ABSTRACT
Large amounts of waste are produced daily by several industrial branches in Brazil, many of which can be used in agriculture. Applying nutrient-containing waste onto soil might minimize dependence on chemical mineral fertilizers, contributing to sustainable agriculture. Some of this waste increases soil pH, similar or even superior to that of limestone, providing opportunities for use in acidic soils. Different industrial waste may have elements that alter the electric charge of clay surfaces, which may alter soil physical characteristics related to dispersion and flocculation and consequently soil aggregation. Therefore, the presence of sodium may cause the dispersion of clays and calcium-containing waste, as its components may improve aggregation. The application of industrial waste can add heavy metals to the soil and, consequently, environmental problems if performed without strict regulations. Brazil has large industrial and agricultural areas, to which waste can be applied to supply part or all of the nutritional plant demand. To be recommended as economically effective and environmentally safe, a thorough waste analysis, chemical characterization of the soil, and knowledge of the nutritional requirements of the crop to be grown are required.
Acknowledgments
The authors thank Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Grupo de Estudos em Solos da Universidade Estadual de Maringá (GESSO) (In Portuguese).
Conflicts of Interest
The authors declare no conflict of interest.