秸秆生物反应堆对西瓜连作土壤微生物数量和土壤酶活性的影响

Effects of Straw Bio-reactor on Microorganism Population and Soil Enzyme Activity in the Watermelon Replant Soil

于西瓜大棚内分别对连作2、4、8年的土壤铺设玉米秸秆生物反应堆,同时设立各自相应的对照,定期测定各处理土壤养分含量、pH值、土壤微生物数量和土壤酶活性等,以评价秸秆生物反应堆修复连作土壤、改善土壤健康状况的效应。结果表明,使用秸秆生物反应堆1年或2年之后,连作土壤有机质含量、土壤微生物数量、土壤多酚氧化酶、蔗糖酶活性等显著提高。连作8年的土壤连续2年使用秸秆生物反应堆后,土壤有机质含量达到了2.41%;土壤细菌数量为1.65×108CFU/g、放线菌为3.12×106CFU/g、真菌为0.5×105CFU/g,土壤中丛枝菌根(AM)真菌孢子密度达到57个/50mL,分别是对照的2.2、5、1.44、1.36和3.2倍;多酚氧化酶和蔗糖酶活性则分别是对照的1.25和2.13倍。表明秸秆生物反应堆处理对修复连作土壤、改善土壤健康具有一定作用。

Corn straw bio-reactors were constructed in 2-, 4-, and 8-year replant soils grown with watermelon, while the 2-, 4-, and 8-year replant soils （without bio-reactors） were used as controls, respectively. The soil nutrient contents, pH, microorganism quantities, and soil enzyme activities were determined to evaluate the effectiveness of corn straw reactor’s improvement on soil health. Results showed that the soil organic matter content, microorganism quantities, and soil enzyme activities were increased significantly after 1- or 2-yearcorn straw bio-reactor treatments. In the 8-year replant soil treated with 2-year corn straw bio-reactors, the organic matter content reached 2.41%, the number of bacteria was 1.65 × 108 CFU/g, the actinomycetes was 3.12 × 106 CFU/g, the fungi was 0.5 × 105 CFU/g, and the abuscular mycorrhizal fungal spore density was 57/50 mL soil, which were 2.2, 5, 1.44, 1.36, and 3.2 times of their respective controls; while the polyphenol oxidase and sucrose invertase activities were 1.25 and 2.13 times of their controls, respectively. It was suggested that the corn straw bio-reactor be benefitial to rehabilitate replant soil.