This leads to reduced oxygen levels and ultimately to reduced higher-order aquatic animal populations. Animal manures and bedding materials contain significant amounts of P in organic forms. After microbes convert P from the organic forms, the P is subject to the same fates as inorganic fertilizer P when applied to soils. You should base rates of land application of animal wastes such as poultry litter on soil tests, nutrient content of the material, and crop needs. Directions on getting nutrient analysis of manures are available at your Extension office.
Erosion is a major path of P movement in landscapes.
Because P is closely attached to solid soil materials, erosion control is very important in controlling P movement to surface soils. P needs of plants are most critical in the earliest growth stages. If the pH is between 6 and 7 and the soil has a low risk of erosion, P can be applied in the fall for cotton or grain production. Because P normally moves very slightly within the soil in the absence of erosion, corn and grain sorghum may benefit from P fertilization in a band near planted seed. Placement of fertilizer bands below and near the seed enhances the possibility of roots finding the fertilizer.