ABSTRACT

There is a worldwide concern regarding the management of agroindustrial residues, involving sustainable practices that contribute to taking advantage of the residues as inputs in productive processes, allowing greater efficiency in the integration of agricultural activities and mitigating their adverse effects on the soil. Therefore, the objective of this study was to assess the effects of application of cassava wastewater on the chemical attributes of the soil cultivated with Brachiaria brizantha cv. Marandu. The experimental design was in randomized blocks with five treatments (0, 15, 30, 60 and 120 m³ ha^-1 of cassava wastewater) and four repetitions. To characterize soil chemical attributes soil samples were collected at depths 0 to 10 and 10 to 20 cm, for determination of the concentrations of soil organic matter, available phosphorus, exchangeable potassium, sodium, calcium and magnesium before and after cassava wastewater application were determined. The application of cassava wastewater increases available phosphorus and exchangeable potassium concentrations, decreases exchangeable calcium, magnesium and organic matter contents of the soil cultivated with Marandu grass. Cassava wastewater can be used as organic fertilizer for pastures of Marandu grass with doses of up to 120 m³ ha^-1.

Key words:
biofertilizer; macronutrients; ‘manipueira’; soil fertility