COVER CROP SYSTEMS AND RESIDUE MANAGEMENT IN WEED CONTROL AND SOYBEAN YIELD

Abstract

Management systems, within the context of regenerative agriculture, have been identified as strategies to improve soil health and reduce the use of external inputs. These management systems that use conservationist practices seek to minimize yield losses due to climatic events such as droughts, but the effect of these practices on weed control is poorly documented. The main objective of the research was to evaluate the comparative effect between management systems with cover crops on weed density and soybean yield. This study was developed in the southern region of Brazil in a subtropical climate. The treatments in this study consisted of: conventional system using black oats as a cover crop, no-tillage system using black oats, and no-tillage system with a polyculture of cover crops. The results showed that no-tillage with the use of forage radish followed by a second sowing with several species of cover crops (polyculture) was efficient in minimizing the density and height of Conyza bonariensis and Solanum americanum. The suppression of these two weed species was associated with the greater production of dry matter from these cover crops and, consequently, resulted in a greater grain yield of soybeans grown in succession.