以西瓜和草莓连作病土为研究对象，设置不同处理时间（3、4、5、7周）、处理温度（10、20、30、40℃）、含水量（80%和100%田间最大持水量、淹水）以及物料类型（稻草、稻草+牛粪、稻草+铁粉）的强还原土壤灭菌（reductive soil disinfestation，RSD）处理，通过冗余分析和随机森林分析探讨RSD对不同土壤类型的改良效果及其共性影响因子。结果表明：与对照相比，RSD处理能显著降低两种土壤的电导率和提高土壤pH，且能有效减少土壤真菌/细菌比、尖孢镰刀菌数量及其在真菌中的占比。然而，各因素RSD处理间的土壤性状也呈显著差异，其中pH、电导率以及杀菌效果的整体变化幅度分别为6.48~8.64、0.15~0.22 mS/cm及0.6%~99.9%。RSD在处理温度高于10℃且处理时长为3周时可显著提高土壤pH；在淹水处理时土壤盐渍化去除效果最佳；在处理温度40℃条件下，尖孢镰刀菌的杀灭效果于两种土壤中均达99.7%以上。相关性分析进一步表明，处理温度与RSD处理后的土壤pH和微生物性质相关性最高，且各因素对RSD处理杀菌效果的重要性排序为：温度>时间>物料类型>含水量。综上，温度是影响RSD处理对不同连作病土改良效果的主要因素。

In this study, the watermelon and strawberry continuous cropping soils were used to conduct various reductive soil disinfestation (RSD) treatments, involving different incubation time (3, 4, 5 and 7 weeks), temperature (10, 20, 30 and 40℃), irrigating conditions (80%, 100% of the maximum field capacity and flooding) and organic material types (straw, straw+crow dung and straw+iron powder). The common factors influencing the improvement effect of RSD on different soils were analyzed through redundancy analysis and random forest analysis. Results showed that the electrical conductivity, Fusarium oxysporum abundance, proportion of fungi/bacteria and Fusarium oxysporum/fungi in both soils could be effectively reduced by RSD treatments, and pH in both soils were significantly increased after all of RSD treatments. However, these values of above-mentioned soil properties after different RSD treatments showed significant differences. The overall ranges of soil pH, electrical conductivity, and disinfestation effect were 6.48-8.64, 0.15-0.22 mS/cm, and 0.6%-99.9%, respectively. RSD treatments significantly increased soil pH when the temperature was higher than 10℃ for 3 weeks. The best removal effect of RSD on soil salinization was found in the soil flooding condition, and the disinfestation effect of Fusarium oxysporum was more than 99.7% in both RSD-treated soils at 40℃. Correlation analyses further revealed that the temperature was significantly correlated with pH and microbial properties in both soils after RSD treatments. Moreover, the contributions of the factors to the RSD disinfestation effects in both soils were ranked as follows:temperature > time > organic material > water content. In conclusion, our study shows that temperature is the most important factor affecting the RSD effects in different soil types.

S154.3

国家自然科学基金项目（32160748，42090065）、中国博士后科学基金面上项目（2021M691625）和农田生态保育与污染防控安徽省重点实验室开放基金项目（FECPP201901）资助。