Rates and time of nitrogen application to maize in a soil with high rate of organic matter

Abstract

This experiment was carried out for the purpose of evaluating the effect of different rates of N and the influence of the splitting of side-dressing fertilization on agronomic traits of corn. A soil with high organic matter content (5,7%) located on the highlands of Santa Catarina state was used. Four rates (0, 50, 100 and 150 kg/ha) of N were tested. In the first application period, N was totally applied when the plants presented five expanded leaves; in the second, half of the dosage was applied when the corn presented five expanded leaves, and the other half, when de culture had nine expanded leaves. In 1990/91, there were long periods of water deficit; in 1991/92, the rainfall was normal. In 1990/91 the yield was low and the response to applied N was high in terms of increasing grain yield. On the other hand, when the water supply was normal, corn yield was high and the effect of N on grain yield was less pronounced than in 1991. There was no effect of the splitting of nitrogen side-dressing on grain yield and yield components.