Efeito da aplicação de água residuária de café sobre as propriedades químicas do solo e do efluente

Abstract

The competitiveness and the requirement of the international market, for products have motivated the Brazilian producers the search of alternatives for better quality attainment of better quality coffee. However, the selected alternative generates wish volumes of waste water with high pollutant potential due to organic load and the nutrient concentrations. The high nutrient concentrations, mainly potassium, in the wastewater from coffee processing become an alternative for exploration in agriculture. However, little is known about the alterations that can happen in atmosphere with the use of sich wastwaer. Hence it has been aimed to evaluate the chemical characteristics of soils treated with wastewater of washing and husking of the coffee cherries (WCC) and the effluent quality. The experiment was constituted of four doses of ARC, two samples of soil and two incubation periods, arrangement in factorial design, with three repetitions, comprising 48 PVC columns with 20 cm of diameter and 1 m of height. The applied WCC were doses of ARC had been: Dose 1 = control (2.70 water L), Dose 2 = 0.54 L, Dose 3 = 1.62 L and 2.70 Dose 4 = L of ARC for column based on the recommendation of soil potassium for the coffee plant (80 g K2O for plant) and on the concentration of K in the WCC. After theWCC application and elapsed the incubation periods, an irrigation of 120 mm WAS applied, and it WAS collected. The leached was analysed pH, Ca, Mg, K, Na, electrical conductivity (EC), dissolved solids total (TDS), chemical demand of oxygen (COD). In order to evaluate the chemical alterations after wastewater application , coffee samples have been collected in each column for analysing calcium (Ca), magnesium (Mg), potassium (K) and sodium (Na) exchangeable, pH, electrical conductivity. In general, In general, it has been verified that the doses of WCC increased the concentrations of Ca and K in the two time treatment, for the two soils, concentrating more K in the deh from 0 to20 cm. In the leached, the growing doses of WCC promoted increases of concentration of Ca Mg , Na and K, but with values sower than the applied WCC.