中文摘要：

灌溉对农田温室效应与碳足迹贡献产生重要影响.本文采用静态暗箱-气相色谱法对关中平原小麦-玉米轮作（2014-2015年）农田温室气体（CO2、CH4和N2O）排放通量进行了监测,并用净增温潜势（NGWP）和碳足迹两个指标评估不同灌溉量对关中平原农田温室效应、作物生产碳足迹的分布和构成的影响.试验在作物关键需水期（冬小麦越冬期和拔节期、夏玉米出苗期和拔节期）设置W0（0 mm）、W120（120 mm）、W180（180 mm）、W240（240 mm）4个处理.结果表明：与W0处理相比,W120、W180、W240处理下小麦产量分别增加了31.3%、44.3%、33.7%,玉米产量分别增加了9.9%、22.6%、33.8%;CO2的年际排放总量分别增加了22.2%、24.3%、15.1%,N2O的年际排放总量分别增加了18.6%、67.8%、91.5%,但CH4的年际吸收总量分别降低了51.7%、79.6%、97.8%;NGWP分别增加了20.1%、31.6%、31.4%.W（120）处理下碳足迹较W0处理降低了19.1%,但W（180）、W（240）处理与W0处理相比无显著性差异;W（120）、W（240）处理单位产量碳足迹较W0处理分别增加了44.5%、23.3%,而W（180）处理与W0处理无显著性差异.综合考虑不同灌溉量的经济效应和环境效应,180mm的灌水量更有利于关中平原小麦-玉米轮作系统的节水及固碳减排.

英文摘要：

Irrigation can influence greenhouse gas （GHG） emission and carbon footprint in agricul- tural production. In this study, annual GHG emissions （including CO2, CH4, and N2O） were monitored with static opaque chamber and gas chromatography from a wheat-maize rotation system under different irrigation treatments in the Guanzhong Plain of China during 2014-2015. A total of four different irrigation treatments were conducted, e.g. W0, W120, W180, and W240, where the subscripts represented the irrigation amounts in mm. Net global warming potential （ NGWP ） and carbon footprint were used to evaluate the influence of different irrigation amounts on GHG emission and composition of carbon footprint of crop production. Compared with treatment W0, wheat yield of treatments W120, W180, and W240 increased by 31.3%, 44.3% and 33.7%, while corn yield increased by 9.9%, 22.6%, and 33.8%, respectively. Similarly, annual CO2 emission increased by 22.2%, 24.3% and 15.1% and annual N2O emission by 18.6%, 67.8%, and 91.5%, respectively, while annual CH4 absorption decreased by 51.7%, 79.6% and 97.8%, respectively. The values of NGWP increased by 20.1%, 31.6%, and 31.4%, respectively. The carbon footprint of treatment W12o was 19.1% lower than that of W0, while W180 and W240 showed no significant difference. Treatments W120 and W240 increased carbon footprint per unit crop yield by 44.5% and 23.3%, respectively, while W180 showed no significant difference. Considering both the economic and environmental effects of different irrigation amounts, we recommend the irrigating amount of 180 mm for the wheat-maize rotation system in the Guanzhong Plain of China for the purposes of water saving and carbon sequestration.