Stover Management and Nitrogen Fertilization Effects on Corn Production

The incorporation of crop stover into the soil improves soil fertility and crop productivity by increasing C sequestration and reducing the emission of greenhouse gases among other parameters. Interactions between crop stover management and N fertilization could help to improve C sequestration while increasing productivity. The objective of this study was to evaluate the impact of incorporating or removing corn (Zea mays L.) stover, in combination with different N fertilization rates (0, 100, 200, and 300 kg N ha(-1)), on corn production, soil organic carbon (SOC), and soil mineral nitrogen (SMN) in high production areas. We performed two field experiments (Exp. 1 and 2) for 3 yr under sprinkler irrigation. Over the duration of the experiment (short-term period), stover management did not affect corn production or SMN levels, while high average grain yields were achieved (16-20 Mg ha(-1)) when N was applied. After 3 yr, removing the stover reduced SOC levels by approximately 0.82 and 1.06 g C m(-2) (0-30-cm depth) in 2012 in Exp. 1 and 2, respectively. The amounts of corn stover incorporated were higher than 16 Mg ha(-1) yr(-1) of dry matter. Our data suggest that returning stover to the soil has a positive short-term impact on soil quality without grain yield penalties. Although selling the stover provides a short-term economic advantage, continuous stover removal may cause significant soil degradation in the future.