LAUSR

Simple Summary Cover crops such as rye and wheat are widely used to protect the soil, save water, and reduce weeds in farming systems. While these benefits are clear, the remains of these plants left in the soil can also release natural chemicals that may slow down the growth of the next crop. Cotton is an important crop grown after cover crops in many regions, and farmers are often concerned that too much residue could reduce cotton yield. In this study, we grew cotton in greenhouse conditions and compared the effects of rye and wheat residues with those of a purified natural chemical produced by these plants. We found that moderate amounts of rye sometimes improved cotton germination, but high levels of residue greatly reduced germination and growth. Wheat had weaker effects, and the purified chemical alone caused only short-term changes. Our results show that the main risk comes from the residues themselves rather than from the chemical alone. These findings are important for farmers because they provide practical advice on how much residue can be left in the soil and how long to wait before planting cotton. By managing residue levels and timing, farmers can enjoy the benefits of cover crops while avoiding risks to cotton production.