Interaction of chemical attributes of a Regossol cultivated with beans and fertilized with biochar

Abstract

The world's population is predicted to reach 10 billion people by 2050, increasing the need for food and encouraging farmers to work on applying technologies to increase crop productivity. Furthermore, the increase in the cost of synthetic fertilizers makes the use of organic matter in soils viable. Therefore, the objective of this study was to evaluate the use of multivariate statistics through the analysis of the main components in the contents of chemical elements in two layers of soil in a bean cultivation cycle and to determine the possible correlations of the variables with the respective treatments. Biochar was made from sewage sludge. Cultivation was carried out under rainfed conditions. The treatments used were NPK = synthetic fertilizer; B5 = Biochar 5 t ha^-1; B10 = Biochar 10 t ha^-1; B20 = Biochar 20 t ha^-1; B40 = Biochar 40 t ha^-1; CM = chicken manure 5 t ha^-1; and SS = Sewage sludge 5 t ha^-1. In the 0-0.1 m layer, PC1 explained 71.82% of the data variability, influenced by K, P, Mg, SO42-, TOC and N, while PC2 influenced salinity and acidity. Biochar, at doses of 20 and 40 t ha^-1, improved nutrient availability. In the 0.1-0.2 m layer, PC1 explained 84.39% of the variability, with contributions from all variables, while PC2 influenced the Mg concentration. Therefore, the application of biochar is a sustainable and promising practice to increase productivity in the Agreste of Pernambuco.