Soil degradation in greenhouse vegetable production systems due to salinisation and soil-borne diseases can be mitigated by chemical soil disinfestation (CSD). However, the comprehensive effects of CSD on soil salinisation and the presence of potential pathogens are not well realised. Therefore, the efficacy of CSD in controlling salinisation and soil-borne diseases was studied in a 3-year field experiment with tomato and melon/pepper in rotation. Treatments comprising (i) nil N (CK); (ii) conventional irrigation and fertiliser (CN); (iii) reduced synthetic N fertilisation (RN); (iv) RN with 3,4-dimethypyrazole phosphate (DMPP) (RN + DMPP); (v) a combination of manure and synthetic fertiliser (MN) and (vi) MN with straw (MNS) were applied to soils, and electrical conductivity (EC), nitrate leaching and potential pathogens were measured. Soil EC significantly decreased in 0–20 cm depth but increased in 40–200 cm depth after CSD. CSD treatment significantly accelerated nitrate leaching from 0–100 cm to 100–200 cm soil depth. Nitrate leaching from CN treatment was higher than other treatments. CSD significantly changed microbial diversity, increased network complexity and significantly decreased potential pathogens. The partial least squares path model showed that potential pathogens were positively correlated with α diversity and negatively correlated with community structure and network complexity. The relative abundance of Firmicutes, and significantly increased after CSD treatment, whereas decreases in the relative abundance of Actinobacteria and Proteobacteria members were observed, which is associated with potential pathogen suppression. In conclusion, CSD mitigates topsoil salinisation by promoting nitrate leaching and simultaneously significantly decreasing potential pathogens by altering microbial diversity and composition and increasing network complexity.

中文翻译：

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化学土壤消毒可减少土壤盐碱化和潜在病原体的存在，但代价是增加硝酸盐浸出

化学土壤消毒（CSD）可以减轻因盐碱化和土传疾病造成的温室蔬菜生产系统的土壤退化。然而，CSD 对土壤盐碱化和潜在病原体存在的综合影响尚未得到充分认识。因此，通过为期3年的番茄和瓜/辣椒轮作田间试验，研究了CSD在控制盐碱化和土传病害方面的功效。处理包括 (i) 无 N (CK)；(ii) 常规灌溉和施肥（CN）；(iii) 减少合成氮肥（RN）；(iv) RN 与 3,4-二甲基吡唑磷酸盐 (DMPP) (RN + DMPP)；将（v）粪肥和合成肥料（MN）的组合以及（vi）MN与秸秆（MNS）的组合施用于土壤，并测量电导率（EC）、硝酸盐浸出和潜在病原体。CSD后土壤EC在0-20 cm深度显着下降，但在40-200 cm深度增加。CSD处理显着加速了土壤深度从0-100厘米到100-200厘米的硝酸盐淋溶。CN 处理的硝酸盐淋失高于其他处理。CSD 显着改变了微生物多样性，增加了网络复杂性并显着减少了潜在病原体。偏最小二乘路径模型显示，潜在病原体与α多样性呈正相关，与群落结构和网络复杂性呈负相关。CSD 处理后，厚壁菌门的相对丰度显着增加，而放线菌门和变形菌门成员的相对丰度下降，这与潜在的病原体抑制有关。总之，CSD 通过促进硝酸盐淋溶来减轻表土盐碱化，同时通过改变微生物多样性和组成以及增加网络复杂性来显着减少潜在病原体。