Coberturas vegetais, doses de nitrogênio e inoculação com Azospirillum brasilense em milho no Cerrado

Abstract

With the aim of increasing productivity, and minimising costs and environmental impact, sustainable management techniques are necessary when growing maize. The aim of this study was to evaluate different cover crops (millet, crotalaria, pigeon pea, millet + crotalaria, millet + pigeon pea and fallow) and doses of N (0, 40, 80 and 120 kg ha-1), both with and without seed inoculation with Azospirillum brasilense of the maize crop, in the Cerrado region of Brazil. The experimental design was of randomised blocks, in a 6 x 4 x 2 factorial scheme, comprising 48 treatments with 4 replications. The study was carried out in the town of Selvíria, in the State of Mato Grosso do Sul. Plant cover, except for the pigeon pea in the first year and the fallow in the second year, produced enough residue (6 t ha-1) to maintain the no-tillage system in the Cerrado region, especially the treatment with millet + crotalaria. Maize production in succession to the pigeon pea and the millet + crotalaria was higher. In an area with a stabilised no-tillage system, the supply of nitrogen using fertiliser, gives an increase in productivity up to a dose of 114 kg N ha-1. Inoculating the seeds with Azospirillum brasilense gave a smaller final plant population, less plant height and lower 100-grain weight.