Economic analyses on water depth and nitrogen doses in maize, <em>Zea mays</em> L., by CERES-Maize Model

Abstract

CERES-Maize model from DSSAT 3.0 package was used to simulate the necessary data for current research with BR-201 maize cultivar, undertaken in the Janaúba district, Minas Gerais, Brazil. Maize yields for three sowing dates, or rather, 15^th May, 15^th October and 15^th November, were simulated in non-irrigation and irrigation conditions. In the latter water depth was kept at 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44 and 48 mm at seven-day intervals. Water depth coincided with nitrogen doses of 0, 30, 60, 90, 120, 150, 180 and 210 kg ha^-1. Climatic data of the 1977-1995 period were used in simulations. Analyses showed that economical gain for the 15^th May sowing was higher than that on other dates, even though water depth had to be greater. This was due to the fact that average rainfall during the culture cycle in the 1977-1995 period was just 12mm