宁夏引黄灌区不同种植年限及方式温室土壤酶活性的变化特点

根据宁夏引黄灌区日光温室分布地区，采集了不同种植年限、不同种植方式温室表层土壤，测定了土壤脲酶、蔗糖酶、磷酸酶、过氧化氢酶活性，并研究了这4种土壤酶活性的变化特点．结果表明，温室土壤脲酶、蔗糖酶、磷酸酶、过氧化氢酶活性分别高于露地土壤230％，46．8％，24．0％和6．3％．轮作土壤酶活性明显高于连作土壤，土壤脲酶、蔗糖酶、磷酸酶和过氧化氢酶活性前者比后者分别提高28．1％，42．3％，6．9％和8．9％．在0～12a范围内，温室土壤酶活性随着种植年限的延长呈抛物线变化趋势，在种植6～8a前呈上升趋势，之后呈下降趋势．这一结果可为温室土壤的持续利用与科学管理提供理论依据．

Enzyme Activity Variations of Greenhouse Soils with Different Growing Manners in Different Times in Ningxia Irrigating Regions

Based on the distribution areas of the sunlight greenhouses in irrigating regions by Yellow River water in Ningxia, the topsoil samples（0--20 cm） in the greenhouses with different growing manners in different growing times were taken. The activities of urease, invertase, phosphatase and catatase in the greenhouse soils were determined, respectively. The four kinds of the soil enzyme activity variations were studied for the soil samples. The results showed that the activities of urease, invertase, phosphatase and catalase in the greenhouse soils were higher than that in the open fields,in which the activities of urease, invertase,phosphatase and catalase in the greenhouse soils increased by 230%, 46.8%, 24.0%, 6. 3%, respectively. The activities of these enzymes were higher in the rotation soils than that in the monocropping soils, the activities of urease,invertase, phosphatase and catalase in the soils increased by 28.1%, 42.3 %, 6.9%,8. 9%, respectively. The enzyme activities in the greenhouse soils varied with the growing times from 0 to 12 years in the form of parabolas. They were increased before growing 6--8 years and after that they were decreased as a whole. The results can provide a theory basis for the sustaining utilization and scientific management of the facility soils.