摘要：
[Objectives] Effects of a alkaline fertilizer on soil microbial activity and microbial diversity were studied,and mechanism of the alkaline fertilizer on reducing the incidence of FOC in banana plantation was revealed.[Methods] A pot experiment with the split plot design was conducted.The main plot was compound fertilizers whose pH values were 5.5,7.0 and 8.0,and the subplot was inoculation with Fusarium oxysporum f.sp.cubensce (E.F.Smith) Snyder et Hasen (FOC) at × 106 cfu/g and without inoculation.The diversity of soil microbial communities and occurrence of banana wilt disease were investigated.[Results] 1) The incidence of FOC in banana treated with the alkaline and neutral fertilizer treatments significantly decreased the wilt infection and disease index,which were decreased by 38 and 16 percentage points in the alkaline fertilizer treatment compared to those treated with the acid fertilizer.2) The banana biomass in the alkaline fertilizer treatment was significantly higher than those in the neutral and acid fertilizer treatments under the condition of FOC inoculation,the increments were by 15％ and 23％,respectively.3) The amount of FOC and fungi population in the soils treated with the alkaline fertilizer were remarkably lower,the decrements in FOC and fungi population were by 60％ and 51％ respectively,while the amount of actinomycetes and bacteria population were significantly higher than those in the acid fertilizer treatment,being 1.22 and 2.25 times of those in the acid fertilizer treatment,respectively.4) Compared to the acid fertilizer treatment,the average well color development (AWCD) in the alkaline fertilizer treatment was significantly higher,and the Richness and Shannon-Weaver diversity index were also notably higher.[Conclusions] The application of alkaline fertilizer could obviously increase population of actinomycetes and bacteria,the soil microbial community structure become healthy as the soil microbial activity and diversity are increased,and the growth and infection of FOC and fungi are significantly prevented during banana growth.%[目的]研究碱性肥料对土壤微生物活性及多样性的影响,探究防控香蕉枯萎病的有效途径.[方法]采用两因素裂区设计进行了盆栽试验.主处理是施肥量相等、pH值分别为5.5、7.0、8.0的3个氮磷钾复合肥(22-8-15);副处理为接种香蕉枯萎病尖孢镰刀菌[Fusarium oxysporum f.sp.cubensce (E.F.Smith) Snyder etHasen],包括不接种尖孢镰刀菌(FOC)、接种FOC× 106 cfu/g两个水平,共6个处理.[结果]1)施用pH为7和8的两种肥料处理显著降低了香蕉枯萎病的染病率及病情指数,pH 8.0的碱性肥料较pH 5.5的酸性肥料分别降低了38和16个百分点.2)接种FOC后,碱性肥料相比中性和酸性肥料显著增加了香蕉整株生物量,增加量分别为15％和23％,而对香蕉根部生物量影响不显著.3)肥料的酸碱性对土壤微生物群落数量有显著影响,碱性肥料处理土壤中的FOC和真菌数量显著少于酸性肥料处理的,分别减少了60％和51％,而放线菌和细菌数量却都明显多于酸性肥料处理的,分别是酸性肥料的1.22和2.25倍.4)碱性肥料较酸性肥料提高了土壤微生物的总碳源利用率及活性;在接种FOC的情况下,碱性肥料较酸性肥料可以显著地提高土壤微生物多样性.[结论]施用碱性肥料能明显减少土壤中FOC和真菌数量,增加细菌、放线菌数量,显著优化土壤微生物种群结构,提高土壤微生物活性及多样性,有效抑制FOC的萌发和致病,从而有效防控香蕉枯萎病的发生.
