新疆棉花种植面积与产量居全国第一，因环境条件特殊，形成了棉花长期连作并实施棉秆还田的独特生产技术体系，导致连作障碍现象日益严重。研究证实，秸秆还田的自毒化感效应是导致作物连作障碍的重要原因之一。项目组前期研究以筛选到的复合菌剂人工腐解棉秆，发现可有效消除棉秆腐解物对棉花的自毒作用，降低潜在化感物质含量，并对棉花枯黄萎病菌具有较好抑菌效果。基于此，本研究拟进一步验证和拓展棉秆促腐还田的适用性，在已有菌种基础上，通过盆栽实验确定腐解菌种类、剂型及施入方式，然后开展田间试验分析施入腐解菌剂后对棉花生长的化感效应及枯黄萎病发病情况；比较根际土壤中潜在化感物质的差异及含量变化，并对其中主要差异成分进行化感作用生物测定；监测根际土壤理化性状、土壤酶活及根际微生物群落动态变化，以期揭示出连作棉田棉秆促腐还田化感作用规律及棉花根际微生态的响应机制，从而为最终建立合理的棉秆还田方式奠定有益的理论基础。

Xinjiang province is the largest cotton planting area in China, the cultivation area and yield of cotton rank first in the nationwide. Long-term continuous cropping and unique production technology of returning cotton stalk to field have formed due to special geographical environment,which have led to increasingly serious continuous cropping obstacles. It has been proved that the autotoxicity resulting from straw returning to field is one of the most important reason for continuous cropping obstacles. Our group has decayed cotton stalk by using the complex of lignocellulose decomposing strains previously isolated, found that the microbial decaying way could effectively eliminate the autotoxicity of cotton stalk decomposed residues to cotton growth, reduce potential content of allelochemicals, and effectively inhibit colonization of Fusarium and Verticillium wilts. Therefore, this research plans to furtherly validate and expand the applicability of promoted-decaying cotton stalk returning to field. The type of decaying microbial inoculum, strain preparing form and application way will be determined through pot experiments on the basis of existing strains, the allelopathy on cotton growth and the infectious status of Fusarium and Verticillium wilts will be analyzed after applying decaying microbial inoculums in field experiments,the differences of allelochemicals in rhizospere soils will be examined, the bioassay will be developed to examine allelopathy of main different chemicals; and the physiochemical properties of rhizospere soils, soil enzyme activity and dynamic variation of rhizosphere microflora will be measured, with expectation to reveal the dynamic variation of allelopathy of promoted-decaying cotton stalk returning to continuous cropping cotton field and response mechanism of cotton rhizosphere microecology, and provide helpful theoretical basis for reasonable way of cotton stalk returning to field.