不同生长年限苜蓿栽培草地CO_2通量的初步研究  

CO2flux of alfalfa pasture with different ages

作　　者：庞莹莹[1] 邓波[1] 张英俊[1] 马学敏[1,2] 杨世超[1] 刘蒙[1] 

机构地区：[1]中国农业大学动物科技学院草业科学系,北京100193 [2]吉林农业大学园艺学院,吉林长春130118

出　　处：《草业科学》2011年第7期1239-1245,共7页Pratacultural Science

基　　金：农业部公益性行业(农业)项目(201003061);国家牧草产业技术体系资助

摘　　要：以种植第1年、第2年、第3年和第5年的紫花苜蓿阿尔冈金(Medicago sativa cv. Algonquin)为对象,通过研究其光合生理特性、土壤呼吸以及土壤有机碳的净通量等分析不同生长年限苜蓿草地碳通量的变化规律。结果表明,不同生长年限的苜蓿草地净光合速率呈单峰曲线,第1年和第5年在盛花期达到最大,分别为50和69μmol/(m2.s),第2年和第3年在结荚期达到最大值,分别为60和72μmol/(m2.s),与叶绿素a和b的含量不相关(P>0.05)。苜蓿草地土壤呼吸的动态变化呈不规则单峰曲线变化,6月24日达到最小值,7月达到最大值,平均值为第5年>第2年>第3年>第1年。土壤呼吸速率与土壤温度无明显的相关性(P>0.05);除第1年外,与土壤湿度显著相关(P<0.05),其中,第3年和第5年极显著相关(P<0.01)。第1年、第2年、第3年和第5年的苜蓿土壤有机碳的净通量分别为3.71、-1.71、12.17和12.53g/kg。Alfalfa pasture with 1, 2, 3, and 5 years was used to determine the effect of ages on CO2 flux of alfalfa pastures by measuring photosynthetic characteristics, soil respiration and net flux of soil organic carbon in the agro-pastoral ecotone of Northern China. This study indicated that the photosynthetic rate of alfalfa with different ages presented a single peaked curve, and the maximum of which was observed at the flowing stage in the first and the fifth year with the value of 50 and 69μmol/（m2·s）, respectively, while it was observed at the podding stage in the second and the third year with the value of 60 and 72 μmol/（m2 · s）, respectively. The photosynthetic rate had no significant correlation to chlorophyll a and chlorophyll b. The soil respiration of alfalfa pasture showed a irregular peak curve, with the minimum val- ue at June and the maximum at July, and followed the pattern with the fifth^the third, the second,the first year. The soil respiration of alfalfa pasture was not significantly correlated to soil temperature, however, was significantly correlated the soil moisture （P〈0.05） except the first year. The net fluxes of soil organic carbon of alfalfa pasture were 3.71, --1.71, 12.17 and 12.53 g/kg in the first, the second, the third, and the fifth year.

关 键 词：苜蓿草地 光合生理特性 土壤呼吸速率 土壤有机碳净通量 

分 类 号：S541.9[农业科学—作物学]