Biosolids are the solid or semisolid, largely organic, nutrient-rich residuals of wastewater (sewage) treatment, i.e., sludge treated to meet EPA (and sometimes state) land application standards so that they can be used beneficially and safely as a fertilizer or soil amendment. Similar to livestock organics, the nutrient content of biosolids may vary considerably, depending on the influent waste properties and treatment process. This research aims to determine nitrogen (N) and phosphorus (P) availability coefficients of different types of biosolids applied to North Carolina’s diverse soils to determine application rates appropriate for crop needs and water quality protection.