The effect of different cover crops on maize yield was investigated in the second no-till year, in Passos, Minas Gerais, Brazil. White oats ( Avena sativa), black oats [ Avena nuda], Brachiaria decumbens [ Urochloa decumbens] and forage turnips were cultivated in the same plots as in the previous winter, and were subsequently sown with maize. The forage crops were sown in lines in May 2004 and desiccated in October 2004, after the determination of dry matter yield. Maize was sown in each plot and the soil organic matter and grain yield were determined at the end of the cropping season. The black oats yielded the greatest amount of mulch; however, this increase did not affect the soil organic matter, in relation to all other treatments, and maize yield in the no-till system.
