Influência de fontes e modos de aplicação de nitrogênio nos componentes da produção e produtividade do milho irrigado no cerrado

Abstract

The objective of this experiment was to compare the effect of nitrogen sources: ammonium sulfonitrate with nitrification inhibitor, ammonium sulfate and urea, applied at sowing and/or as side dressing) on the leaf content of N and chlorophyll content, yield and production components of corn grown in savannah soil, under sprinkler irrigation. The research was carried out on Oxisol, during crop years of 2006/2007 and 2007/2008. The experimental design was the randomized blocks with four replications, in a 3x5 factorial outline consisting of: three nitrogen sources applied at sowing and/or side dressing at the 8 unfolded-leaf stage, in five different application ways (0 +120; 30 + 90; 60 + 60; 90 + 30 and 120 + 0 kg ha -1 of N). The application of sulphonitrate ammonium + inhibitor was similar to ammonium sulfate on the corn yield components, regardless of time of application. The application of 120 kg ha -1 of N as urea in a single application at the stage of eight leaves in corn and in periods with high precipitation affects negatively the foliar N content and results in less grain yield in relation to the application of the same dose at sowing.