Nitrogen fertilization for maize in the state of Paraná. III. Influence of winter green manure on the responses to nitrogen fertilization

Abstract

The influence of winter green manure with lupine (Lupinus albus L.) on the response of four maize (Zea mays L.) cultivars planted at two plant populations to crescent levels of N was studied. The lupine was planted at the fall, by direct drilling over maize residues and was incorporated at flowering period. One month after, the area was disked and the maize sowed. Grain yields were related to others obtained in the same trial, at previous harvest, when the soil was degenerated by intensive use. The winter green manure was a good alternative for soil recuperation and contributed to reduce the nitrogen fertilizer needs. This alternative increased 26% of maize yields. The variety Cateto Prolífico showed a low efficiency of response to nitrogen fertilization, but gave a good response to the green manure practice. The cultivars AG-162, C-501 and Piranão showed high response to nitrogen fertilization, but the green manure practice was sufficient to supply his nitrogen needs.