WHEAT NITROGEN FERTILIZATION UNDER NO TILL ON THE LOW ALTITUDE BRAZILIAN CERRADO

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Processo FAPESP: 06/04277-3

This study evaluates the effects of different nitrogen (N) rates (0, 50, 100, 150, and 200 kg ha(-1)) and sources (ammonium sulfate, urea, and ammonium sulfonitrate with a nitrification inhibitor, Entec (R)) applied either as a single application during sowing (next to the planting rows) or as side dressing (stage 3.2 on Zadok scale), on production components and grain yield of irrigated wheat grown under no-till in a low-elevation Brazilian cerrado and Dark Red Dystrophic Latosol with clayey-texture. It was adopted a randomized block design (5 x 3 x 2) in factorial scheme with four replications. The N sources provided similar grain yields and chlorophyll contents. Increased nitrogen rates increased grain yield up to the 120 kg N ha(-1), regardless of application time and N source. Nitrogen fertilization as side dressing can be recommended based on leaf chlorophyll readings. Early application of all nitrogen fertilizers at sowing time was viable.