Adubação potássica de cobertura na soja em solos com fertilidade construída

Abstract

With the diversity of soils, crops and fertilization habits, it is essential to diagnose the potassium already existing in the soil, as one of the prerequisites for the prescription of fertilization. When present in insufficient contents, potassium deficiency will have a direct impact on the development and subsequent productivity of soybean. With the constant increase in the demand for exporting this grain, it is of paramount importance to carry out the best possible management in order to increase productivity without increasing the planted area. On the other hand, potash is one of the fertilizers that is more subject to market price variations due to its high degree of importation, which forces us to always look for alternatives for the producer to circumvent this volatilization of the foreign market. The objective of this study was to evaluate whether topdressing potassium fertilization would have a great impact on production, since the levels present in the soil were already considered adequate. 3 sites were separated, where each site had two treatments, with and without potassium application, and each treatment had 4 replications, where the fertilized plots received 139 kg. ha−1 of K2O. The potassium source used was KCl, which is one of the most used sources in agriculture. The application was carried out at the phenological stage of R1. The application of 139 kg of K2O per hectare did not show significant results in soybean yield, since the potassium contents present in the soil were sufficient to achieve high yields.