Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 11/2/2003
Publication Date: 11/2/2003
Citation: SIKORA, L.J. COMPOST PHOSPHORUS AVAILABILITY TO FESCUE IN PHOSPHORUS DEFICIENT SOIL. AMERICAN SOCIETY OF AGRONOMY MEETINGS. 2003.
Technical Abstract: Nutrient management plans require that fertilizer equivalents of manures and composts be used in determining the total nutrient application to soils. In the past, composts were not considered fertilizers but only sources of organic matter. The P nutrient content of composts has not been studied as extensively as N, but with recent emphasis on P enrichment of waterways, more extensive studies are required for both manures and composts. A Codorus soil with less than 10 mg kg-1 Mehlich-3 extractable P was amended with poultry litter compost (PLC) or triple super phosphate (TSP) at rates of 0, 50, 100 and 150 kg P ha-1. Nitrogen was supplied to be uniform across all treatments taking into account the N mineralization rate of PLC. Fescue (Festuca arundinacea Schreb) was grown and harvested three times over 103 days. Yield of fescue was curvilinear related to rate of amendment, but yield was not affected by treatment source, poultry litter compost or triple super phosphate. Models describing yield changes with rate were different for TSP and PLC as yields increased more rapidly for TSP than PLC at low P additions, but decreased more rapidly than PLC had higher P rates. Phosphorus uptake was statistically the same for both treatments and a single quadractic equation describing P uptake with rate. These data indicate that PLC added to soils on a total P basis provided the same amount of fertilizer equivalents as TSP. Thus, if PLC is applied to soils at the N fertilizer rate for a crop, an excess of P fertilizer would result.