不同覆盖措施对旱区农田土壤酶活性及西瓜产量的影响

基于大田试验，研究了砂石+地膜覆盖，砂石覆盖，地膜覆盖3种旱区农田地表不同覆盖措施下的土壤酶活性及西瓜产量，以农田不覆盖（CK）为对照。结果表明：砂石+地膜覆盖在西瓜不同生育时期和不同土壤层次由于土壤水分条件的改善，可显著提高土壤酶活性，其中土壤脲酶活性提高了34.5%，碱性磷酸酶提高了13.0%，过氧化氢酶提高了29.5%，砂石覆盖次之（分别提高了31.4%，11.5%, 25.5%），地膜覆膜处理虽然也有提高土壤三种酶活性的效果，但作用甚微（仅0.9%，1.4%，2.9%）。对西瓜产量及商品率的影响，砂石+地膜覆盖、砂石覆盖处理与对照相比增产效果显著，分别增产50倍和30倍，地膜覆盖与对照相比增产7倍，但是商品率较低（2.16%）。表明在当地旱区农业生产中，砂石+地膜覆盖或砂石覆盖是抗旱、增产增收的有效措施。

Effect of different mulching methods on soil enzyme activity and watermelon production in farmland of arid areas

Soil enzyme activity and watermelon production were investigated by field experiment in arid areas. Four treatments were performed, gravel-sand and plastic film mulching (GFM), gravel-sand mulching (GM), plastic film mulching (FM), and bare farmland (CK). The results indicated that the GFM significantly increased activities of soil urease, alkaline, catalase phosphatase by 34.5%, 13.0%, and 29.5%, as compared with the CK, due to the improved the soil water content in different soil depth during different growth stages. GM treatment also showed significant effect, with those enzymes increased by 31.4%, 11.5%, 25.5%, respectively. In addition, minimal influence of FM was detected. Watermelon yield and its commercialization rate varied with the treatments. In comparison with the CK, the yield was significantly increased by 50 times and 30 times for GFM and GM respectively. By contrast, the commercialization rate was very low (2.16%). It was suggested that the combination of gravel-sand and plastic film mulching (GFM) or gravel-sand mulching (GM) should be employed to improve drought resistance and thereby watermelon yield for arid areas.