不同有机质含量农田土壤微生物生态特征

 【目的】土壤微生物在陆地生态系统中对土壤健康有重要的生物指示功能。比较东北不同有机质含量农田黑土间土壤微生物的生态特征，为维持或提高东北农田黑土的生态功能提供理论依据。【方法】于中国科学院海伦农业生态实验站，利用Biolog法与常规分析方法相结合测定空间移位（嫩江、北安、海伦、德惠、梨树）5年后5种不同有机质含量农田黑土在相同的气候条件下微生物生物量、微生物活性、群落结构及其代谢特性。【结果】土壤微生物量碳、基础呼吸、细菌数量随有机质含量的增加而增加，而真菌数量则随土壤有机质含量的增加而降低；且有机质含量最高的北安土壤与其它土壤之间的差异达到显著水平。平均色度变化表明，有机质含量最高的北安土壤中的微生物群落代谢能力高于有机质含量最低的梨树土壤；主成分分析表明，不同有机质含量农田黑土微生物群落对碳源的利用不同，有机质含量较高的北安和嫩江黑土中的土壤微生物对a-丁酮酸、腐胺、D,L-a-甘油的利用能力较高。土壤有机质含量最高的北安农田黑土微生物群落的丰度、多样性和均匀性指数最高。【结论】在外界环境一致的条件下，农田黑土有机质含量不同可影响土壤微生物群落的代谢功能及其代谢能力。

Research on Soil Microbial Ecology Under Different Soil Organic Matter Levels in Farmland

【Objective】 Soil microbe play an important role in the whole terrestrial ecosystem. Soil microbial properties are important bio-indicators of soil health. Therefore, soil microbial properties were studied under different soil organic matter levels in order to provide a theoretical basis for maintaining or improving soil ecological functions in Chinese mollisols farmland. 【Method】The soils with different soil organic matters (SOM) contents were removed from Bei’an, Nenjiang and Hailun in Heilongjiang province, Dehui and Lishu in Jilin province to Hailun agroecology experimental station in Heilongjiang province, then soil microbial properties such as microbial biomass, activity,  functional diversity of microbial community were investigated for five soils with different SOM contents by using Biolog and other universal analysis in the fifth year after soil spatial removal in Hailun agroecology experimental station. 【Result】 The results showed that soil microbial biomass C, soil basic respiration, and the amount of soil bacteria and fungi were increased with SOM increasing. Soil microbial properties in Bei’an with the highest content of SOM reached significant differences with the other soils. The average well color development values (AWCD) also indicated that the metabolizing capacity of microbe population in Bei’an was higher than that in Lishu with the lowest content of SOM. It was different for the carbon source used by microbe population under different SOM levels. The sensitive microbe C sources were α-butanone acid, putrescine, D, and L-α-glycerol which effectively used by soil microbe population in Bei’an and Nenjiang with higher SOM content. The soil of Bei’an with the highest SOM content had the highest diversity indices (H), richness indices (S), and evenness indices (E) of microbe populations. 【Conclusion】 These results showed that different SOM contents of black soils affected the metabolic functions of microbial community under the same external environmental conditions in farmland.