中文摘要：

通过对不同施肥处理的免耕土壤酶活性和CO2排放通量测定分析,研究北方农牧交错区施肥对旱作免耕农田土壤酶活性、CO2排放量的影响及其相互关系,为提高土壤质量、实现固碳减排和可持续利用提供理论依据。结果表明：免耕施肥土壤酶活性和CO2排放通量高于不施肥处理;氮肥对脲酶、碱性磷酸酶、蔗糖酶活性和CO2排放通量的增加影响最大,其次是磷肥,钾肥最小;过氧化氢酶活性的增加受钾肥影响最大,磷肥次之,氮肥最小;氮磷或氮磷钾肥配施更能增加土壤酶活性和CO2排放通量,单施钾肥土壤过氧化氢酶活性高于氮磷肥配施。蔗糖酶和脲酶活性与土壤CO2排放量呈显著正相关,碱性磷酸酶和过氧化氢酶与土壤CO2排放量之间相关性不显著。

英文摘要：

Soil enzymatic activities and CO2 emission of no-tillage lands with different treatments of fertilizers was determined,analysed and estimated for their effects on soil enzymatic activities and CO2 emission under no-tillage lands in farming-pastoral zone of northern China and their correlations.Valuable data were provided for improving soil quality,enhancing farmland carbon sequestration,reducing CO2 emission and conducting sustainable utilization in dry land region.The results showed： the soil enzymatic activities and CO2 emission in the fertilizer treatments were higher than those from the no-fertilizer treatment under no-tillage.The increased activities of Alkali-phosphates,Ivertase and CO2 emission was mostly influenced by N-fertilizer,followed by P-fertilizer and K-fertilizer while the increased Catalase activities were mainly affected by K-fertilizer.The soil enzymatic activities and CO2 emission was further enhanced by the combined uses of NP-fertilizer or NPK-fertilizer.However,K-fertilizer treatment,compared to N-P fertilizer treatment,showed a better increase on Catalase activity.Conclusively,a highly positive correlation existed between soil CO2 emission and Ivertase and Urease activity while Alkali-phosphates and Catalase activity do not correlate CO2 emission.