地膜覆盖对土壤微生物群落结构的影响

采用磷脂脂肪酸(PLFA)法测定了沈阳农业大学棕壤长期定位试验站地膜覆盖条件下土壤微生物磷脂脂肪酸图谱及群落结构。结果表明:在玉米苗期,长期施氮肥处理土壤覆膜后大部分脂肪酸含量都有所提高;施有机肥处理的土壤覆膜后脂肪酸的含量有降低的趋势;有机无机肥配合施用处理的土壤覆膜会增加真菌的含量,但却降低了其他脂肪酸的含量;在不施肥处理的土壤中,覆膜会使一些支链脂肪酸的含量降低。抽雄期,施有机肥的土壤覆膜后除单饱和脂肪酸含量有所下降外,其他脂肪酸都会提高;不施肥土壤覆膜处理双不饱和支链脂肪酸及放线菌标志性脂肪酸10Me18:0的含量会有所提高。成熟期,施氮肥的土壤覆膜处理大部分脂肪酸的含量降低;有机肥处理土壤中各种脂肪酸如:15∶0,a17∶0,i17∶0,i19∶0,18∶0,10Me18∶0含量覆膜高于裸地;有机无机配施处理土壤中17∶0,br17∶0,18∶0,18∶2w6,10Me18∶0含量覆膜处理高于裸地;对照土壤中i15∶0,16∶0,17∶0,a17∶0,18∶0,18∶2w6,19∶0含量覆膜高于裸地。另外,从脂肪酸的变化看出,覆膜处理土壤微生物群落整体结构发生了改变,没有表现出明显的种群优势。但是,尽管土壤的施肥处理不同,覆膜处理土壤微生物群落结构有一致化发展的趋势。

Soil Microbial Community Structure Responses to Mulching with Plastic Film on Brown Earth

In order to probe into the changes of soil microbial community under mulching with plastic film, the paper determined the soil microbial phospholipid fatty acid (PLFA) profiles and community structure with the methed of PLFA in the long-term located brown earth experiment site at Shengyang Agricultural University. The results were as the following: In seedling of corn, the contents of major PLFA almost advanced after mulching with plastic film in nitrogen fertilization treatment soil but decreased in manure treatment. The fungal enhanced after mulching with plastic film in the combination of organic and inorganic fertilization treatment, but the contents of other fatty acids declined, and mulching with plastic film made the contents of branch chain fatty acid decrease in no fertilization treatment soil. In heading of corn, the contents of most fatty acid increased except odd-saturated fatty acid after mulching with plastic film in organic fertilization treatment soil. The contents of double-unsaturated fatty acid, branch chain fatty acid and representative fatty acid of actinobacteria-10Me18∶0 all enhanced after mulching with plastic film in no fertilization treatment soil. In maturating of corn, the contents of major PLFA were lowed after mulching with plastic film in nitrogen fertilization treatment. The fatty acid of 15∶0,a17∶0,i17∶0,i19∶0,18∶0,10Me18∶0 in treatment, the contents of fatty acid of 17∶0,br17∶0,18∶0,18∶2w6,10Me18:0 in the combination of organic and inorganic fertilization treatment and the contents of fatty acid of i15∶0,16∶0,17∶0,a17∶0,18∶0,18∶2w6,19∶0 in no fertilization treatment increased after mulching with plastic film. The soil microbial community after mulching with plastic film has changed and has not dominant species community obviously, but the microbial community structure trended to identical develop despite of different fertilization treatments.