Assessing Vegetable Growth and Yield Response to Graywater Irrigation

The impacts of graywater irrigation on soil properties and vegetable yields were assessed through a three-year field experiment for Bell Pepper, Chile, and Tomato in El Paso, Texas in the United States. Two irrigation treatments including freshwater (well water and sand filter effluent) and graywater (laundry water) with three replications were utilized in the study. Duncan’s multiple range test at the significance level of 0.05 was used to test changes in soil properties including soil pH, salinity, and sodicity, and mean differences in vegetable growth and yields in terms of fruit height, fruit count, weight, and fruit sizes under freshwater and graywater irrigation treatments. The statistical analysis suggests that no evident salt accumulations or changes in salinity and sodicity were observed at the soil surface in the depth of 0-15cm, while soil pH is increased significantly with graywater irrigation. The growth and yield of Bell pepper and Chile under graywater irrigation tend to increase as compared to freshwater irrigation although the results for the third year were not significant. No yield decreases regarding fruit weight, fruit counts and fruit sizes were observed for all vegetables. It can be concluded from the experimental research that the graywater has shown promising potential as an alternative water supply for vegetable production in the El Paso region, Texas.