摘要： 分析了天津郊区不同种菜年限菜园土壤剖面碱性磷酸酶、脲酶、蔗糖酶及蛋白酶活性分布状况, 研究了不同施肥措施对土壤酶活性的影响。结果表明, 四种酶的活性均随剖面深度呈梯形减弱, 随种菜年限的延长而增高, 其中脲酶和碱性磷酸酶表现出明显的相关趋势, 菜园土壤通体酶活性水平明显高于一般旱田土壤, 菜园土壤酶活性与土壤有机质、全氮、全磷、有效磷呈显著或极显著正相关, 可以做为衡量土壤肥力水平的指标；有机肥与无机肥配合施用是增强土壤酶活性、提高土壤肥力的有效方法。

关键词: 菜园土, 酶活性, 土壤肥力, 土壤酶

Abstract: The distribution of enzyme activity of alkaline phosphatase, urease, invertase and proteinase in profiles of vegetable garden soils where vegetable plants were grown for different years in Tianjin suburbs was analysed. The effect of different fertilizer application on soil enzyme activity were studied. The results indicated that the activities of 4 enzymes decreased with the increase of soil depth, and increased with vegetable planting years. The urease and alkaline phosphatase appeared to have a clearly correlated tendency. The level of enzyme activity in the vegetable garden soil profile was higher than that of crop soil. The enzyme activity of vegetable garden soil showed positive correlation with soil organic matter, total nitrogen, total phosphorus and available phosphorus. So, enzyme activity could be used as an index for evaluation of soil fertility. The combined application of mineral and organic fertilizers was an effective method that may enhance enzyme activity and soil fertility.

Key words: Vegetable garden soil, Enzyme activity, Soil fertility