Single and multispecies cover crop effects on corn production and economic returns

Authors: SINGH, BHUPINDER - Texas A&M Agrilife; KAUR, GURPREET - University Of Missouri; SINGH, GURBIR - University Of Missouri; DHILLON, JAGMANDEEP - Mississippi State University; QUINTANA-ASHWELL, NICOLAS - Mississippi State University

Submitted to: Journal of Contemporary Water Research & Education
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/21/2023
Publication Date: 8/7/2023
Citation: Singh, B., Kaur, G., Singh, G., Dhillon, J., Quintana-Ashwell, N. 2023. Single and multispecies cover crop effects on corn production and economic returns. Journal of Contemporary Water Research & Education. 178:71-89.

Interpretive Summary: The use of cover crops (CC) has gained popularity for use in continuous corn production systems. The CC provided benefits such as fixing nitrogen (N) in the soil. However the ability of a CC to properly be established and improve N in the soil following the cash crop season is dependent on both the species of the CC and the growing environment. A study was carried out in three diverse environments to determine growth characteristics of nine CC treatments including single species and mixes of grasses, legumes, and brassica. The impact of the CC treatments on the following season's corn crop was compared to a control treatment of no cover crop (noCC). The various CC treatments varied significantly in the development of above-ground biomass, plant tissue Carbon (C) and N concentrations, C/N ratio, and total N uptake (TNU). In single species treatments the grasses had the highest biomass and C/N ratio while legumes had the highest concentrations of N and TNU. The C/N ratios for each CC treatment varied across all three environments. The CC belonging to the same species exhibited different characteristics based on the environment. Likewise, the expected returns on the investment of CC varied, particularly for the CC mixes. This study demonstrated species-specific functionality of CC in continuous corn under variable environmental conditions and indicates that further study is needed to explore high diversity mixes of CC that may improve performance across environments.

Technical Abstract: The adoption of cover crops (CCs) has gained popularity in the continuous corn (Zea mays L.) production system due to their multiple benefits including scavenging or fixing nitrogen (N) in the soil. However, a CC’s ability to develop early cover, scavenge N, and provide N to the following cash crop is species-dependent and affected by environment. A field study was conducted in three diverse environments to determine growth characteristics of nine CC treatments (i.e., monocultures or mixes of grasses, legumes,and brassica), and their effect on the following corn crop was compared to no cover crop treatment (noCC).Cover crops significantly differed for above-ground biomass, plant tissue carbon (C) and N concentrations,carbon to nitrogen ratio (C/N), and total N uptake (TNU). Among monocultures, grasses had the highest biomass and C/N ratio, and legumes had the highest N concentrations and TNU. Corn grain yield was highest following radish, whereas lowest corn yield was found following cereal rye + crimson clover mix in environment 1. Cover crops varied for C/N ratios in all three environments, but only affected corn plant height (PH) and grain yield in one environment. Cover crops belonging to the same species also exhibit different responses for characteristics measured, depending upon the environment. The expected returns were also variable, especially in CC mixes. The study provides valuable information on the species-specific functionality of CCs in continuous corn under variable environmental conditions. The information will benefit future studies to explore a high diversity mixture of CCs that may outperform across all three environments.