Improvement of soil fertility as affected by the addition of enzyme industry wastewaterA field experiment was carried out in an Ultisol, in which maize (Zea mays, var. AG303) was cultivated, in Araucária (Paraná state, Brazil). Mineral fertilization was compared with four doses of wastewater of enzyme industry (0, 80, 160 and 320 t ha-1) with five replication. Chemical and physical characteristics of enzyme industry wastewater were determined. Determinations of K, P, organic carbon, soil pH (CaCl2), Ca+2, Mg+2, (Al+3 + H+) and base saturation were made. Increase in grain maize yield was obtained with the wastewater application for all treatments due to the nutrient content. Soil pH increased and Al+3 contents decreased with the application of treatments due to neutralization properties of enzyme industry wastewater. For the maize crop, the industrial wastewater tested may replace soil mineral fertilization and lime when applied at rates of 160 and 320 t ha-1.
nitrogen; corn; acidity; land farming; industrial residue
