Greywater irrigation of pepper plants: Possible application and its impact on soil and plant growth

Greywater reuse may be considered a water source that can compensate for water scarcity. Reusing treated greywater on fields instead of disposing of it would be more environmentally friendly. The objective of this study was to investigate the physiological response of pepper plants to the application of both untreated and treated greywater. The greywater obtained from Al-Huson University College was treated with zeolite filters before being used for plant irrigation in the experiments. The electrical conductivity (EC), total dissolved solids (TDSs) and chemical oxygen demand (COD) of greywater were all higher than those of tap water by 44%, 68% and 509%, respectively. The results demonstrated that plants irrigated with tap water and treated with greywater presented greater fruit and biological productivity than did those irrigated with untreated greywater. The use of treated greywater led to a notable 8.3% increase in overall chlorophyll levels. Irrigation of pepper plants with untreated greywater led to a 33% increase in electrolyte leakage. The plants irrigated with greywater presented the highest levels of proline and total soluble sugars. Compared with those in all the other water treatments, the plants irrigated with greywater presented significantly greater magnesium and salt concentrations. Typically, treated greywater has the most significant impact on agricultural productivity.