Desempenho agronômico de diferentes cultivares de soja com a utilização da irrigação suplementar na safra 2022-23

Abstract

Soybean is the main spring-summer crop in the state of RS and studies that contribute to the increase of its productivity per area are important for the sustainability of the crop. Thus, the objective of this study is to evaluate and compare the yield components and productivity of twenty-two soybean cultivars in one year of Lã Niña (2022-23) in the central region of the state of Rio Grande do Sul, with and without supplementary irrigation. The experiment was carried out in the field in the experimental area of UERGS – Cachoeira do Sul, with sowing on 11/26/2022. The experiment was conducted in a randomized block design in a factorial scheme (2 x22), with factor "A" being two water regimes (irrigated and rainfed) and factor "B" 22 soybean cultivars and three replications, totaling 132 experimental plots. The 22 soybean cultivars were chosen according to availability (seed donation). Irrigation was performed by a conventional sprinkler system based on information from the water balance of the crop. It was observed for the agricultural year 2022/23 in Cachoeira do Sul, that the rains were in low quantities and poorly distributed during the soybean cycle, totaling only 152 mm of rain, insufficient to meet the need for the crop. The supplementary irrigation of 244 mm added significant values to the agronomic performance of soybeans, increased by approximately 86% the HAI of the plants, by 114% the pods per plant, by 26% the PMG and, on average, 111% more productivity. The cultivars BXM CROMO, BXM COMPACTA, BXM TORQUE, BXM LOTUS and NEO 580 obtained the best results in the irrigated water regime, with productivity from 4948.9 kg ha-1 to 5195.4 kg ha-1 . While, in the dry water regime, the cultivars BMX GARRA, BMX RAIO, BMX LOTUS, BMX CROMO and NEO 590 I2X, had the best yield values, ranging from 2617.9 kg ha-1 to 2319.6 kg ha-1 . Thus, the results of this study contribute to the definition of management practices that increase soybean productivity in the study region.