USO DE BIOESTIMULANTE À BASE DE SUBSTÂNCIAS HÚMICAS NO CULTIVO DE SOJA IRRIGADA E NÃO IRRIGADA

Abstract

Soybean is the most important and most cultivated oilseed in Brazil and worldwide, being of great importance in animal and human nutrition. New technologies have been used to increase its production, including the increasing use of natural and economical sources such as biostimulants. Humic substances composed mainly of humic and fulvic acids are among the main biostimulant compounds currently used. This study aimed to evaluate the biostimulant effect on the soybean development and yield in irrigated and non irrigated management systems. The experiment was carried out in a randomized block design of split plots with five replicates in a 2x2 factorial scheme consisting of irrigation management (irrigated and non-irrigated) and the subplots by the management using or not using biostimulant. Soybean seeds of the HO Juruena Ipro cultivar were sown and the biostimulant (16.7% humic acids, 1.3% fulvic acids, 0.5% nitrogen, and 14% total organic carbon) at a dose of 1.5 L ha-1 was applied via planting furrow at the sowing time. Plant height, dry mass of the aerial part, stem diameter, number of internodes, seed vigor and viability, number of pods per plant, thousand-grain weight and grain yield were evaluated on the 125th day after sowing and at the end of the reproductive stage (R8). In the irrigated cultivation system, the biostimulant Black Gold ® provided an increase in plant height (92.42 cm), dry mass of the aerial part (43.26 g), number of internodes (14), and seed vigor and viability (83.16% and 84.36%, respectively). In the non-irrigated crop system, the biostimulant provided an increase in plant height (67.96 cm), dry mass of the aerial part (44.63 g), stem diameter (8.88 cm), number of internodes (13.32), number of pods (127.04), mass of a thousand grains (153.60 g), and grain yield (35.54 g/plant). The biostimulant positively influenced the soybean development and yield, being promising for use in the crop. ix Keywords: Glycine max. Humic acid. Leonardite. Mineral fertilization