Pesticides reduce crop losses due to insects, pathogens, weeds and other pests, but can contaminate ground water. Ground water refers to water in the saturated portion of the soil material. Water in an unsaturated region of the soil is termed soil moisture.
Peralta, Richard C.; Deer, Howard; Hill, Robert W.; and Allen, L. Neil, "Sprinkler Irrigation-Pesticide Best Management Systems" (1991). All Archived Publications. Paper 418.