Reference values for assessing the nutritional status of soybean crops in Mato Grosso

Resumo

Monitoring the nutritional status of the soybean crop, based on nutrient levels in the third trefoil with petiole, can help improve fertilization. The objective of this work was to determine the reference values ​​of macro and micronutrient contents, to evaluate the nutritional status of soybean crops, regarding the degree of balance and to obtain the potential response to fertilization for nutrients. The work was carried out based on a database of foliar nutrient contents and grain yield of soybean crops in Mato Grosso, Campo Novo dos Parecis region, covering different agricultural years, cultivars, soil textures and times of use of the area. with the soybean crop. They were obtained from useful reference values ​​for the evaluation of the nutritional status of soybean crops, regarding the degree of balance, plus limits of nutrient content in the normal range, according to the balance by the Kenworthy method. In low-yield soybean crops in the region studied, on average, for macronutrients, 69.7% of crops are in the normal class, while for micronutrients this percentage is lower, 60.9%. N is the nutrient most found in crops (83.2%), while Cu (49.8%) is the least found in the normal class. Of the low productivity soybean crops studied in this work, 78.3% have adequate nutritional balance. Mg, P and Ca and Cu, Mn and Zn are those for which there are greater expectations of crop productivity gains, in response to fertilization.