Nutrição, trocas gasosas e metabolismo do nitrogênio de plantas de milho sob aplicação de uréia estabilizada (NBPT) em texturas de solo.

Abstract

Urea is the most widely used source in the world; however, in agricultural systems it estimates a loss of 5 to 30% of N to minimize NH 3 loss, some technologies have been developed, such as N- (n-butyl ) thiophosphoric triamide) (NBPT). The objective of the study was to evaluate the effect of nitrogen fertilizer treatment with urea inhibitor (NBPT) on two different textured soils in the vegetative, physiological and biochemical development of maize. The experiment was carried out in a greenhouse at the Federal Rural University of Amazonia / Belém-PA, where the experimental design was a completely randomized, 5 x 2 factorial scheme consisting of 5 doses of N (NBPT) (0,50,100, 150 and 200 kg ha-1 of N) in Yellow Latosol of distinct textures (clayey and sandy loam) with 5 replicates. Were evaluated the height, diameter, specific leaf area and dry mass of the aerial part (phytotechnical variables),photosynthesis, conductance, transpiration, internal concentration of CO2 (physiological variables) , proteins, amino acids, ammonium, nitrate (biochemical variables) and macronutrient contents (N,P,K,Ca,Mg). The N doses (NBPT) significantly influenced the studied variables (phytometric, gas exchange, biochemical and nutritional), with the exception of the internal CO2 concentration. The maximum efficiency dose was obtained between 100 a 150 kg ha-1 de N, where the best results were provided in the soil of sandy loam texture. The urea treated with urea inhibitor (NBPT) promoted better N utilization by maize culture, regardless of soil texture.