Hadas, Aviva, Inst of Soils and Water, Israel
Yosef, B.Bar, Inst of Soils and Water, Israel
Portnoy, Rita, Inst of Soils and Water, Israel

Manure pellets have the advantage of convenience in handling and application in the field, as well as combining basic fertilization and manure application when enriched with fertilizers. A reduction in NaHCO3-extractable P has been observed in soils amended with manure pellets compared with ground manure, particularly in superphosphate-enriched pellets. The objective of this study was to explain this reduction and to evaluate P fertilizers as manure-enriching materials. Fertilizer-enriched manures were incubated in soil for 7 and 60 d and their NaHCO3 extractability was compared with extractable P of fertilizers and unenriched manure. An index was suggested to evaluate the extractability of fertilizer P added to manures.