客土改良对植烟土壤营养及烟草青枯病的影响

摘要

The sandy soil suffers serious tobacco bacterial wilt in Nanxiong tobacco growing areas, Field trials were conducted by blending natural weathered red sand (purple soil) at different ratios in the tillage layer of the sandy soil. The changes of soil nutrient and control effects to bacterial wilt after mixture were analyzed. The results showed that after blending red sand in the tillage layer of sandy soil (which was prone to tobacco bacterial wilt) at 150-450 m3/hm2, the pH value changed from acidic (4.78) to neutral (7.06), and the exchangeable calcium content increased by 3 to 4 times. The population of bacteria and fungi declined, while the actinomycetes increased. The bacterial wilt incidence and morbidity index decreased by 42.2%-73.5% and 51.4%-81.1% respectively compared with the control (sandy soil). The correlation analysis demonstrated that pH value and actinomycetes population showed a significant negative correlation with bacterial wilt incidence and disease index. In summary, mixing certain percentage of red sand in the tillage layer of the tobacco planting sandy soil (in which bacterial wilt was severe) could prevent or reduce tobacco bacterial wilt.%针对南雄烟区沙泥田烟草青枯病发病重的问题,采用大田试验方法,于植烟沙泥田耕层土壤中掺混了一定比例自然风化的红砂土(紫色土),研究了掺混后的土壤营养状况变化规律,并分析了沙泥田掺混红砂土对烟草青枯病的防治效果及原因.结果表明,在易发烟草青枯病的沙泥田耕层土壤中掺混红砂土150~450 m3/hm2后,土壤pH由酸性(4.78)渐变为中性(7.06),交换性钙离子含量增加了3~4倍,土壤中青枯病菌、细菌和真菌数量减少,而放线菌数量增加,青枯病发病率和病情指数比沙泥田分别下降了42.2%~73.5%和51.4%~81.1%.相关分析表明,pH、放线菌数量与青枯病发病率、病情指数均呈极显著负相关.在青枯病发病率高的植烟沙泥田耕层土壤中,掺混一定比例的红砂土可防治或减少烟草青枯病的发生.