耕作方式与氮肥类型对稻田氨挥发、氮肥利用率和水稻产量的影响

Effects of tillage practices and nitrogen sources on NH_3 volatilization, nitrogen use efficiency and yield in paddy fields in central China

通过大田试验,设置常规翻耕(CT)、免耕(NT)两种耕作方式和不施氮肥(N0)、无机氮肥(IF)、缓释氮肥(SR)、有机无机氮肥配施(IFOF)4种施肥模式,研究其对稻田NH_3挥发、氮肥利用率和水稻产量的影响。研究结果表明:耕作方式显著影响NH_3挥发,而对氮肥利用率和水稻产量影响不大。与CT处理相比,NT处理NH_3挥发量显著提高了15.5%。氮肥施用显著提高了NH_3挥发、氮肥利用率和水稻产量。与N0处理相比,IF、SR与IFOF处理NH_3挥发量分别提高了150.2%、75.8%与137.8%。氮肥处理中IFOF处理具有最高的氮肥利用率。与IF处理相比,IFOF处理氮肥吸收利用率(NRE)显著提高了43.2%,氮肥偏生产力(NPFP)提高了16.9%,氮肥农学效率(NAE)提高了20.1%;与SR处理相比,IFOF处理NRE显著提高了38.3%,NPFP提高了22.1%,NAE提高了51.3%。IF、SR与IFOF处理较N0处理水稻产量分别提高了43.6%、30.0%与44.4%。本研究结果表明,翻耕下有机无机氮肥配施能有效地降低NH_3挥发,提高氮肥利用率和产量,但未来如何达到稻田NH_3与温室气体的同步减排需要进一步研究。

A field experiment was conducted to assess effects of tillage practices as conventional intensive tillage(CT)and no-tillage(NT)and N sources as no N fertilizer(N0),inorganic N fertilizer(IF),slow-release N fertilizer(SR)and inorganic+organic N fertilizer(IFOF)on NH3 volatilization,N use efficiency and yield in paddy fields in central China.Tillage practices significantly affected NH3 volatilization,but had no effects on N use efficiency and rice yield.Compared with CT,NT obviously increased NH3 volatilization by 15.5%.N fertilization significantly enhanced NH3 volatilization,N use efficiency and rice yield.Treatments of IF,SR,IFOF remarkably increased NH3 volatilization by 150.2%,75.8%and 137.8%,respectively,relative to N0.IFOF treatment showed the highest N use efficiency among N fertilizer treatments.Compared with IF treatment,IFOF treatment significantly enhanced NRE(N recovery efficiency)by 43.2%,NPFP(N partial factor productivity)by 16.9%and NAE(N agronomic efficiency)by 20.1%;IFOF treatment significantly enhanced NRE by 38.3%,NPFP by 22.1%and NAE by 51.3%relative to SR treatment.Rice yields under IF,SR and IFOF treatments were significantly 43.6%,30.0%and 44.4%higher than that under N0 treatment.Our results suggested that CT in combination with IFOF could effectively mitigate NH3 volatilization and increase N use efficiency and rice yield.However,further investigation is needed to discuss how to synchronously decrease NH3 and greenhouse gas emissions.