稻麦轮作体系养殖肥水灌溉对产量、氨挥发和氧化亚氮排放的影响

Effect of Sewage Irrigation on Crop Yield, Ammonia Volatilization and Nitrous Oxide Emission in Rice-wheat Rotation

稻麦轮作体系进行养殖肥水灌溉可能导致氮（N）素的氨挥发（NH3）和氧化亚氮（N2O）排放增加。本文通过土柱模拟试验，定量评价了稻麦轮作体系推荐施N量（稻季225kg／hm^2，麦季150kg／hm^2）下，不同N浓度养殖肥水灌溉对水稻、小麦籽粒产量以及NH3挥发和N2O排放的影响。试验处理为：①无N检出的清水灌溉（CK），②低N浓度肥水灌溉（SI-L），③中N浓度肥水灌溉（SI-M）和④高N浓度肥水灌溉（SI-H）。稻季结果表明，NH3挥发与N2O排放量随灌溉肥水N浓度的提高而增加，其决定系数僻。）可达0．895与0．998。与清水对照相比，不同N浓度的肥水灌溉使NH3挥发增加19．7％～40．8％；SI-H处理N2O排放显著增加68．8％；不同N浓度肥水灌溉没有显著增加水稻产量。麦季结果亦表明，NH3挥发与N2O排放量随灌溉肥水N浓度的提高而增加，其决定系数（R^2）可达0．939与0．980。与清水对照相比，SI—H处理使NH3挥发显著增加20．2％；SI-M与SI-H处理N2O排放分别显著增加64．9％和120．3％；SI—H处理小麦产量显著提高46．7％。利用稻田生态系统消纳养殖肥水中N时，须考虑肥水灌溉导致的NH3挥发和N2O排放所造成的环境影响，合理地进行水肥调控。

Sewage irrigation in rice-wheat rotation likely lead to more nitrogen （N） loss via ammonia （NH3） volatilization and nitrous oxide （N2O） emission. A stimulated lysimeter study was conducted to evaluate the impacts of sewage irrigation with different nitrogen （N） concentration irrigation on NH3 volatilization, N2O emission and crop yield. The four treatments received equal optimal N input （225 kg/hm^2 in rice season and 150 kg/hm^2 in wheat season from urea fertilizer were 1） clean water irrigation as the control （CK）, 2） sewage irrigation with low N concentration （SI-L）, 3） sewage irrigation with medium N concentration （SI-M） and 4） sewage irrigation with high N concentration （SI-H）. Results in rice season showed that NH3 volatilization and N2O emission increased with the N concentration of irrigated sewage, and the determination coefficient （R^2） were 0.895 and 0.998, respectively. Sewage irrigation significantly increased the NH3 volatilization by 19.7% - 40.8% compared with the control, and the SI-H treatment significantly increased the N2O emission by 68.8%. Sewage irrigation did not increase the rice grain yield. Data in the wheat season suggested that NH3 volatilization and N2O emission also increased with the N concentration of irrigated sewage, and the determination coefficient （R2） were 0.939 and 0.980, respectively. Herein, 20.2% higher NH3 volatilization compared with the control was measured in the SI-H treatment. The SI-M and SI-H treatments significantly increased the N2O emission in wheat season by 64.9% and 120.3%, respectively. The SI-H treatment significantly increased the wheat production by 46.7%. The results suggest that NH3 volatilization and N2O emission must be considered when sewage irrigation was occurred in paddy field and more rational water and N fertilizer management should be adopted when paddy soil was explored to treat sewage water.