Desempenho fisiológico da cultura de soja sob diferentes tratamentos com plantas de cobertura cultivadas em segunda safra

Abstract

The significant expansion of agricultural frontiers in Mato Grosso in recent years, driven by global demand for agricultural commodities, including soybeans, has led to a trend of expanding cultivation areas for this crop into transition regions between the Cerrado and the Amazon. In this context, the introduction of cover crops in the second crop, after soybean harvesting, has been adopted as a management strategy. This practice aims to improve soil quality, reduce erosion, accelerate the recovery process, and promote nutrient cycling, resulting in increased soybean crop productivity in succession. Thus, this study aimed to evaluate the physiological performance of soybean crops under different treatments with cover crops grown in the second crop. For this purpose, the experiment was conducted in the municipality of Sinop-MT, evaluating various physiological and production factors related to the crop subjected to different second crop consortia during the 2018/2019 season. Five of these treatments involved production with cover crops (cowpea, buckwheat, forage turnip, gandhu bean, and sextuple), while another treatment involved the succession of cotton and maize. The following properties were evaluated: stomatal conductance, transpiration, leaf temperature, net photosynthetic rate, intercellular carbon concentration, water use efficiency, plants per meter, plant height, grain mass, and productivity. Based on the observed results, it can be concluded that the sextuple treatment stood out as the most effective, showing significantly positive differences compared to the other treatments, both in eco-physiological terms and in productivity. On the other hand, the cotton treatment recorded the worst performances. It is important to note that the treatments with direct planting systems (cowpea, buckwheat, forage turnip, gandhu bean, and sextuple), although not showing significant differences, indicated a trend towards superior results. These treatments provided more suitable water conditions for soybean cultivation, favoring the opening of stomata, which is crucial for increasing photosynthesis and carbon dioxide absorption by plants, resulting in a significant improvement in soybean productivity.