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本文对旱地苜蓿地与小麦连作土壤剖面酶活性的分布特征进行研究,同时分析了不同施肥条件下冬小麦生育期酶活性的变化。苜蓿连作系统CK、P、NPM处理土壤剖面(0～200cm)酶活性分析表明:不同施肥处理土壤酶活性的剖面分布状况为:耕层到底层急剧降低,不同施肥对其深层分布影响不明显,施NPM在一定程度上增加了底层土壤酶活性,但数学统计CK、P、NPM三处理之间差异未达显著水平。过氧化氢酶活性在整个剖面较高,随着剖面深入降低的不多,而蛋白酶、脲酶、碱性磷酸酶、蔗糖酶活性随剖面深入急剧降低;冬小麦连作土壤酶活性剖面分布特征与苜蓿连作一致,但施肥对20～40cm土层酶活性有一定的影响。过氧化氢酶活性随冬小麦的生长而增大,碱性磷酸酶活性生育期变化与土壤有效磷生育期变化有密切关系,而其余两种酶生育期变化规律不明显。
In this paper, the distribution characteristics of soil enzyme activities under continuous cropping of alfalfa and wheat in dryland were studied, and the changes of enzyme activities during the growth of winter wheat under different fertilization conditions were also analyzed. The enzymatic activities of soil profiles (0 ~ 200cm) under CK, P and NPM treatments in alfalfa continuous cropping system showed that the profiles of soil enzyme activities under different fertilization treatments were as follows: the top layer decreased sharply and the effect of different fertilization on the depth distribution was not obvious, NPM application increased soil enzyme activity to a certain extent, but there was no significant difference among the three treatments of CK, P and NPM. The activity of catalase was higher in the whole section and less in depth with the profile, while the activities of protease, urease, alkaline phosphatase and invertase decreased sharply along with the profile. However, fertilization had a certain effect on the enzyme activity in the soil layer of 20-40 cm. The activity of catalase increased with the growth of winter wheat. The change of alkaline phosphatase activity during the growth period was closely related to the change of soil available P during the growth period, while the other two enzymes did not change significantly during the growth period.