Cotton Engaged in High-Biomass Rye Cover Cropping Systems: Assessing Water Use Efficiency with Plant-Based Irrigation Scheduling.

Current research suggests the best tool to manage for glyphosate-resistant Palmer amaranth is planting a heavy rye cover crop and then rolling it over before planting operations have begun. This management tool has been shown to a viable alternative to hand weeding for dealing with these persistent and vigorous weeds. However, cover crops are also considered a tool for reducing soil water losses as well. The goal of this project was to evaluate the effects of a heavy rye cover crop on cotton physiology and yield. Treatments were implemented in 2014 and 2015 at the University of Georgia's Lang-Rigdon research farm under a lateral irrigation system with valves on the nozzle drops that allowed irrigation to be turned on and off. The treatments were two rye treatments: Heavy rye or conventional tillage, and three irrigation triggers: -0.4 MPa, -0.5 MPa, and -0.7 MPa predawn water potential measured twice per week. Infield physiological data collection throughout the growing season was collected biweekly.