Industrial effluents: Impact on agricultural soils and microbial diversity

Abstract

One of the most important alternative water resources in regions where scarcity of freshwater is common is the application of industrial effluents. The application of different, treated industrial wastewaters/effluents and sludge on agricultural fields offers an alternative to disposal by utilizing it in the production of crops. Industrial effluents could provide sufficient water and essential nutrients required for plants since they are very rich in organic matter, minerals, metals, etc. These effluents added to the soil in sufficient quantities would improve the soil’s physical condition and render it a more favorable environment to manage water and its nutrient content. Irrigation with such a kind of water might affect the diversity and function of the soil microbial community and alter the structure of soil. However, unlike manufactured fertilizers in which nutrient properties are managed to suit the crop requirements, the nutrients in the effluents are totally uncontrolled. Thus, before application to agricultural lands, the effluents should be treated at agronomic rates for satisfying the requirements of nutrients to be in excessive or in deficient amounts. The fate and transport of potentially harmful constituents in the environment are also of great concern. If the constituents from effluents are not immobilized in the soil surface, they might escape the root zone and leach groundwater. Thus, this chapter reviews the possible physical and chemical changes on agricultural soil as well as on crops as a result of wastewater application for irrigation. This chapter also improves our understanding on how irrigation with wastewater changes the activity of soil’s microbial process.