根系对橡胶树/海芋间作系统中氮素竞争的响应机制

It is very important to develop the land under the mature rubber plantation,that reaches up to millions of hectares, to intercrop in the land to increase output of rubber plantation, employment opportunities and income for the rubber farmers. However, most of the land is not used due to few promising potential market intercropping patterns are recommended because of the strong competition for the mineral nutrition and light resource between rubber trees and intercrops. Rubber tree / calla lily intercropping is a new promising intercropping pattern in the high shaded mature rubber plantation that can produce the industrial starch, and etc. In this project,the technique of root barriels and 15N tracer will be carried out to study the response of the root growth and development, morphology and structure, distribution, root physiological characteristics of rubber tree and calla lilies and of rhizosphere soil mineral nutrient content, rhizospheric microbial species and quantity, the rhizospheric soil enzyme activity to intercropping as well as the relation between changes in these indexes and nitrogen uptake competition between rubber tree and calla lily in the intercropping pattern, to reveal the mechanisms on the root responses to nitrogen competition in rubber tree / calla lily intercropping pattern, to provide a theoretical basis for further studying the integrated management of the soil nutrients of mature rubber plantation intercropping.

我国有可间作利用的成龄胶园林下土地达数百万亩，开发利用这些资源对于充分利用珍贵热区土地资源，增加产出，增加劳动就业机会和促进胶农增收等有重大意义。但是，由于主间作物在土壤养分、光资源利用等方面的强烈竞争而相互影响导致有市场前景的成龄胶园间作模式不多，致使大量成龄胶园林下土地资源未能利用。橡胶树/海芋是一个新的成龄胶园间作模式，可在较荫蔽的成龄胶园开展工业海芋淀粉原材料等间作生产。本项目拟以橡胶树/海芋间作系统，采用根系分隔实验结合15N稳定性同位素示踪技术，系统研究橡胶树、海芋在间作系统中根系生长发育、形态结构、分布、生理特性，根际土壤矿质养分含量、根际土壤微生物种类、数量、根际土壤酶对间作的响应情况以及这些指标变化与橡胶树、海芋主间作物对氮素竞争吸收利用规律的关系，以进一步揭示成龄胶园主间作物根系对间作系统中氮竞争的响应机制，为进一步探讨胶园间作土壤养分综合管理提供理论依据。

我国有可间作利用的成龄胶园林下土地达数百万亩，开发利用这些资源对于充分利用珍贵热区土地资源，增加产出，增加劳动就业机会和促进胶农增收等有重大意义。但是，由于主间作物间在土壤养分、光资源利用等方面的强烈竞争而相互影响导致有市场前景的成龄胶园间作模式不多，致使大量成龄胶园林下资源未能利用。本项目在成龄胶园中间作了20多种作物，探讨不同作物对胶园土壤的养分影响及间作对作物本身的影响。研究结果表明在成龄胶园中间作，橡胶树和间作物之间存在养分竞争。在成龄胶园内进行间作，必须加强间作物施肥，以实现土壤养分收支平衡，维护土壤功能、保护土壤质量。本项目以橡胶树/海芋间作系统，采用根系分隔实验结合15N稳定性同位素示踪技术，系统研究了橡胶树、海芋在间作系统中根系生长发育、形态结构、分布、生理特性，根际土壤矿质养分含量、根际土壤微生物种类、数量、根际土壤酶对间作的响应情况以及这些指标变化与橡胶树、海芋主间作物对氮素竞争吸收利用规律的关系，揭示了成龄胶园主间作物根系对间作系统中氮竞争的响应机制，为进一步探讨胶园间作土壤养分综合管理提供理论依据。