Application of Wastewater in Irrigation and Its Regulation with Special Reference to Agriculture Residues

Growing urban agglomeration across the world has promoted unscientific disposal of wastewater. In this view, wastewater exploitation in agriculture is a sustainable way of its utilization. Application of wastewater as irrigation water serves several goals such as promoting sustainable agriculture in an arid and semiarid region, preserving scarce water resources, and maintaining growth of plants. However, inadequate practices of wastewater application in present decades have resulted severe environmental issues like degrading river quality, groundwater pollution, heavy metal contamination, deterioration in soil health and nearby water reservoir quality, etc. With the treatment, the wastewater can be purified up to a certain level, but they cannot remove some constituents like heavy metals, pesticides, and other organic and inorganic compounds. Due to the unpredictable and unstable nature of wastewater, this becomes costly to treat either physically, chemically, or biologically. In this context, with the application of some sustainable strategies, the contamination can be reduced up to a certain extent particularly for heavy metals. Among all strategies, the applications of agricultural residues such as rice husk, sawdust, and other amendments are found to be the most suitable and lucrative way of reducing metal availability. Therefore, adjusted and scientific use of wastewater with certain treatment can be an economic and environmentally sustainable alternative to chemical fertilizers for enhancing crop productivity and crop yield and, at the same time, help in handling wastewater as a valuable resource.