Response of irrigated rice to green manure and chemical fertilization in the State of Tocantins

摘要

Lowland rice is an important crop in Brazil due to its socio-economic value. Often due to inadequate fertilization, production is limited. Two field experiments were conducted at Xavante Farm, Municipality of Dueré, State of Tocantins, Brazil, during two consecutive years to determine the response of irrigated rice to green manure and to chemical fertilization grown in an Inceptisol. The treatments consisted of green manure + N0P0K0; green manure + N100P120K100; green manure + N50P60K50; green manure + N75P90K75; green manure + N45P120K100 (application of N, P, and K at sowing); green manure + N45P120K100 (application of P and K at sowing and N topdressing); green manure + N100P120K100 + 4 Mg lime ha-1; and without green manure + N100P120K100. Maximum grain yield was obtained with the application of green manure + N45P120K100 (application of P and K at sowing and N topdressing). Among yield components, panicle length was significantly and positively influenced by fertilization. These results show that green manure can reduce chemical fertilization, and hence cost of production.