黑土母质熟化过程微生物群落碳源代谢特征

东北黑土区由于表土丧失,母质裸露等问题,严重威胁粮食生产和生态环境,通过揭示母质肥力形成过程中微生物群落的碳源利用特征可以让人们更好的理解肥力形成过程中相关微生物过程。以海伦农田生态系统国家野外科学观测研究站长期定位试验为材料,研究母质不同熟化过程下微生物群落碳源代谢特征,结果表明:苜蓿草熟化过程(PAfl)、农田化肥配施有机物熟化过程(PCS+F+OM)可培养微生物数量最多。自然熟化过程(PNat)、苜蓿草熟化过程、农田化肥农产品全循环熟化过程(PCS+F+BM)、农田化肥加有机肥配合型熟化过程可以将微生物活性提高到常规农田黑土的水平。不同熟化过程下微生物群落对单个碳源的利用不同。主成分分析表明自然熟化过程、农田化肥投入熟化过程(PCS+F)、农田化肥农产品全循环熟化过程、农田化肥加有机肥配合型熟化过程与常规农田黑土微生物代谢特征类似。研究表明不同母质熟化过程通过影响微生物群落结构导致对各个碳源的利用发生变化,最终改变了整体碳源代谢特征。

Microbial metabolic characteristics of carbon in the black soil parent material maturation process

The northeastern region of China represents the country''s largest commodity grain base. The Mollisols present in this northeastern region are very suitable for farming. However, the loss of top layer Mollisols and exposure of parent material have severely threatened the ecological environment and national food security in northeastern China. The soil microbial biochemistry process is the engine required for the reconstruction for soil fertilizers. Thus, it is important to characterize the pattern of carbon utilization by soil microbial communities during the parent maturation process to understand how microbial processes contribute to soil fertility. This study focuses on the carbon utilization pattern of soil microbial communities under different long-term maturing treatments at the national observation station of the Hailun Agroecology System. The results showed that Parent-Alfalfa (PAlf), Parent Corn-Soybean+Fertilizer+Biomass cycle (PCS+F+BM), and Parent Corn-Soybean+Fertilizer+Oganic Matter (PCS+F+OM) treatments contained the highest number of microorganisms. Parent-Natural (PNat), PAlf, PCS+F+BM, and PCS+F+OM treatments increased microbial activity to the level recorded under conventional farmland treatment. Different maturing process treatments produced different carbon utilization patterns in the microbial community. In all treatments, the highest utilization rate of the carbon source was carbohydrate. Principal component analysis indicated that the microbial metabolic characteristics under PNat, Parent-No Fertilizer (PCS-F), PCS+F+BM, and PCS+F+OM processes were similar to that those under Stander Soil Corn-Soybean+Fertilizer (SCS+F) treatment. We conclude that the change in microbial community structure under different maturing processes caused variations in the carbon utilization pattern, which ultimately influenced the metabolism characteristics of the overall carbon sources.