Representative samples of the material to be land applied should be analyzed twice annually for nutrient and mineral content. The N.C. Department of Agriculture provides this service with interpretations of results for a nominal fee. Soil infiltration rates will often determine maximum irrigation rates or how much lagoon liquid can be applied before runoff occurs. Soil types also determine the fate of unused nutrients. Well- drained sandy soils provide more potential for unused nitrogen to convert to nitrates and leach downward.
Clay soils have more capacity to tie-up and hold phosphorus in place than do coarse soils.
Soil types also influence the yield potential of selected crops. Crop types should be selected for their nutrient requirements. A range of fertilization rates from 50 lbs of available nitrogen per acre on stands of pine trees to 400 lbs of available N on bermudagrass hayland allow flexibility depending on land availability and farm objectives. Application Rates Application rates of manure, litter or wastewater should only supply the fertilizer needs of the crops. Some overapplication of phosphorus and potassium may be tolerated, however significant and prolonged overapplication of P and K should be avoided.