Stover harvest increases yield stability in continuous corn systems

Abstract

Studying the effects of continuous corn (Zea mays L.) stover removal on its productivity across management systems is key to understanding how crops respond to varying climatic conditions. In the context of increasing climate variability, studying corn yield stability can serve as an indicator of resilience to changing climate. The objectives of this study were to (i) evaluate yield stability under varying levels of stover harvest and (ii) determine the effects of thermal time and precipitation on yield stability in continuous corn systems. A long-term experiment in a continuous corn system with different levels of stover harvest (0%, ∼50%, and ∼90% of aboveground residue), tillage systems, and biochar rates was carried out. Corn yield and yield stability were evaluated. Multiple regression models were developed to determine which factors best explained treatment differences. Both corn yield and yield stability were highest with 50%–90% stover harvest. Yields increased 6%–15% when stover was harvested. High rates of biochar offset the negative impacts of stover retention on yield stability. Tillage did not affect yield stability, but yields were greater under chisel plow than no-tillage. Precipitation explained 43%–49% of yield variability in all treatments. Conversely, thermal time and yield were only correlated in treatments without residue removal. Our results show that yield stability in continuous corn systems is more heavily influenced by stover harvest than biochar application or tillage. Thus, despite other potential environmental drawbacks of continuous corn systems, incorporating stover harvest may improve resilience to projected weather fluctuations.