有机肥配施减量化肥对烤烟青枯病及其根际微生物的影响

Effects of organic fertilizers combined with reduced chemical fertilizers on tobacco bacterial wilt disease and rhizosphere microorganism

为改善烟株根际土壤微生物群落结构,减轻由土壤病原菌引起的青枯病危害,通过田间试验,研究了有机肥配施减量化肥(ORF)和常规化肥(CKF)两种施肥处理对烤烟根际土壤微生物、青枯病发病率及烟叶产量和品质的影响。结果表明:与常规化肥(CKF)相比,有机肥配施减量化肥处理提高了烤烟根际细菌、放线菌和微生物总量,降低了真菌、青枯菌以及青枯菌占根际微生物总量的百分比,移栽后55 d和75 d时差异达到显著水平;此外,也显著提高了微生物对碳源总量和不同类型碳源的利用能力,尤其以移栽后75 d的差异最显著。同时,整个烟草生育期ORF处理均降低了烤烟青枯病发病率和病情指数,以移栽后75 d差异最显著,分别降低69.66%和57.08%。两种处理在烤烟产量和品质上虽无显著差异,但ORF处理明显改善了烤烟根际土壤环境。因此,有机肥配施减量化肥能调控土壤微生物群落结构,增强土壤微生物生态系统的稳定性和抑病性,从而改善土壤品质,减轻由土壤微生物引发的烤烟青枯病病害,提高烟叶品质。

To improve the community structure of rhizosphere microorganism in tobacco-planting soils and alleviate bacterial wilt disease caused by soil pathogens, a field experiment was conducted to study the effects of organic fertilizers combined with reduced chemical fertilizers （ORF） and conventional chemical fertilizers （CKF） on tobacco rhizosphere microorganism, bacterial wilt disease incidence, and the yield and quality of tobacco leaves. The results showed that comparing with CKF, the treatment of ORF increased the numbers of bacterial, actinomyces and total microorganism in rhizosphere soils. However, the number of fungal, Ralstonia solanacearum and the percentage of R. solanacearum in the total amount of rhizosphere microorganism decreased, and the differences were statistically significant on the 55th and 75th days after transplanting. In addition, the average well color development （AWCD） and the utilization ability of various carbon sources increased, especially on the 75th day after transplanting. Simultaneously, the ORF treatment reduced the incidence and index of bacterial wilt disease at entire growth stages, and the differences were statistically significant on the 75th day after transplanting, reduced by 69.66% and 57.08% respectively. There were no significant difference in the yield and quality between the two treatments, but the rhizosphere soil environment of flue-cured tobacco had been significantly improved by the ORF treatment. Therefore, ORF improves the community structure of rhizosphere microorganism, and enhances the stability and disease suppression of soil microbial ecosystem. Furthermore, ORF promotes the qualities of soils and tobacco leaves and alleviates tobacco bacterial wilt disease damage caused by soil microorganism.