Cultura do milho: fixadores biológicos de nitrogênio e adubação em cobertura

Abstract

Corn (Zea mays) is one of the world's most widely grown cereals. To ensure high productivity, corn requires a large amount of fertilization, mainly nitrogen. The use of nitrogen in large quantities increases the cost of production, in addition to polluting lakes, rivers and groundwater due to leaching. To reduce its use and optimize production some studies point to the maximization of the FBN process. Among the nitrogen-fixing bacteria, the genus Azospirillum brasiliense stands out, which is able to fix the atmospheric nitrogen in the form of N2 unavailable to the plants and transform it into NH3 in which it is assimilable by the plants. The objective of this work was to evaluate the effect of increasing doses of nitrogen fertilization on the components of yield, grain yield and spike insertion height in corn crop with presence and absence of inoculation of Azospirillum brasiliense. The experiment was conducted in the municipality of Barra-Funda with a randomized block design with 3 replicates, totaling 30 experimental plots. The factorial scheme was characterized by nitrogen doses x inoculant application. The doses used were 0, 50, 100, 150 and 200 kg ha -1 in the presence or absence of inoculation with Azospirillum brasilense. Statistical software SASM-Agri and SigmaPlot were used. Nitrogen Dose x Inoculant Application was observed for none of the analyzed variables. A positive linear effect of increasing doses of nitrogen fertilization was observed for NGE, MGE, PGP, PMW and AIE for maize in both situations, whether inoculated or not. The inoculation of Azospirillum brasilense in maize showed a beneficial effect on the NGE and MGE variables only, whereas for PP, PMS and AIE, no significant effect of this inoculation was observed in any of the nitrogen fertilization doses.