| Slightly-water-soluble felted and coated fertilizer with low cost and easy degradation was developed using a way of water as solvent and coated material.Applying experiments of performance test,indoor soil training test under different field capacity and spring rape pot,a study was made on nutrient release and biological effect of water-soluble felted and coated fertilizer.The results showed that this kind of water-soluble coated material was characterized as its compact contexture,uniform thickness,fine performance of water absorption and permeability and certain degree of biodegradability.Under 50%,60% and 70% field capacity,ammonium nitrogen content in soil with water soluble felted and coated fertilizer was in positive correlation to water content,and nitrate nitrogen content after 24 d was more than that with urea treatment.The output of spring rape with water-soluble felted and coated fertilizer treatment was higher than that with urea treatment under the condition of 50%,60% and 70% field capacity,and the difference was significant under 70% field capacity(P<0.05).Compared to urea treatment,water-soluble felted and coated fertilizer treatment increased the rape's content of Vc,but not the content of total nitrogen,nitrate or chlorophyll. |