中文摘要：

通过在陇中黄土高原半干旱区设置的田间定位试验,研究了5种保护性耕作措施与传统耕作方式对旱地麦田土壤酶活性的影响。结果表明：不同耕作处理下过氧化氢酶活性均随耕作层的加深而递减;脲酶、碱性磷酸酶、蔗糖酶活性表现为三种翻耕处理（T,TS,TP）随土层的加深呈先增加后降低的趋势,而三种免耕处理（NT,NTS,NTP）随土层的加深而递减;与传统耕作（T）相比,免耕秸秆覆盖处理（NTS）下过氧化氢酶活性升高11.74%,脲酶活性升高17.60%,碱性磷酸酶活性升高43.99%,蔗糖酶活性升高40.22%;另外,就产量表现而言,免耕秸秆覆盖（NTS）是传统耕作（T）的1.68倍,统计分析差异显著（P〈0.05）。可见,在黄土高原西部旱农区实施免耕秸秆覆盖的保护性耕作措施,既有利于作物产量的提高,也可以改善耕层土壤酶活性。

英文摘要：

Based on conservation tillage experiment in Dingxi of Gansu, effects of conventional tillage and five conservation tillage patterns＇, namely, conventional tillage（T）, conventional tillage with stubble incorporating（TS）, no till with no stubble（NT）, no till with stubble retention（N TS）, conventional tillage with plastic film mulching（TP） and no till with plastic film mulching（NTP） on soil enzymatic activities and grain yield in the rainfed farming system were studied. The results showed that soil Catalase activity was reduced with the incensement of soil depth. The activities of Urease, Alkaline phosphates and Invertase in T, TS and TP treatments decreased from the soil profile of 0--5 cm to 5--10 cm and increased from 5--10 cm to 10--30 cm, while decreased in NT, NTS and NTP treatments from soil surface to deep soil layers. Compared with T treatment, NTS treatment can improve Catalase, Alkaline phosphatase and Invertase by 11.7%, 17.60% and 43.99%, respectively. For grain yield, it is the highest in NTS treatment, being 1.68 times higher than that in T treatment. Therefore, no till with stubble retention would not only improve grain yield, but also can improve soil enzymatic activities.