【作者】 黄立章；

【导师】 石伟勇；

【作者基本信息】 浙江大学 ， 植物营养学， 2004， 硕士

【摘要】 壳聚糖(Chitosan，简称CTS)是由甲壳素脱乙酰基得到的重要衍生物，是一种高分子阳离子多聚糖，它的性质独特，具有无毒、易成膜、良好的生物相容性和降解性好等特性，在农业、工业、医学、环境保护等部门有着广阔的应用前景。壳聚糖的前体甲壳素来源于甲壳类动物，甲壳素每年地球上自然生成量高达百亿吨，其产量可与纤维素匹敌，储量十分巨大。浙江是一个海洋大省，海岸线总长6，141公里，海洋资源极为丰富，据统计，全省每年废弃的虾、蟹甲壳就达10多万吨，若不及时妥善处理，不仅会对环境产生污染，而且也会造成甲壳资源的极大浪费，从另一方面来说，在浙江等沿海地区开发生产壳聚糖也就具有就有了资源优势。 对肥料包膜是实现养分控制释放的方式之一，但用树脂包膜不仅成本高，而且容易导致土壤的树脂污染，不利于农业的可持续发展。本研究拟利用壳聚糖作为包膜材料，研制出一种环保型的且有多功能的包膜尿素，并研究其对作物的肥效，为甲壳素的资源化利用和开发新型肥料提供新思路。本研究通过室内培养、盆栽试验，初步探讨了该包膜尿素的一些特性及其肥效，取得的主要结果如下： 1．通过大量的试验筛选和配制了壳聚糖为主包膜剂，并通过一定工艺研制成包膜尿素。同时探讨了包膜剂组成比例和浓度，包膜厚度，交联剂(醛类)用量等条件对包膜尿素性质的影响，为壳聚糖包膜尿素的工业化生产提供依据。 2．通过研究发现，壳聚糖包膜尿素(工艺2-0-3)堆密度降低，颗粒抗压强度提高。包膜尿素为吸湿量1.81g／cm~3，和普通尿素相差不大，因为包膜的两种物质都是亲水性物质，即使里面加了疏水剂，吸湿量相差也不大。包膜尿素的渗湿深度比普通包膜低得多，包膜尿素的湿保持容量也比普通包膜的尿素更高，约为后者的1.78倍以上，并具有更好的抗结块性。壳聚糖包膜尿素的pH降低，主要是因为壳聚糖包膜液是酸溶性所致。 3．通过室内土培试验发现，与普通尿素相比，施用该包膜尿素能够维持土壤后期氨态氮浓度高于普通尿素，硝态氮浓度更低。试验表明，施用壳聚糖包膜尿素能降低土壤的脲酶活性，提高过氧化氢酶活性；同时降低了土壤的EC值，但对土壤的pH影响不大。 4.对壳聚糖包膜尿素的无土淋溶和有土淋溶试验结果表明该包膜尿素比普通尿素释放缓慢，更能抗淋溶，减少渗漏损失。 5.对凡种植物病原菌的拮抗作用试验表明，壳聚糖包膜尿素对所提供的梨轮纹病菌(Physalospora pirieora Nose)、疫病病菌(Phytopthora sp.)、尖抱镰刀病菌(Fusarium axysporum)、水稻纹枯病菌(Pellieularia sasakii)、茄腐镰刀病菌(Fusarium solani)、芒果蒂腐病菌(B。tryodiplodla theobromae)具有抑制作用. 6.青菜施用壳聚糖包膜尿素，增产效果显著，产量比普通尿素增产15.41%。同时提高植株中N、P、K含量，增加青菜的Vc和叶绿素含量，降低了硝酸盐含量。收获后土壤的碱解氮含量比普通尿素高。在本试验中，发现在氮肥用量减少20%的情况下，与普通尿素相比，壳聚糖包膜尿素处理的产量、Vc等指标并没有降低。 7.菠菜施用壳聚糖包膜尿素，提高了产量，比普通尿素增产14.79%，达显著水平，同时也提高植株中的含氮量。试验结果显示，施用壳聚糖包膜尿素同样提高菠菜的Vc和叶绿素含量，降低了硝酸盐含量。产后测定结果还表明，施用壳聚糖包膜尿素不仅对土壤的pH影响不大，和普通尿素相比还降低了土壤中的EC值。更多还原

【Abstract】 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更多还原