设施蔬菜连作障碍原因综合分析与防治措施

  目的  为了探索种养模式下，不同品种蚯蚓对连作土壤微生态及西瓜长势的影响，阐释蚯蚓防控西瓜连作障碍机制。  方法  基于连作6 a的西瓜设施大棚，以连作障碍成因为切入点，设置不投放蚯蚓（CK）、投放0.6 kg m⁻²赤子爱胜蚓（T1）、投放0.6 kg m⁻²威廉环毛蚓（T2）3个处理，监测不同时期土壤微生态、西瓜长势的变化动态，并分析它们之间的相关性。  结果  与CK相比，西瓜移栽前，T1、T2增加了土壤总养分（23.92% ~ 31.90%）、有效养分（10.67% ~ 13.70%）的含量；西瓜种植季，T1、T2显著降低土壤的pH（2.03% ~ 8.25%）、总酚酸（23.98% ~ 60.80%）、容重（3.79% ~ 5.39%）、西瓜枯萎病病原菌的数量（22.93% ~ 59.18%），显著提高了细菌数量、土壤细菌/真菌比值，显著降低了西瓜枯萎病的发病率（10.00%以上），促进了主蔓生长（增加了71.43%以上）。而与T1相比，T2能更好的改善土壤微生态环境，降低连作障碍的发生。  结论  蚯蚓能显著改善土壤微生态，促进西瓜生长，从而缓解连作障碍，而且土壤微生态、西瓜长势均与土壤微生物密切相关。

Plant-soil feedbacks and soil sickness: from mechanisms to application in agriculture

  Objective  Continuous cropping resulted in soil microbial deterioration and serious soil-borne diseases. Earthworms could improve soil quality, however, there are few studies on the effect of earthworms to alleviate continuous cropping obstacles. This study determined how earthworms affected soil microecology and watermelon growth and the underlying mechanisms in the watermelon-earthworm co-culture pattern.   Method  Based on a six-year watermelon continuous cropping system, three treatments were selected: no earthworms (CK), inoculated Eisenia fetida with 0.6 kg m⁻²(T1), inoculated Pheretima guillemi with 0.6 kg m⁻² (T2). The changes of soil microecology nutrients, physicochemical properties, allelochemicals, microorganisms, and watermelon growth in different periods were monitored, and the correlation between them was analyzed.   Result  The results showed that soil total nutrients and available nutrients of T1 and T2 were significantly higher than CK (23.92%-31.90%, 10.67%-13.70%, respectively) at the transplanting period of watermelon seedlings. Compared with CK, T1 and T2 significantly reduced soil pH (2.03%-8.25%), total phenolic acid (23.98%-60.80%), bulk density (3.79%-5.39%), the number of F. oxysporum f. sp. niveum (22.93%-59.18%), and significantly increased the number of bacteria and the ratio of bacteria to fungi. At the same time, T1 and T2 significantly promoted the growth of watermelon (the incidence of Fusarium wilt was reduced by more than 10.00%, and the length of the main vine was increased by more than 71.43%) compared with CK. Compared with T1, T2 was more effective in alleviating continuous cropping obstacles. Correlation analysis showed that soil microorganisms were the primary factor for earthworms to alleviate watermelon continuous cropping obstacles.   Conclusion  Earthworms significantly improve soil microecology and promote the growth of watermelon, which will alleviate continuous cropping obstacles. Moreover, soil microecology and watermelon growth are closely related to soil microorganisms.