Geographical Variation in Cover Crop Management and Outcomes in Continuous Corn Farming System in Nebraska

Authors: SHIFERAW, ANDUALEM - University Of Nebraska; Birru, Girma; TADESSE, TSEGAYE - University Of Nebraska; Jin, Virginia; Schmer, Marty; AWADA, TALA - University Of Nebraska; WARDLOW, BRIAN - University Of Nebraska; Freidenreich, Ariel; IQBAL, JAVED - University Of Nebraska

Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/10/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: Cover crops, which are essential for enhancing soil health and providing various ecological benefits, exhibit varying effectiveness based on local environmental conditions including climate, soil types, and management practices. This study aimed to evaluate the spatial variability in cover crop management outcomes and its implications for corn yield in Nebraska. Specifically, the analysis focused on three key management aspects: seeding rate, termination-to-corn planting intervals, and termination timing. By integrating field simulations with site-specific environmental conditions, the study provides actionable insights for optimizing cover crop practices under diverse agroecosystems. The examination of cover crop management in Nebraska reveals significant insights into spatial variability and its implications for agricultural productivity. The findings underscore the complex interactions between cover crop management decisions, local climatic and soil conditions, and their impact on subsequent corn yield. Across all sites, corn yield demonstrated resilience to cover crop adoption. This stability highlights the adaptability of corn production under diverse management practices, though site-specific yield penalties and improvements reflect the nuanced influence of local environmental conditions. This finding emphasizes the importance of tailoring seeding rates to specific agronomic and economic objectives. Termination timing was another critical factor influencing management outcomes. Delayed termination dates maximized cover crop biomass. Overall, the study highlights the complexity of cover crop management and the necessity of integrating site-specific climatic and soil information into decision-making. By addressing the interplay between agronomic objectives, environmental benefits, and operational constraints, this research provides a framework for farmers and land managers to make informed decisions that optimize both productivity and sustainability in agricultural systems.

Technical Abstract: Cover crops (CC) are widely recognized for their potential to improve soil health, mitigate erosion, and enhance nutrient cycling. However, the outcomes of cover crop management can vary significantly based on site-specific biophysical conditions and agro-nomic management practices. This study examines the spatial variability in cover crop management outcomes across Nebraska, focusing on three critical aspects: seeding rate, termination timing, and termination-to-corn planting intervals. Using field simulations and site-specific climatic data, we evaluated the impacts of these management decisions on cover crop biomass, growth stages, and subsequent corn yield for seven sites across the state. The results revealed that corn yield was generally resilient to cover crop adoption, with no statistically significant (p<0.05) differences observed between CC and no cover crop (NCC) systems across all sites. However, site-specific responses highlighted nuanced trade-offs. For instance, drier and warmer sites, such as North Platte, experienced minor yield reductions due to competition for soil moisture. In contrast, sites like Alliance and Valentine benefited from moisture retention and yield stability under cover crop systems. Higher seeding rates consistently enhanced cover crop biomass but had minimal impact on corn yield, emphasizing the need to balance biomass-related benefits with economic considerations. Termination timing significantly influenced cover crop biomass and growth stages, with delayed termination maximizing biomass but increasing risks of advanced growth stages and herbicide inefficacy. This study underscores the importance of tailoring cover crop management strategies to local environmental conditions and agronomic goals.