棉秆炭配施生物有机肥对连作棉花根际土壤微生态和棉花生长的影响

为了研究棉秆炭配施生物有机肥对棉花连作障碍的防控效果,采用盆栽试验,以连作棉田土壤为试验材料,设计连作土壤(CK)、连作土壤+棉秆炭(T1)、连作土壤+生物有机肥(T2)、连作土壤+棉秆炭+生物有机肥(T3)共4个处理。采用常规方法、Biolog微平板和高通量测序技术,分析不同处理对连作棉花根际土壤养分、微生物数量、功能多样性和病原真菌数量、棉花长势和与抗病性相关的叶片防御性保护酶活性的影响。结果表明:棉秆炭、生物有机肥以及二者配施可显著提高连作棉花根际土壤养分含量和可培养微生物数量,以二者配施(T3处理)的提升效果最好。与CK处理相比,T3处理土壤有机质、速效磷和速效钾含量分别显著提高46.09%、19.71%和144.75%;细菌、放线菌和真菌数量分别显著提高62.32%、63.46%和11.74%。Biolog微生物碳源利用试验表明,T3处理并没有显著增加Biolog微平板上碳源的利用,但提高了土壤微生物多样性,且不同处理间有较明显差异,糖类和氨基酸类是决定主成分分异的主要碳源。高通量测序结果表明,T3处理显著降低了Fusarium病原真菌的数量。棉秆炭、生物有机肥以及二者配施对棉花生长均起促进作用,以T3处理的效果最好,棉花的株高、茎粗、根长分别比CK处理显著增加18.24%、13.89%和14.53%,叶片多酚氧化酶(polyphenol oxidase,PPO)和苯丙氨酸解氨酶(phenylalanine ammonialyase,PAL)活性分别显著提高116.28%和182.55%。综上,与对照、单施棉秆炭或生物有机肥相比,棉秆炭与生物有机肥配合施用改善了连作棉花根际土壤微生态环境,促进棉花生长,同时提高棉花的防御酶活性,能更好防控棉花连作障碍。结果为棉秆科学高效利用和棉花产业健康可持续发展提供理论依据。

Effects of Cotton Stalk Biochar Combined with Bio-organic Fertilizer on Rhizosphere Soil Micro-ecology and Cotton Growth of Continuous Cropping Cotton

In order to research the prevention and control effects of cotton stalk biochar combined with bio-organic fertilizer on obstacles of continuous cropping cotton, the typical continuous cropping cotton soil was selected for pot experiment, and four treatments, including no cotton stalk biochar and bio-organic fertilizer additions (CK), cotton stalk biochar addition (T1), bio-organic fertilizer addition (T2), cotton stalk biochar and bio-organic fertilizer additions (T3), were carried out. The effects of different treatments on rhizosphere soil nutrient, microbial quantities, microbial functional diversity and quantity of pathogenic fungi, cotton growth and protective enzymes activities were analyzed by conventional methods, Biolog Eco-microplates and high-throughput sequencing. The results showed that cotton stalk biochar, bio-organic fertilizer and their combined application could significantly increase nutrient contents and culturable microbial quantities in rhizosphere soil of continuous cropping cotton. Cotton stalk biochar combined with bio-organic fertilizer treatment (T3) was the best treatment. Compared to CK, the contents of organic matter, available phosphorus and available potassium in T3 treatment significantly increased by 46.09%, 19.71% and 144.75%, respectively. The quantities of bacteria, actinomycetes and fungi in T3 treatment significantly increased by 62.32%、63.46% and 11.74%, respectively. Biolog carbon resources utilization analysis showed that T3 treatment did not significantly increase the utilization of carbon sources. However it increased soil microbial functional diversity, and there were obvious differences among different treatments. Carbohydrate and amino acids were the main carbon sources that determined the differentiation of principal components. The result of high throughput sequencing showed that T3 treatment significantly reduced the quantity of pathogenic fungi Fusarium. Cotton stalk biochar, bio-organic fertilizer and their combined application could significantly promote cotton growth, and the effect of T3 treatment was the best. Compared to CK treatment, the plant height, stem diameter and root length increased significantly by 18.24%、13.89% and 14.53%, polyphenol oxidase (PPO) and phenylalanine ammonialyase (PAL) activities of cotton leaves significantly increased by 116.28% and 182.55%. Compared with conventional fertilization, the combination of cotton stalk biochar and bio-organic fertilizer was considered to be able to improve rhizosphere soil micro-ecology environment of continuous cropping cotton fields, and promote cotton growth and protective enzyme activities. The present research would provide theoretical basis for scientific, efficient utilization of cotton stalk and healthy, sustainable development of cotton industry.