Cover crop performance under a changing climate in continuous corn system over Nebraska.

Area of Science:

• Agricultural Science
• Agronomy
• Climate Science

Background:

• Continuous corn systems face challenges from climate change, including temperature increases and precipitation variability.
• Cover crops (CC) offer potential agroecosystem benefits, but their performance under changing climate conditions requires further investigation.

Purpose of the Study:

• To assess the long-term effects of cereal rye cover crops on no-till continuous corn yield and soil properties.
• To evaluate CC performance under historical and projected climate change scenarios in eastern Nebraska.

Main Methods:

• Utilized the Decision Support System for Agrotechnology Transfer (DSSAT) model for long-term simulations.
• Employed historical weather data (1991-2020) and projected climate data (2041-2070) from the Canadian Earth System Model 2 under RCP4.5 and RCP8.5 pathways.

Main Results:

• Cover crops had nonsignificant impacts on corn yield under both historical and projected climate conditions.
• Climate change favored CC growth, increasing biomass and reducing nitrogen (N) leaching by an average of 60% under future scenarios.
• CC reduced total and plant-available water in the soil profile but decreased seasonal surface runoff/soil evaporation and increased soil organic carbon buildup.

Conclusions:

• Cereal rye cover crops show promise for mitigating climate change impacts in continuous corn systems by improving soil properties, despite not directly increasing yield.
• The study highlights the need for wider scaling of cover crop species and locations to understand their full potential in adaptive agriculture.