几种控释氮肥减少氨挥发的效果及影响因素研究

采用“静态吸收法”和“土柱淋溶法”、室内模拟试验，研究几种控释氮肥施入土壤后的氨挥发损失情况、N溶出速率、土壤脲酶活性及pH值变化的关系．结果表明，施氮450mg·kg^-1土时，3种控释氮肥氨挥发损失氮总量分别比普通尿素减少49．7％、28．0％和71．2％；施氮600mg·kg^-1土时，3种控释氮肥氨挥发损失氮总量分别比普通尿素减少34．6％、12．3％和69．9％．控释氮肥能显著降低土壤氨挥发量，减少因施肥而引起的大气环境污染．控释氮肥氨挥发量与不同氮肥引起的土壤脲酶活性、pH值、土壤中氮溶出速率密切相关．土壤的氨挥发总量与肥料在土壤中溶出总量的相关系数达到0．9533，在肥料施入的前期土壤氨挥发量同土壤脲酶活性、pH值的相关系数达到0．9533和0．9908。

Mitigation effect of several controlled-release N fertilizers on ammonia volatilization and related affecting factors

By using static absorption and soil column leaching methods, this paper studied the behaviors of several controlled-release N fertilizers in soil under laboratory conditions. The results showed that under the application rate of 450 mg x kg(-1), total ammonia volatilization from three controlled-release fertilizers decreased by 49.7%, 28.0% and 71.2%, respectively, in comparing with common urea. When the application rate was 600 mg x kg(-1), total ammonia volatilization decreased by 34.6%, 12.3%, 69.9%, respectively. Controlled-release fertilizers could markedly reduce total ammonia volatilization from soil and decrease environment pollution via fertilization. The results also indicated that total ammonia volatilization correlated significantly with soil urease activity, pH value and N leaching rate. The correlation coefficient between total ammonia volatilization and accumulated N leaching rate was 0.9533, and that between total ammonia volatilization and soil urease activity and pH value was 0.9533 and 0.9908, respectively.