Diagnose da composição nutricional para a cultura da soja na região centro Sul do Mato Grosso do Sul

Abstract

The present study aimed to develop Compositional Nutrient Diagnosis (CND) standards for soybean crops from Mato Grosso do Sul, developing preliminary reference standards for the diagnosis of the nutritional composition of leaf tissue of the soybean plant, through the use of nutrient concentration s processing by the logarithmic relationship centered on [centered log-ratio (CLR)], checking for efficiency in the use of Mahalanobis and Cate Nelson distance in reference population selection, and subsequently validating these standards by diagnosing the potential to respond to fertilization of the plots analyzed within the reference population. The work was carried out in the south-central of Mato Grosso do Sul, in commercial areas that use the succession of the soybean-corn crop, and have had lime applications in the last two years. Being carried out in 32 farms, located in the municipalities of Aral Moreira (8 farms), Dourados (8 farms), Laguna Caarapã (8 farms), and Ponta Porã (8 farms), during the 2017/18 and 2018/19 harvest. Leaf collection was performed when the plants reached the phenological stage R2, and productivity was determined by harvesting all plots when the plants reached the R8 stage. The use of Mahalanobis and Cate-Nelson distance makes the selection process of the reference population more rigorous with the exclusion of outliers making the database more effective for the development of CND-clr standards. Through the analysis of the potential response to fertilization, it was diagnosed that the elements that have the greatest deficiency and thus would respond to fertilization returning in greater productivity in the analyzed samples are respectively: N, K, S, Mg, Zn, B, P, Ca and Fe. Nitrogen is the nutrient that showed the highest frequency as deficient in the analyzed plots, based on the history of the area, it is concluded that this deficiency is not due to the lack of this nutrient in a mineral form, but rather to improve the management of crops used a in order to improve the availability of this nutrient organically.