提高磷素生物有效性是当前绿洲农业可持续发展亟待解决的问题之一。根际是作物-土壤-微生物及环境相互作用最剧烈的区域，但土壤磷素生物有效性的根际调控机制尚不明确。课题组前期结果表明：间作模式磷素有效性高于单作和轮作。随着农业供给侧结构性改革，棉花种植面积调减，研究不同棉田间作模式磷素生物有效性机制，对于提高磷素利用率具有重要意义。本项目拟在前期工作的基础上，通过长期定位试验结合现代分子生态学研究手段，研究棉花为主间作模式对根际土壤磷素生物有效性和磷素吸收利用的影响，分析根际分泌物对作物磷素吸收利用的综合效应，进一步揭示作物根系-根际微生物对话过程中影响磷素生物有效性和转化关键基因的调控机制，以期建立土壤磷素高效利用的适应性种植模式，为恢复和建立绿洲棉田合理用养制度提供技术支持。

Improving the soil phosphorus (P) bioavailability of is one of the urgent problems to be solved for the sustainable development of oasis agriculture. The rhizosphere of plants is a place with the most intense plants-soil-microbe and their environment interactions, but the rhizosphere mechanism for regulating soil P bioavailability remains poorly understood. Our previous studies indicated that the P bioavailability of intercropping is higher than that of monocropping and rotation. With the structural reform of agricultural supply side deepening and the reduction of cotton planting area, therefore, the study on soil P bioavailability mechanism of different cotton based intercropping systems is of great importance for improving the utilization of soil P. Based on the preliminary work, the objectives of this project are to, (i) investigate the effects of different cotton intercropping systems on the rhizosphere soil P bioavailability and the absorption and utilization of phosphorus using long-term experiments combined with modern molecular ecology research methods, (ii) analyse the comprehensive effect of rhizosphere secretions on the absorption and utilization of phosphorus in crops, (iii) reveal the regulation mechanism of key genes affecting P bioavailability and transformation during the crop root-rhizosphere microbial dialogue. This research may provide the theoretical support for establishment of a rational use and maintenance for oasis cotton fields.