| 地膜覆盖对稻-油轮作农田CH4和N2O排放的影响 |
| 摘要点击 2373 全文点击 782 投稿时间：2016-12-28 修订日期：2017-06-05 |
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| 中文关键词 地膜覆盖 稻-油轮作 CH4 N2O 排放通量 全球增温潜势(GWP) |
| 英文关键词 plastic film mulching rice-rapeseed rotation CH4 N2O emission flux global warming potential(GWP) |
| 作者 | 单位 | E-mail | | 石将来 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400716 | 2473985448@qq.com | | 郝庆菊 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400716 | | | 冯迪 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400716 | | | 张凯莉 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400716 | | | 石孝均 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400716
国家紫色土肥力与肥料效益监测基地, 重庆 400716 | | | 江长胜 | 西南大学资源环境学院, 三峡库区生态环境教育部重点实验室, 重庆 400716 | jiangcs@126.com |
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| 中文摘要 |
| 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稻-油轮作农田为研究对象，采用静态暗箱/气相色谱法，对覆膜与常规（不覆膜）两种处理下稻-油轮作农田CH4和N2O的排放特征及影响因素进行了为期一年的原位观测.结果表明，两种处理下，CH4和N2O的排放均主要集中在各作物的生长前期，水稻季CH4和油菜季N2O的排放通量均具有较明显的季节变化；全年CH4的排放通量介于-0.45~1.90 mg·（m2·h）-1，N2O的排放通量介于-46.1~2040.7μg·（m2·h）-1.地膜覆盖提高了CH4和N2O排放总量，其中覆膜处理全年CH4排放总量为（27.22±4.48） kg·hm-2，相比常规处理（19.93±0.56） kg·hm-2提高了26.22%；覆膜处理N2O的年排放总量为（13.14±0.82） kg·hm-2，较常规处理下（11.27±2.77） kg·hm-2增加了16.6%.覆膜显著提高了油菜季土壤含水率，而对全年各作物季土壤温度（地下5 cm温度和地表温度）没有明显的影响.覆膜处理下油菜季CH4和N2O的排放与土壤含水率呈负相关，幼苗期达显著负相关；两种处理下，各作物季CH4和N2O的排放与土壤温度的相关性均很小.研究表明，地膜覆盖影响作物各生育期内CH4和N2O的排放规律，改变了作物各生育期内2种气体排放占全季排放量的比例，促进了稻-油轮作农田CH4和N2O的排放.在100 a时间尺度上，覆膜处理下全年排放的CH4和N2O所引起的综合GWP（CO2量）为4213.00 kg·hm-2，较常规处理3454.17 kg·hm-2提高了22.0%，表明覆膜不是一种有效的碳减排措施. |
| 英文摘要 |
| A field experiment was conducted in the Key Field Station for Monitoring of Eco-Environment of Purple Soil of the Ministry of Agriculture of China in the farm of Southwest University in Chongqing. Static opaque chamber and gas chromatography methods were used to study the effect of plastic film mulching on CH4 and N2O emissions characteristics from a rice-rapeseed crop rotation in situ for one year. The results showed that CH4 and N2O emissions are mainly concentrated in the early stages of the growth of each crop and there is a clear seasonal variation of CH4 emissions during the rice growing period and N2O in the rapeseed growing period. The CH4 flux changed from -0.45 to 1.90 mg·(m2·h)-1 and the N2O flux varied between -46.1 and 2040.7 μg·(m2·h)-1 over the entire year. Plastic film mulching was found to increase the total emissions of CH4 and N2 O, with the total CH4 emission of(27.22±4.48) kg·hm-2 over the entire year, which is 26.22% higher than that of the non-mulching treatment(19.93±0.56) kg·hm-2. The total amount of N2O emissions under film mulching treatment increased 16.6% from (11.27±2.77) kg·hm-2 under no mulching treatment to (13.14±0.82) kg·hm-2. The results analyzed for soil moisture and soil temperature showed that mulching significantly increased the soil moisture during the rapeseed season, while there was no obvious correlation with soil temperature (at depths of 5 cm and for the surface temperature) for each crop season. During the rapeseed growing season, CH4 and N2O emissions negatively correlated with soil moisture and has a significant negative correlation during the seedling period with film mulching treatment. Moreover, under the two treatments, the correlation between CH4 and N2O emissions and soil temperature was negligible. This study indicates that plastic film mulching impacts CH4 and N2O emissions at different growth stages of the crops, which changes the proportion of the emission of the two gases over the whole growth period, and promotes the emission of CH4 and N2O in the rice-rapeseed system. In the time scale of 100 years, the integrated global warming potentials (GWP) of CH4 and N2O emission under plastic film was a CO2 equivalent of 4213.00 kg·hm-2 compared with that under conventional treatment of 3454.17 kg·hm-2. Conventional emits 22.0% less CO2, indicating that plastic film mulching is not an effective measure for carbon sequestration. |
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