为明晰不同质地土壤微生物、胞外酶化学计量特征及其微生物养分限制特征的差异，对比分析东北地区农田黑土和风沙土全土、可溶性及微生物碳、氮、磷含量、胞外酶活性及其化学计量特征。结果表明，黑土全土、可溶性及微生物碳、氮、磷含量及碳氮比(C/N)和参与氮磷循环酶(NAG、LAP和ACP)活性显著高于风沙土，碳磷比(C/P)、氮磷比(N/P)、微生物量碳磷和氮磷比(MBC/MBP和MBN/MBP)、可溶性氮磷和碳磷比(DON/AP、DOC/AP)、参与碳循环酶(BG)活性则相反，表明风沙土有机质分解速率快于黑土，且黑土磷素有效性更高。黑土与风沙土向量角度小于45°，表明微生物代谢活动受到氮限制。相关性分析表明，黑土MBC在调节酶化学计量特征上发挥着关键作用，风沙土受土壤可溶性养分及其化学计量比的影响。

To clarify the differences in microbial and extracellular enzyme stoichiometric characteristics of different types of soils and their microbial nutrient limitation characteristics, the whole soil, soluble, microbial biomass carbon, nitrogen and phosphorus contents, extracellular enzyme activities and their stoichiometric ratios in black soils and aeolian sandy soil of Northeast China were studied. The results showed that the total soil, soluble, microbial carbon, nitrogen and phosphorus contents and carbon to nitrogen ratios(C/N) and activities of enzymes involved in nitrogen-phosphorus cycling(NAG, LAP and ACP) were significantly higher in the black soil than aeolian sandy soil, whereas carbon to phosphorus ratios(C/P), nitrogen to phosphorus(N/P), microbial biomass carbon to phosphorus and nitrogen to phosphorus ratios(MBC/MBP and MBN/MBP), soluble nitrogen and phosphorus and carbon to phosphorus ratios(DON/AP, DOC/AP), activities of enzymes involved in the carbon cycle(BG) were the opposite, indicating faster decomposition of organic matter in aeolian sandy soil than in black soil, and higher P effectiveness of the black soil. Both the black soil and aeolian sandy soil vector angles were less than 45°, suggesting that microbial metabolic activity was limited by N. Correlation analysis showed that MBC played a key role in regulating black soil changes in enzyme stoichiometry; whereas, in aeolian sandy soil was influenced by soil soluble nutrients and their stoichiometric ratios.

S513.062

中国科学院A类战略性先导科技专项“黑土粮仓”项目(XDA28080200)、国家自然科学基金项目(42371063)