Biosolids are used to fertilize fields for raising crops. Agricultural uses of biosolids, that meet strict quality criteria and application rates, have been shown to produce significant improvements in crop growth and yield. Nutrients found in biosolids, such as nitrogen, phosphorus, and potassium, and trace elements such as calcium, copper, iron, magnesium, manganese, sulfur, and zinc, are necessary for crop production and growth. The use of biosolids reduces the farmer’s production costs and replenishes the organic matter that has been depleted over time. Organic matter improves soil structure by increasing the soil’s ability to absorb and store moisture. The organic nitrogen and phosphorous found in biosolids are used very efficiently by crops because these plant nutrients are released slowly throughout the growing season. This enables the crop to absorb these nutrients as the crop grows. This efficiency lessens the likelihood of groundwater pollution of nitrogen and phosphorous.