| Abstract: | Pulverized refuse fines (PRF) are the residual fine screenings from refuse-derived fuel plants after the removal of metals and oversize material from domestic refuse, and the extraction of the light fraction as fuel. It appears to be a potential soil amendment, but currently it is disposed of by landfilling. The glasshouse experiment described in this paper therefore evaluated its effectiveness as a soil amendment or soil material for plant growth.PRF had a slightly alkaline pH and was high in organic carbon and soluble salts. Unamended PRF supported significantly higher yields of ryegrass than PRF mixed with a sandy soil at 2 and 10% (w/w), and was comparable to that of sewage sludge and sludge-amended PRF. On the other hand, PRF supplemented with inorganic nitrogen or phosphorus resulted in better yields than PRF alone. Despite the high C/N ratio of PRF, nitrogen recovery in ryegrass suggested that mineralization was sufficiently high to allow adequate plant uptake and sustained plant growth, although there was initial inhibition. Tissue contents of zinc, copper and cadmium from pure PRF treatment were not excessive and were lower than those from sewage sludge.High rate applications of PRF, which are desirable from the viewpoint of disposal, should not cause environmental degradation. PRF is not as good as commercial fertilizers or potting media, but it can be an excellent soil substitute in horticulture and land reclamation. |
