While most soils have a tremendous capacity to absorb phosphorus, very high soil phosphorus levels can interfere with plant nutrition by inhibiting uptake of metallic trace elements such as iron, zinc, and copper. When plant residue or manure is added to soil, there is an immediate and marked drop in O 2 and an increase in CO 2 in the soil air, which can inhibit plant growth. All the immediately available nitrogen is bound by the microorganisms. In the short run, nitrogen is unavailable for plant use and more chemical fertilizer may have to be added than before the waste application. Heavy manure applications can increase soil salinity, especially in arid regions where little or no leaching occurs.
Salts can inhibit plant growth and depress yields.
If salinity becomes a problem, consult a soil specialist. Sodium and potassium can alter soil structure and reduce water movement rates. Field equipment, such as heavy manure wagons, compacts wet soils, alters soil structure, and reduces water movement. Nutrient Losses During Collection and Storage Table 1 gives the nutrient content of swine manure as produced. Housing and waste handling systems affect the nutrient composition of wastes.