Residuals typically offer substantial benefit to the soils on which they are applied.
Processed sewage sludge, or biosolids, is a particularly valuable source of nutrients and soil-conditioning organic matter. The result is a decrease in the volume of reusable materials going to municipal landfills. Agronomic rates Application of excessive amounts of nutrients to the soil over time can result in an accumulation of those nutrients below the root zone. These accumulated nutrients could eventually contaminate groundwater. To prevent this potential contamination, residuals must be applied to the land at agronomic rates, i.e., rates at which all the added nutrients will be utilized by the crop.