Abstract
The rising prices of inorganic fertilizer have led farmers to consider alternatives. Composted animal manure is the most readily abundant alternative source of soil nutrients. Molding compost into pellets reduces the bulk and makes it more suitable for storage, transport, and mechanical application. I examined the effect of compost pelletization on the availability to plants of phosphorus (P) in the compost at various application rates in pot experiments using an andisol showing a high P sorption capacity. A mixture of cattle and poultry manure compost was pelletized by means of a disc pelleter and used as the sole source of applied P for komatsuna (Brassica campestris L.) and buckwheat (Fagopyrum esculentum Moench). The pelletized compost resulted in a superior P recovery rate by plants compared to that from ordinary compost. The P recovery rate from pelletized compost was 12.5% for komatsuna and 24.5% for buckwheat, while the corresponding values from ordinary compost were 8.6% and 15.9%, respectively. The P recovery rate from pelletized compost was comparable to that from superphosphate. Pelletization therefore appears to be beneficial to the phytoavailability of P in compost and may help avoid problems with P fixation in certain soils. Further investigations are necessary under various soil and cultivation conditions.