Nitrogênio no feijoeiro em sistema de plantio direto sobre no feijoeiro em sistema de plantio direto sobre no feijoeiro em sistema de plantio direto sobre no feijoeiro em sistema de plantio direto sobre gramíneas

sementes. ABSTRACT. Nitrogen in common bean in no-tillage system over gramineae. An adequate supply of nitrogen is essential for high yield of common bean seeds; however, the responses to this nutrient in no-tillage systems can vary in function of the species and the amount of straw present. The aim of this research was to evaluate response of the common bean to N in no-tillage systems over maize, millet and Brachiaria brizantha crop residues. Three experiments were conducted, one for each gramineous species. The experimental design was a randomized block in a 5x2x2 factorial scheme, with five N doses (0, 30, 60, 90, 120 kg ha -1 ), in two distinct stadia during the vegetative development (3 rd and 6 th trifoliate leaf) and two common bean cultivars ( IPR Juriti and Perola ), with four replications. The IPR Juriti produced a greater number of pods per plant and showed lower mass per 100 seeds than Perola . It did not show variation in bean yield when the sidedressing N application was carried out in the 3 rd or 6 th trifoliate leaf stadia. Based on the obtained results, one concludes that the seed productivity of common beans increases linearly with N doses in a no-tillage system over maize residues.