含N气体在长江三角洲地区农田与大气间交换的研究
文献类型：学位论文
| 作者 | 方双喜 |
| 学位类别 | 博士 |
| 答辩日期 | 2007 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 牟玉静 |
| 关键词 | NOX surface-exchange NH3 corn fields N2O vegetable fields 地气交换 农田 蔬菜地 |
| 其他题名 | Surface-exchange of N gases between agricultural fields and the atmosphere in the Yangtze Delta, China |
| 中文摘要 | 含N气体（NOX，N2O和NH3）对区域和全球环境具有重要影响。目前国际上已开展了大量关于含N气体在农田与大气间交换研究，并已认识到农作区域是大气中含氮气体的一种重要排放源。然而，我国在这方面的研究工作还相对薄弱，对农业活动导致的含N气体排放的认识也很不清楚。为此，我们选择了长江三角洲地区农田为研究对象，对含氮气体在该地区不同类型的农作物区域（冬小麦-水稻轮作农田和9种常见蔬菜地）与大气间的交换进行了为期三年的连续观测和研究。 研究发现长江三角洲地区冬小麦-水稻轮作农田是大气中NO的一个重要源。较强的NO排放出现在冬小麦主要生长期内，其间，土壤温度是决定NO在农田与大气间交换的决定性因素。该地区农田是NO2的一个汇，环境浓度是决定NO2在大气与作物农田间交换的关键因素。对于麦地而言，NO的排放是施加N肥挥发损失的主要形式，损失率为2.3%；而对于稻田而言，NH3排放为施加N肥挥发损失的主要形式，损失率为3.5%。利用平均排放强度乘以总播种面积方法估算了长江三角洲地区冬小麦农田和稻田对NO的年排放，分别达到35和3.5 Gg N，两者之和占全国土壤排放总量的5.9%。此外，我们也研究了木质素肥料对这些气体通量的影响，结果表明：在施加的N肥中添加木质素虽然能提高作物产量，但也刺激了农田对NO等气体的排放。 该地区蔬菜地是空气中NO的一个重要排放源，根据菜地NO通量平均值估计全年长江三角洲地区菜地对NO的排放总量为160 Gg N，明显强于正常粮食作物农田的排放，其总量占我国统计土壤排放总量的24.3%。平均而言，该地区菜地是大气中NO2的一个源，不同季节菜地对NO2的排放源于不同的机理。施肥能明显刺激农田对N2O的排放，我们估算该地区蔬菜地对N2O的年排放量大约为0.31Gg N。 |
| 英文摘要 | N gases (NOX, N2O and NH3) play important roles on regional and global environment. A lot of studies have been carried out to study the emissions of them from agricultural fields, which revealed that the agricultural fields were important sources. However, in China, there are a few studies related to those topics，and the contribution of agricultural area to the total amount of atmospheric N gases is still unknown. As a result, we continuously studied the surface-exchanges of these gases between different kinds of agricultural fields (winter wheat-rice rotation field and nine kinds of vegetable fields) and the atmosphere in the Yangtze Delta, China for about three years. The corn fields (winter wheat-rice rotation fields) in the Yangtze Delta acted as important sources of atmospheric NO. Large emissions occurred during the main growing periods of winter-wheat. From March to June, the soil temperature was the key factor affecting NO fluxes. These fields were sinks of atmospheric NO2. The atmospheric concentration of NO2 was the key factor controlling NO2 fluxes from the winter wheat field and rice field. As to the winter wheat field, NO emission was the main pathway of gaseous N losses (lose ratio, 2.3%). However, as to the rice field, NH3 emission (lose ratio, 3.5%) overrode the other two methods (NO, NO2). The total emission of NO in this area was estimated through the average emission intensity multiplying by the total cultivated area. And the results turned out to be 35 Gg N for winter wheat field and 3.5 Gg N for rice field, respectively. The total emissions from the corn fields accounted for about 5.9% of the yearly emissions in China. Additionally, we studied the effect of lignin fertilizers on the fluxes of these gases. We found that although the lignin fertilizer could enhance the total yields of corn, it greatly stimulated the emissions of NO from the corn fields. The vegetable fields acted as sources of atmospheric NO. We estimated the yearly emission of NO from the vegetable fields in the Yangtze Delta, China was 160 Gg N, which accounted for about 24.3% of the total soil emissions in China, and was much larger than that from the corn fields in this area. Generally, the vegetable fields acted as slight sources of atmospheric NO2. The emission of NO2 in different seasons might be from different mechanisms. The input of N fertilizer could stimulate the emission of N2O. We estimated the yearly emission of N2O from the vegetable fields in this area was about 0.31 Gg N. |
| 源URL | [http://ir.rcees.ac.cn/handle/311016/34947]  |
| 专题 | 生态环境研究中心_大气环境科学实验室 |
| 推荐引用方式 GB/T 7714 | 方双喜. 含N气体在长江三角洲地区农田与大气间交换的研究[D]. 北京. 中国科学院研究生院. 2007. |
入库方式： OAI收割
来源：生态环境研究中心
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