Efeito da reaplicação de gesso no desenvolvimento da cultura da soja

Abstract

Agricultural gypsum is capable of reducing the activity of toxic aluminum and favoring the mobility of cations such as calcium, magnesium and potassium, taking these nutrients to the subsoil, for which reason its use has been increasing with the aim of correcting the soil profile. , in order to further deepen the roots in the search for water and nutrients, factors that contribute to greater productivity and greater crop safety in summer periods. However, when high rates of this product are used, leaching of magnesium, and in some cases also potassium, beyond the root uptake zone is commonly observed, which can reduce crop productivity. The objective of this work is to evaluate the effects of the reapplication of increasing doses of gypsum, two and a half years after the initial application, on the behavior of the soybean crop, in an Oxisol with a very clayey texture. The experimental design was randomized blocks with a total of five treatments, with doses of 0, 2, 4, 6 and 8 t ha-1, reapplied on the surface and with four repetitions. The gypsum doses were reapplied in June 2021, preceding the wheat harvest. The soybean cultivar used was BMX ZEUS IPRO, planted in a zero tillage system on wheat straw. Yield components (number of pods per plant (NVP), number of grains per pod (NGV) and thousand grain mass (MMG)), morphological characters (plant height (AP) and first pod insertion height ( AIPV)) and grain yield (GR). The reapplication of the plaster two and a half years after the initial application did not affect any of the variables analyzed, even with a period of water deficit during the vegetative phase of the crop.