【作者】 刘蕊；

【导师】 宋付朋；

【作者基本信息】 山东农业大学 ， 土壤学， 2010， 硕士

【摘要】 针对现代农业生产中氮肥的大量施用所造成的严重生态问题,研究包膜控释尿素的氨挥发损失、土壤氮素变化、对土壤微生物多样性的影响以及小麦的生长效应,阐明控释尿素的农学和生态效应,为控释尿素的推广应用和可持续农业的发展提供科学理论和实践依据。采用田间试验和室内化验分析相结合的方法,研究了控释尿素对土壤氨挥发、氮素养分和微生物多样性及小麦产量的影响,主要研究结果如下：1.与普通尿素相比,控释尿素能够有效推迟土壤氨挥发速率峰值的出现3-5天,降低土壤氨挥发速率峰值44.44%～69.51%、减少整个小麦生育期土壤氨挥发累积损失量39.31%～52.11%,树脂膜控释尿素减少氨挥发损失效果显著优于硫膜控释尿素,土壤氨挥发累积损失量比硫膜控释尿素降低了13.21%～21.08%。2.硫膜和树脂膜控释尿素在整个小麦生育期内能够维持耕层土壤较高的硝态氮、铵态氮和全氮含量水平,尤其是其释放高峰延迟到小麦拔节期之后,使土壤速效氮(硝态氮、铵态氮)含量持续升高有利于小麦攻穗,达到了氮肥后移的效果；降低了剖面下部土层中速效氮和全氮的含量,有效维持了剖面上部土层氮素水平,阻滞了氮素养分的淋溶损失；其中树脂膜控释尿素明显优于硫膜控释尿素。3.控释尿素提高了小麦近根区土壤微生物的功能多样性和活性,促进了小麦近根区养分的转化和循环,但随着小麦的生长,在持续维持小麦近根区土壤微生物活性上,树脂膜控释尿素作用强于硫膜控释尿素,而其多样性指数却略低。4.硫膜和树脂膜控释尿素的控制释放性能显著促进了小麦的株高、叶长、叶宽以及叶绿素含量等长势指标,且都能够提高小麦的穗数、穗粒数和产量,增产率达到13.10%～31.70%,树脂膜控释尿素增产率高出硫膜控释尿素2.72%～4.16%。控释尿素的氮素利用率达到48.93%～59.26%,树脂膜控释尿素的肥料效应贡献率最高。更多还原

【Abstract】 Modern agricultural production has caused severely environmental contamination by applying excessively readily available fertilizers in order to pursue high yielding. The effects of controlled release urea on soil ammonia volatilization, nitrogen nutrient, microbial diversity and wheat yield were researched to illustrate the agricultural and ecological effects of controlled released urea. This can provide theoretical supports for the application of controlled released urea and the development of sustainable agriculture.The field experiments and indoor chemical analyses were carried out to discus the effects of CRU on soil ammonia volatilization, nitrogen nutrient, microbial diversity and wheat yield. And the conclusions are as follows:1. Compared with urea, controlled released urea can postpone the appearance of the peak of SAV rate 3 to 5 days, decrease the peak value of SAV by 44.44%～69.51%, reduce the accumulative amount of SAV during wheat growth by 39.31%～52.11%. Compared with CRU coated by sulfur, controlled release urea coated by polymer can reduce the amount of SAV by 13.21%～21.08%.2. The amount of nitrate nitrogen, ammonium nitrogen, total nitrogen in top soil during the wheat growth can be maintained by CRU coated by sulfur or polymer, especially after the release rate postpone to the jointing stage of wheat, which can increase the content of available N (including NN and AN) persistently. In addition, CRU coated by sulfur or polymer can decrease the amount of available N and TN, maintain the content of N in upper profile soil and prevent the leaching loss of N nutrient. Moreover, The CRU coated by polymer can do these better than the CRU coated by sulfur.3. The CRU promotes the soil microbial diversity and activity, boost the nutrient transform and cycle rate in wheat rhizosphere. With the development of wheat, the CRU coated by polymer can maintain the microbial activity better than the CRU coated by sulfur. But in terms of soil microbial diversity index, it shows a reverse trend. 4. The controlled-release capability of CRU coated by sulfur or polymer increases the growing indexes significantly, such as the shoot height, length or width of leaf and chlorophyll. In addition, the CRU coated by sulfur or polymer can enhance the spike number, grain number and yields by 13.10% to 31.70%, and the increase production rate of the latter one is higher than the former one by 2.72% to 4.16%. What is more, the use efficiency of N applying CRU can reach from 48.93% to 59.26%, and the contribution rate of fertilizer of CRU coated by polymer is the highest.更多还原