The application of css in soil as a nutritive amendment requires as a well understanding of dosage to avoid serious problem caused by css overdosing. Css supplementation for the nitrogen demand og crops can lead to excessive phosphorus in soil because of the low ratio of N:P in the biosolid compared with inorganic fertilizers (white and Collin,1982). Cheng et al.(2007) recommended that a dose of css < 20% can be uses as soil amendments to avoid the effect of soluble salts contents.