Impact of above-ground dry matter residue from cover crops on fall-winter corn and spring- summer soybean yield under no-tillage system

Due to the high temperature and moisture in the region of Brazilian “Cerrado”, the greatest challenge in no-till system is the maintenance of above-ground dry matter. The aim of this research was to assess the above-ground dry matter production from cover crops and its effects on soybean and corn yield in Brazilian “Cerrado”. The experiment was carried out from 2012 to 2014 growing seasons. The experimental design was randomized blocks with four repetitions. The treatments (T) adopted were formed by different cover crops [fall-winter corn crop (T1); intercropping fall-winter corn with Brachiaria ruziziensis (T2); intercropping fall-winter corn with Brachiaria brizantha cv. Marandu (T3); intercropping fall-winter corn with Crotalaria spectabilis (T4); B. ruziziensis (T5); B. brizantha cv. Marandu (T6); Penisetum glaucum L. (T7) and reference area (T8)]. The above-ground dry matter productions were influenced by the treatments assessed through two growing seasons (2012/2013 and 2013/2014). There was interaction between the cover crops and growing seasons for above-ground dry matter of the cover crops. In relation to fall-winter corn yield, the cover crops and growing seasons showed significant effect on corn yield. The cover crops effect on soybean yield. The cultivation of intercropping fall-winter corn crop with B. brizantha cv. Marandu or this forage grass single showed higher production of aboveground dry matter, these values reached quantities over than 6 Mg ha -1 . The soybean crop yield decreased because of the aboveground dry matter production of the cover crop of B. brizantha cv. Marandu and the intercropping fall-winter corn with B. brizantha cv. Marandu.