The optimum combination program of N, P, and K in the basic fertilizer on the cold type turf was studied by using three factors saturated optimum design and gray game decision method.

This study general introduce the basic character of biogas liquid residue and summarize its recently application as mixture of feedstuff, fertilizer, seed Soaking, pesticide and so on.

This lesson chiefly describes the basic cases of patent application of fertilizer and the main problems existed in specifications and claims in current application documents.