沼液处理对土壤微生物性状及西瓜枯萎病发生的影响

采用室内盆栽模拟的方法,研究了沼液保湿和淹水处理对马肝土和潮土微生物性状的影响以及对西瓜枯萎病的防效。结果表明,沼液处理土壤21 d对西瓜枯萎病的防效和病原菌的消减效果较好。两种土壤中,铵强化沼液淹水处理西瓜枯萎病发病率均最低。沼液保湿处理发病率平均比对照降低15%。马肝土中,铵强化沼液淹水处理尖孢镰刀菌数量最少;潮土中秸秆沼液淹水处理对病原菌数量的消减效果最好。沼液处理提高了土壤可溶性有机碳、氮含量以及荧光素二乙酸酯酶活性,其中沼液淹水处理提高幅度更大。对各处理Biolog-ECO板孔平均颜色变化的主成分分析表明,沼液淹水处理、沼液保湿处理的微生物群落结构与水保湿对照处理有明显差异。沼液淹水和铵强化沼液淹水处理能提高土壤微生物功能多样性指数,秸秆沼液淹水处理则显著降低土壤微生物功能多样性指数。

Suppression of fusarium wilt of watermelon by biogas slurry application and its effect on soil microbiological characteristics

Pot experiment was carried out to study the effect of biogas slurry application on microbiological properties of a paddy soil and an alluvial soil. The result showed that the 21-day treatment by biogas slurry significantly reduced the number of the pathogen and disease incidence of fusarium wilt. In the two soils, the disease incidence of fusarium wilt was the lowest in soils flooded by ammonium-intensified biogas slurry. The disease incidence of moist treatment by biogas slurry ( BS) was 15% low-er than that of the control. Ammonium-intensified biogas slurry flooding treatment ( ABSF) and wheat straw plus biogas slurry treatment ( SBSF) had the least number of the pathogen in the paddy soil and the alluvial soil, respectively. Biogas slurry treatments ( BS, BSF, ABSF, SBSF) had higher contents of water soluble carbon, water soluble nitrogen and fluorescein di-acetate hydrolysis activity, and the increase was more significantly for the flooding treatments ( BSF, ABSF, SBSF) than the moist treatment ( BS) . Principal component analysis on the value of average well color development indicated that the microbial community structure among biogas flooding treatment, biogas slurry moist treatment and the control were significantly different. The microbial community functional diversity ( Shannon index) was increased in soils treated by biogas slurry flooding and am-monium-intensified biogas slurry, while the biodiversity index was decreased in wheat straw plus biogas slurry flooding treat-ment.