黄瓜连作土壤及营养基质热处理的生物效应研究

Study on the Biological Effect of Heat Treated Cucumber Continuous Cropping Soil and Nutrition Medium

为明确黄瓜连作土壤和营养基质热处理的生物效应,以连作12茬黄瓜的土壤和营养基质为试材,分别设55℃和75℃2个处理温度,48 h和96 h 2个处理时间,热处理后采用塑料钵进行黄瓜苗期试验,研究土壤和营养基质热处理对黄瓜生长、土壤酶活性、土壤微生物区系和土壤养分的影响。结果表明,连作土壤和营养基质热处理后均明显促进了黄瓜的生长,减轻了连作障碍的发生;热处理显著提高了土壤中的过氧化氢酶、中性磷酸酶和蔗糖酶活性及细菌和放线菌数量,以及有机质、全氮、碱解氮、速效钾的含量,降低了真菌数量;但短时间55℃热处理提高了营养基质过氧化氢酶、中性磷酸酶活性和细菌及放线菌数量,降低了蔗糖酶和脲酶活性、真菌数量及全氮、碱解氮、速效钾的含量。综上所述,对连作土壤和营养基质进行热处理可有效减轻黄瓜连作障碍,其中以55℃、96 h的处理效果最明显。本研究为蔬菜连作营养基质修复再利用提供了理论基础和技术依据。

In order to unravel effects of heat treatment on biological effect of soil and nutritional medium, we heated soil and nutritional medium on which cucumber were successively planted for 12 times at 55 ℃ and 75 ℃ both for 48 h and 96 h, and then analyzed the characteristics of growth rate of cucumber, soil enzyme activities, soil microbial community and soil nutrients. The results showed that heat treatment significantly enhanced cucumber growth rate for both soil and nutritional medium, and alleviated the symptoms of continuous cropping obstacle; heat treatment significantly increased the activities of catalase, neutral phosphatase and sucrose, the number of bacteria and actinomycetes, and soil organic matter contents, total nitrogen, alkali-hydrolyzale nitrogen and available potassium, while decreased the number of soil fungi. However, short-time heat treatment at 55 ℃ increased the activities of catalase, neutral phosphatase and the amounts of bacteria and actinomycetes, while decreased the activities of sucrose and urease, the number of fungi, soil total nitrogen, alkali-hydrolyzale nitrogen and available potassium in nutritional medium. In conclusion, heat treatment can alleviate continuous cropping obstacle, especially for the treatment at 55 ℃ for 96 h. This study provided a theoretical and technical basis for restoration and reuse of the vegetable crop nutrient medium repair and recycled.