棉秆炭配施生物有机肥对连作棉花根际土壤化感物质和黄萎病发生的影响

The increasingly serious Verticillium wilt disease caused by Long-term continuous cropping had directly affected to healthy development of XinJiang cotton industry.Recent research showed that soil-borne disease was closely related with soil ecological environment,especially accumulation of allelochemicals in rhizosphere soil and change of microbial community.Cotton stalk and bio-organic fertilizer could adjustment of soil microbial ecology,adsorption and degradation allelochemicals and inhibit pathogen growth in rhizosphere soil.At the same time biochar can promote microbial.So the applicant think that cotton stalk with bio-organic fertilizer will be probably a new method to reduce Verticillium Wilt disease.In this project,continuous cropping cotton will be taken as the object of this study.We will focus on the effects of cotton stalk with bio-organic fertilizer on allelochemicals of continuous cropping cotton rhizosphere soil,microbial diversity and protective enzyme activity in cotton by determining substances and variation of allelochemicals,using soil microbial ecology and statistical methods.At the same time,we will definite to effect of cotton stalk with bio-organic fertilizer on Verticillium wilt disease.The results of these studies will provide theoretical basis and practical value for controlling cotton soil-borne diseases by cotton stalk with bio-organic fertilizer.

长期连作棉田黄萎病日益严重直接影响新疆棉花产业健康发展。研究表明，土传病害发生与连作作物根际土壤化感物质累积、微生物群落变化等密切相关。生物炭和生物有机肥都具有调节土壤微生态，吸附和降解土壤化感物质，减缓病害发生等作用；同时生物炭能促生微生物。由此申请人认为棉秆炭配施生物有机肥可能是一种有效减轻连作棉花黄萎病的新方法。本研究以施用棉杆炭、生物有机肥及二者配施条件下连作棉花为研究对象，通过提取棉花根际土壤化感物质，采用高压液相色谱等测定化感物质成分，分析变化规律；采用传统培养和分子生物学方法分析土壤微生物多样性；同时监测棉花黄萎病病菌变化、测定棉花体内防御性保护酶等；分析阐明棉秆炭配施生物有机肥对连作棉花根际土壤化感物质和微生物多样性及植株防御性保护酶的关系，明确棉秆炭配施生物有机肥对棉花黄萎病发生的影响。研究成果将为防治棉花黄萎病等土传病害提供理论依据。

棉田长期连作和棉秆直接粉碎还田在一定程度上导致棉田连作障碍的发生，目前将生物炭和生物有机肥联用已成为提高单个效果的新方向。本项目采用实验室模拟、盆栽试验及田间应用相结合的方法，对新疆连作棉田棉秆炭配施生物有机肥根际土壤养分和化感物质含量、微生物群落结构和功能多样性、拮抗菌和病原菌数量及棉花长势和抗病性的影响展开了较为系统的研究，在以下方面取得了重要进展：. （1）模拟试验表明，配施棉秆炭能提高连作棉田土壤中生防放线菌数量，增强生防菌制剂的防病促生作用，改善连作棉田土壤微生物群落结构，在防控棉花连作障碍上具有较大的应用潜力。. （2）采用常规方法、Biolog微平板和高通量测序技术，分析了棉秆炭配施生物有机肥对连作棉田根际土壤微生态和棉花生长的影响。盆栽试验证实，棉秆炭配施生物有机肥处理显著提高了根际土壤养分和可培养微生物多样性、降低了Fusarium病原真菌数量。Biolog碳源利用表明，二者配施提高了土壤微生物多样性，各处理间有较明显差异，糖类和氨基酸类是决定分异的主要碳源。同时棉秆炭配施生物有机肥促进了棉花生长，提高了棉花的防御酶活性，能更好防控棉花连作障碍。生物有机肥中增施棉秆炭，由于两者配施土壤微生物多样性的改变以及棉秆炭的吸附作用，降低了土壤中化感物质含量，进而缓解了化感物质对土壤和植株的伤害。. （3）经过2年棉秆炭的施用显著增加了连作棉花根际土壤养分含量和细菌多样性，减少了真菌多样性和黄萎病病原菌数量。虽然没有显著降低棉花黄萎病发病率，但有缓解病害发病程度的趋势。. 综上所述，经过4年的研究表明，棉秆炭具有作为生防菌良好载体的潜力。与常规化肥、单施棉秆炭或生物有机肥相比，棉秆炭配施生物有机肥改善了连作棉花根际土壤微生态环境，促进了棉花生长。因此，综合土壤环境和植株生长两方面因素可以看出，棉秆炭配施生物有机肥缓解棉花连作障碍的效果优于单施棉秆炭或生物有机肥的处理。