Nutritional Evaluation by the DRIS Method of Corn Plants Fertilized with Sewage Sludge Biochar

Abstract

ABSTRACT Through pyrolysis it is possible to transform sewage sludge (SS) into a product called biochar, which can be used safely in agriculture as a soil amendment. Among the advantages of using SS biochar (SSB) are the supply of nutrients and carbon sequestration in the soil. However, there is still a lack of information on the supply of nutrients and the nutritional balance provided by SSB application. The objective of this study was to evaluate the nutritional status of corn plants fertilized with SS biochar by the DRIS method. Soil and plant data from a three-year field experiment were assessed. The field experiment, with four replications, consisted of the following treatments: 1) control, no biochar and no mineral fertilization; 2) mineral fertilization; 3) biochar produced at 300°C; 4) BC300 associated with mineral fertilization; 5) biochar produced at 500°C; 6) BC500 associated with mineral fertilization. In the present study, leaf samples of corn cultivated for three consecutive harvests were used. From the DRIS indexes, it was concluded that potassium is the most limiting nutrient for SSB. Despite that, according to outputs from DRIS, SSB has a good potential as a fertilizer, especially if supplemented with K.