil management choices on yield stability is critical for farmer decision-making and agricultural resiliency. Notill and conservation tillage have had variable yield effects depending on crop and location, requiring long-term system-specific studies to gauge potential benefits. Yield and weather data from a 28-year tillage study in the southeastern U.S. piedmont region were analyzed to determine the effect of various conservation tillage practices on maize and soybean productivity and stability under a variety of growth conditions. Growing seasons were grouped by soil moisture and temperature during crop growth stages, and mean crop yields and yield coefficient of variation for the tillage treatments were calculated within the year clusters. Probability density estimates were also used to predict the likelihood of obtaining yields at low and high percentiles. No-till and conservation tillage increased maize yields 42-93% and no-till decreased coefficient of variation of maize yields when soil moisture was low by 10-32%, but had a less pronounced effect on soybean yields. However, the probability of reaching the 90th yield percentile was greater in no-till than conventional tillage in both maize and soybean, by 15% and 10%, respectively. Yield differentiation occurred early in the study, before there was likely substantial differentiation of soil properties from tillage treatments. Previous reports from the site have likewise indicated little differentiation in soil health between tillage systems over the life of the study. Results suggest that surface residue management may be an important driver of system performance, possibly more so than overall soil health.

Automated summary

Understanding the impact of soil management choices on yield stability is crucial for agricultural resiliency in the face of global temperature increases and regional climate changes. Long-term studies are needed to assess the potential benefits of no-till and conservation tillage, as their effects on crop yields vary depending on the crop and location. Findings from a 28-year tillage study in the southeastern U.S. piedmont region suggest that surface residue management may be more important than overall soil health in determining system performance.