摘要
以位于西南大学农业部重庆紫色土生态环境重点野外科学观测试验站内的冬水田(RF)、水稻-油菜轮作(RR)和水稻-儿菜轮作(RV)农田为研究对象,采用静态箱-气相色谱法对农田的温室气体的排放通量进行了为期一年的原位观测,其中采用静态暗箱技术观测CH4和N2O,静态明箱技术观测CO2.结果表明,不同轮作方式下CH4的年排放总量[以CH4计,kg·hm-2]RF(422.87±27.1)> RR(132.05±23.11)> RV(50.91±3.83),其中RV与RR处理较RF处理CH4排放量有明显下降(P<0.05);N2O的年排放总量[以N2O计,kg·hm-2]依次为RV(21.38±6.51)> RR(20.02±5.23)> RF(0.48±0.02),RV和RR处理N2O的排放总量均显著高于RF(P<0.05);CO2的年净排放总量[以CO2计,t·hm-2]为RR(-55.43±5.04)> RV(-29.1±3.00)> RF(-14.08±1.81),RV和RR处理CO2的吸收量显著高于RF处理(P<0.05).在100a时间尺度上,全年排放的CH4、N2O和CO2所引起综合GWP(以CO2计,t·hm-2)为RR(-46.43)> RV(-22.01)> RF(-2.11),表明冬水田转变为水旱轮作系统后能显著提升农田生态系统的增汇效果,相比于RV处理,RR处理增汇效果更好,即在西南地区水稻-油菜轮作农田在生态系统增汇上是一种最有效的轮作方式.
A field experiment was conducted at the Key Field Station for Monitoring Eco-environment of Purple Soil of the Ministry of Agriculture of China in the farm of Southwest University, Chongqing. The static chamber and gas chromatography method was used to study the effect of the cropping systems on greenhouse gases from rice-fallow (RF), rice-rapeseed rotation (RR), and rice-brussel mustard rotation (RV) cropland in situ for a year. An opaque chamber was used for CH4 and N2O observations and a transparent chamber was utilized for CO2 observations. The results show that the annual cumulative CH4 emissions from different crop rotations were (CH4, kg·hm^-2) RF (422.87±27.1) > RR (132.05±23.11) > RV (50.91±3.83). The RV and RR were significantly lower than RF (P<0.05). The annual cumulative emissions of N2O[N2O, kg·hm^-2] were RV (21.38±6.51) > RR (20.02±5.23) > RF (0.48±0.02). The RV and RR were significantly higher than RF (P<0.05). The annual net cumulative emissions of CO2 were (CO2, t·hm^-2) RR (-55.43±5.04) > RV (-29.1±3.00) > RF (-14.08±1.81). The RV and RR were significantly higher than RF (P<0.05). At the time scale of 100 a, the integrated global warming potentials (GWP) of CH4, N2O, and CO2 were (CO2, t·hm^-2)RR(-46.43) > RV(-22.01) > RF(-2.11), indicating that converting flooded paddy fields to paddy-upland crop rotation systems notably increases the potential increment of carbon sinks. Compared with RV, RR has a better effect, which suggests that rice-rapeseed rotation is the most effective measure for the escalation of carbon sinks of ecosystems in the southwestern area.
作者
冯夕
江长胜
彭小乐
李彦沛
郝庆菊
FENG Xi;JIANG Chang-sheng;PENG Xiao-le;LI Yan-pei;HAO Qing-ju(Key Laboratory of Eco-environments in Three Gorges Reservoir Region,Ministry of Education,College of Resources and Environment,Southwest University,Chongqing 400716,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2019年第1期392-400,共9页
Environmental Science
基金
国家自然科学基金项目(41275160
40975095)
中央高校基本科研业务费专项(XDJK2015A013)
