MANEJO NUTRICIONAL E FISIOLÓGICO PARA ALTAS PRODUTIVIDADES DE SOJA

Abstract

Soybean is the most widely produced grain crop in Brazil, with different industrial applications and great importance in human and animal food. During its growth and development, the crop needs an adequate supply of water, light and various nutrients, which play important roles in plant metabolism. Foliar nutrition is an important tool as a management strategy aimed at supplementation with lower doses than those used in soil fertilization. The aim of this work is to determine whether the increase in terms of foliar nutritional management would also result in an increase in souybean yield. The experiment was set up and conducted in the field for two harvests in the municipality of Rio Verde - GO. Five treatments were carried out in a randomized block design and with five replications. The treatments were represented by incremental management, as described below: T1: Control (without any management); T2: T1 + (Mn chelated with EDTA); T3: T1 + T2 + (N, P, Mg, S and B) + (Ni, Co, Mo, Zn, Mg, S, P and K) + (Aminoacids) + (Cu chelated in EDTA) T4: T1 + T2 + T3 + (K, Mg, S, Mn, Zn, B and Cu); T5: T1 + T2 + T3 + T4 + (Mg, Zn and Se). For each treatment, the applications were made at the following times: T1 control, T2 (V2 - V5) associated with the application of glyphosate and post-emergent, T3 end of the vegetative phase (V8 - R1), T4 flowering (R2 - R3), T5 grain filling (R5.1). The applications were made using equipment pressurized by a compressed CO2 cylinder. The following assessments were carried out: biometry (plant height and stem diameter), estimation of chlorophyll a and b content with a portable chlorophyll meter, analysis of plant photosynthetic parameters with IRGA, analysis of foliar nutritional diagnosis, export of nutrients by the grains and productivity. Harvesting and threshing were carried out manually, observing the useful area of the plots. The data was subjected to analysis of variance and the means were compared using the SNK test at 0.05% probability. It was possible to observe that by using foliar fertilization as a complementary strategy in agronomic management, carried out according to the crop's demand, at different stages of development, the nutrients supplied perform important functions in the plants, acting on their metabolism, promoting increases in plant structure, chlorophyll levels and photosynthetic rate, resulting in greater productivity, with this best response expressed by treatment 5