| Chitosan, a macromolecular polysaccharide derived from deacetyl group from chitin, is widely used in agriculture, industry, medicine, and environmental protection field, because of its special characters, such as innocuity, film-forming easily, good biologically compatiblity, and easy degaradation. Precursor of chitosan is the side production of crustacean. Ten billion of tons of chitosan are produced on the earth every year. Zhejiang, a big sea province having a 6,141 km long coastline, is abundant in sea resource. More over 100 thousand tons of chitosan are produced in Zhejiang province every year. This may be the big environmental problem if chitosan cannot be used effectively. In another hand, this also shows that the prospect of development and production of chitosan is very good hi Zhejiang province.Fertilizer was coated with membrane, which is a way to control the release rate of nutrient from fertilizer. In present paper, hi order to make a new way to turn chitosan to a resource and to develop a new fertilizer, chitosan was used to coat urea to produce a new slow-released urea. In order to characterize the new urea and illustrate the effect of the new urea on pakchoi and spinach, incubation and pot experiments were conducted. The results showed that:1 .According to the characters of CTS and Nalg, two lands of liquid for coating were confected and effects of different proportions of them on dissolving time of Cts-coated urea were studied. The effect on stability of membrane and dissolving tune of Cts-coated urea of chitosan and sodium alginate solution with different mach ratio was found, hi the same condition, the ratio 1:1 was the best, with the most stable membrane and the biggest ratio of cover to core. The phenomena were also found that dissolving time become long with the increase of thick of membrane, hi present study, the dissolving time was also affected by amount of glutaraldehyde. The dissolving time prolonged with the increasing amount of glutaraldehyde.2.Pile density of urea coated with chitosan decreased. The value of granular compression strength of coateded urea increased from 35.59 to 48.92, with the increase of 37.45%. Hygroscopic capacity of Cts-coated urea is the same as urea, withthe value of 1.81 g cm-3. This may be the reason that two hydrophilous materials forming membrane were used. The seepage-wet depth of Cts-coated urea was less than urea and wet hold capacity of Cts-coated urea was about 1.78 fold high than that of urea. Cts-coated urea had better anti-agglomeration than urea and lower pH because of the acid dissolving of CTS.3.Studies showed that the content of NH4-N in soil treated with Cts-coateded urea was much higher than that of soil treated with urea and the content of NO3-N in so was less than that of soil treated with urea. During late period,also debasing urease activity in soil, increasing catalase activity, lowering the value of EC, little effect on pH were found.4.The results of leachine experiment with soil and without soil showed that release of nitrogen of coated urea in soil is lower than that of urea, better anti-leaching, and less loss of nitrogen.5.It was found that the extraction solution of Cts-coated urea could inhibit the growth of Physalospora piricora Nose, Phytopthora sp., Fusarium axysporum, Pellicularia sasakii, Fusarium solani, and Botryodiplodia theobromae.6.Experiments of pakchoi showed that yield of pakchoi increased with the increase of 15.41%. The content of N, P, K of pakchoi treated was higher that of pakchoi treated with urea. The use of Cts-coated urea increased the content of Vc and chlorophyll of pakchoi, higher than that of pakchoi treated with urea, and decreased plant nitrate concentration. However, content of NH4-N in soil treated with Cts-coated urea was much higher than that of soil treated with urea after harvest. In addition, yield of pakchoi treated with coated urea, and Vc content of pakchoi were the same as urea with 20% of amount of urea.7. The results of experiment on spinach were the similar with that on pak...
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