深翻和施用土壤改良剂对烟草青枯病发生的影响

摘要

为探讨土壤管理措施对烟草青枯病发生的影响及其机制，通过田间试验研究了土壤翻耕深度、土壤改良剂类型和施用方式对烟草青枯病发病率和病情指数的影响及其与土壤性质变化的关系。结果表明，土壤深翻不能有效抑制烟草青枯病害的发生，且随翻耕深度的增加，烟草青枯病发病反而呈现加重的趋势；土壤翻耕配合改良剂的施用对烟草青枯病害的发生有重要影响：配施石灰无抑制作用，而配施生物质炭或堆肥，以及石灰、生物质炭和堆肥两两配合均能降低青枯病害的发病率，其中以配施生物质炭的效果最明显；翻耕结合施用改良剂对青枯病发生的作用效果与对土壤性质的影响有关，烟草青枯病的发病率与土壤有机质、碱解氮、有效铁、有效锰和交换性镁含量（质量分数）显著负相关，而与土壤pH正相关。因此，烟区土壤翻耕深度不宜过深，且在翻耕过程中应增施有机肥及中微量元素，配合施用生物质炭、堆肥等改良剂，这些措施有助于缓解根茎病害易发区内烟草青枯病害的发生。%In order to study the effects of soil management measures on the incidence of tobacco bacterial wilt disease (TBWD), the effects of ploughing depth, soil amendment type and application mean on the incidence and disease index of TBWD and their relationships with soil physiochemical properties were studied via field experiments. The results showed that deep-ploughing did not effectively inhibit the occurrence of TBWD, and the incidence and disease index of TBWD tended to increase with the increase of ploughing depth. Amendment application accompanying ploughing affected the incidence of TBWD significantly: other than applying lime only, applying biochar or compost or lime, biochar and compost in pairs could decrease the incidence of TBWD, especially applying biochar. The influences of amendment application accompanying ploughing on TBWD incidence related to its effects on soil properties. Correlation analysis showed that the incidence of TBWD significantly negatively correlated to the contents of organic matter, alkaline hydrolytic N, available Fe, available Mn and exchangeable Mg in soil, while positively correlated to soil pH. It is recommended that for the purpose of reducing the incidence of TBWD, the depth of ploughing should be controlled within 40 cm, however, adding organic fertilizer, middle and trace elements along with biochar and compost application would be helpful.