Impacts of Winter Cover Crops on Soil Properties, Root Development, and Crop Performance in Southeastern Cropping Systems.

Abstract

Cover crops are increasingly recognized as a key management strategy to improve soil health and enhance sustainability in southeastern U.S. cropping systems. However, their effects on soil-plant interactions and subsequent crop performance are not fully understood. This study evaluated the impact of different winter cover crops on soil physical properties, root development, plant physiological responses, and yield in cotton (Gossypium hirsutum L.), soybean (Glycine max (L.) Merr.), and peanut (Arachis hypogaea L.) systems. A four-year field experiment was conducted using a randomized complete block design with four winter cover crop treatments: crimson clover (Trifolium incarnatum L.), rye (Secale cereale L.), and forage radish (Raphanus sativus L.), and fallow, under irrigated and rainfed conditions at two locations in Alabama. Measurements included soil penetration resistance, gravimetric soil moisture, root architectural traits, gas exchange parameters, and crop yield. In cotton systems, cover crops influenced soil physical conditions, particularly soil strength, and affected root development. Rye frequently reduced soil strength and promoted greater cotton root growth under certain conditions, although yield responses were generally limited. In soybean and peanut systems, cover crops modified soil moisture dynamics and influenced root traits and physiological responses, including stomatal conductance. Soybean responses were more closely associated with changes in soil water availability and physiological activity, whereas peanut responses were primarily linked to root system development and soil physical conditions. Overall, this study demonstrated that cover crop effects are cash crop-specific and depend on their influence on soil physical and hydrological processes. This is the first study that demonstrates that cover crops can influence root development of the following cash crop. These findings highlight the importance of selecting cover crop species based on functional traits that best align with the requirements of the subsequent cash crop, contributing to improved soil management and resilience in southeastern cropping systems.