控失尿素对稻田氨挥发、氮素转运及利用效率的影响

Effects of loss-controlled urea on ammonia volatilization,N translocation and utilization efficiency in paddy rice

通过田间试验,以普通尿素分次施用处理(CU)为对照,研究了控失尿素分次施用(LCUS)和一次施用(LCUB)对水稻田土壤氨挥发特征、水稻氮素营养状况、稻谷产量及氮肥利用效率的影响.结果表明:普通尿素分次施用、控失尿素分次施用和控失尿素一次施用条件下,生育期氨挥发总量占总施氮量的比例分别为15.8%、13.4%和19.7%.与普通尿素分次施用处理相比,控失尿素分次施用处理可降低土壤氨挥发损失量4.4 kg N·hm^(-2),降幅达18.0%,而控失尿素一次施用处理稻田土壤氨挥发总量却增加了7.2 kg N·hm^(-2),增幅达24.7%.与普通尿素分次施用处理相比,控失尿素分次施用处理的水稻叶片叶绿素、籽粒和茎叶氮含量与氮素积累量、稻谷产量均有不同程度提高,氮肥利用率显著提高了7.6%,但氮素转运量、转运率和对穗氮贡献率均显著降低,而控失尿素一次施用处理的水稻叶片叶绿素、籽粒和茎叶氮含量与氮素积累量以及氮肥利用率均显著降低,氮素转运量、转运率、对穗氮贡献率以及稻谷产量无显著差异.综上所述,控失尿素分次施用处理可以在保证稻谷稳产的同时,有效降低稻田土壤氨挥发损失,改善植株氮素营养状况,显著提高氮肥利用效率.

With the common urea split application （CU） as the control, a field experiment was conducted to examine the effects of loss-controlled urea by split application （LCUS） and loss-controlled urea by basal application （LCUB） on ammonia volatilization （NH3）, nitrogen （N） nutrition status, grain yield and N utilization efficiency in rice plants. The results showed that the ratio of NH3 volatilization loss to total N application were 15.8%, 13.4% and 19.7% under the conditions of CU, LCUS and LCUB treatments, respectively. Compared to CU, LCUS significantly reduced the NH3 emission by 4.4 kg N·hm-2, with a decrease of 18.0%, while the LCUB significantly increased the NH3 emission by 7.2 kg N·hm-2, which increased by 24.7%. Compared to CU, LCUS increased the chlorophyll contents of leaf, the N content and N accumulation of seed and straw and grain yield, and significantly increased the N recovery efficiency by 7.6%, while significantly reduced the amount of N translocation, apparent N translocation rate and the rate of contribution to N in spike, respectively. However, compared to CU, LCUB significantly reduced the chlorophyll contents of leaf, the N content and accumulation of seed and straw as well as N utilization efficiency, but the grain yield, the amount of N translocation, apparent N translocation rate and the rate of contribution to N in spike were not affected. In conclusion, LCUS could maintain stable production, as well as decrease NH3 emission, improve N nutrition status and increase N utilization efficiency in rice plants.