免耕对潮土不同粒级团聚体有机碳含量及微生物碳代谢活性的影响  

EFFECTS OF NON-TILLAGE ON CONTENT OF ORGANIC CARBON AND MICROBIAL CARBOLIC METABOLISM OF SOIL AGGREGATES IN A FLUVO-AQUIC SOIL

作　　者：戴珏[1,2,3] 胡君利[1,2] 林先贵[1,2] 朱安宁[1] 尹睿[1,2] 张华勇[1,2] 王俊华[1,2] 

机构地区：[1]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,南京210008 [2]中国科学院南京土壤研究所-香港浸会大学土壤与环境联合开放实验室,南京210008 [3]中国科学院研究生院,北京100049

出　　处：《土壤学报》2010年第5期923-930,共8页Acta Pedologica Sinica

基　　金：国家自然科学基金青年科学基金项目(40801090);中国科学院知识创新工程领域前沿项目(ISSASIP0703);中国科学院知识创新工程重要方向项目(Kzcx2-yw-408);中国科学院知识创新工程重大项目(Kscx1-yw-09-05)资助

摘　　要：利用中国科学院封丘农业生态国家实验站玉米-小麦轮作免耕定位试验平台,研究不同耕作方式对潮土不同粒级团聚体的分布、有机碳含量及微生物群落碳代谢活性的影响。结果表明,与传统翻耕处理相比,免耕潮土中大于250μm粒级团聚体显著增加(p<0.05),50～2μm粒级团聚体显著减少(p<0.05),250～50μm和小于2μm两个粒级团聚体没有明显变化;大于250μm和250～50μm两个粒级团聚体有机碳含量显著升高(p<0.05),50～2μm和小于2μm两个粒级团聚体有机碳含量没有明显变化,250～50μm粒级取代50～2μm粒级成为对土壤有机碳总量贡献最大的团聚体。BIOLOG测试结果表明,免耕和翻耕两种措施下不同粒级团聚体微生物群落碳代谢特征存在明显差异,且免耕处理250～50μm和小于2μm两个粒级团聚体微生物群落碳代谢活性显著低于翻耕处理(p<0.05)。结果显示,免耕有利于小粒级团聚体向大粒级团聚体方向聚合,大于50μm粒级团聚体固持的有机碳增多,其中持碳最多的250～50μm粒级团聚体的微生物碳代谢活性下降,故土壤有机碳稳定性升高。A field experiment is carried out to evaluate effects of non-tillage on distribution,content of organic carbon,and microbial carbolic metabolism of soil aggregates in a fluvo-aquic soil under a cropping system of corn-wheat rotation in the Fengqiu National Agro-Ecological Experiment Station,China.The250 μm fraction of aggregates in the soil was significantly higher（p0.05） under non-tillage than under conventional tillage,while the 250～50 μm fraction did not vary much between different tillage methods,and the contents of organic carbon in these two fractions were higher under no-tillage.The 50～2 μm fraction was significantly lower（p0.05） under no-tillage than under conventional tillage,while the2 μm fraction showed no much difference between tillage methods,and the organic carbon in these two fractions did not either.The increase in the 250～50 μm fraction and the resultant decrease in the 50～2 μm fraction made the former ranking first in contribution to the total organic carbon in the soil.BIOLOG analysis indicates that the two treatments,non-tillage and conventional tillage,differed significantly in carbolic metabolism of soil microbial communities in various particle size fractions,with the former being obviously lower than the latter in the 250～50 μm and2 μm fractions.All demonstrate that non-tillage favors congregation of small particles into macroaggregates and increases the content of organic carbon in the〉50 μm fraction,while microbial carbolic metabolism in the 250～50 μm fraction weakens thus leading to higher stability of organic carbon in the soil.

关 键 词：免耕 潮土 团聚体 有机碳 微生物碳代谢活性 

分 类 号：S152.4[农业科学—土壤学] S154.3[农业科学—农业基础科学]