Preliminary Investigations And Studies On Legumes In Highway Slopes In South China

In recent years, China has made great progress in highway construction. However, highway construction is always accompanied with lots of bare and steep slopes that are exposed to the direct action of rainfall and cause high rates of water erosion and potential safety hazard. Thus the revegetation of highway slopes become an important and pressing project. In the same time,the investigation and selection of plants that used in the slopes are also become more and more important.The legumes not only have values as food and forage crops, but they are also valuable for ecosystem restoration. Nitrogen fixation of legume-rhizobia symbiosis is the most important biological N-fixing system. So the symbioses are put in a very important position in the revegetation of the highway slopes. In this study, legume populations and soil properties in plant communities of highway slopes in the South China were investigated. The results showed that legumes were the most frequently appeared shrubs species on the slopes, but the frequencies of the legumes were much smaller than the companion herbaceous species. The soil properties of the slopes on which legumes were grown were at a low or very low level except organic matter. Only two legume species were formed root nodule on their roots. Accordingly, there were many problems that have to be solve for successful use of the legume- rhizobia symbiosis in the revegetation of the highway slopes, and screening and development of stains of rhizobia being adoptive to the slope conditions should especially be focused.The soil bacterium occupancied 70 ~ 90% of the soil microorganism.It is the largest life activity surface also the most active life factor .Therefore, bacterium counting of soils in the 33 slopes has been carried out , resulting in finding out bacterium quantity and the microorganism general situation of the slopes .The correlation analyzing was done one-to-one between bacterium quantity and four soil characters (pH value , organic matter , Total Phosphorus and Available Phosphorus.The result is that bacterium quantity is related to available phosphorus only. The Anova result of bacterium quantity and respective four soil characters of slopes that has nodule or not is organic matter has the markable deffrence.The study js benefical to promoting the development of ecological restoration of highway slopes.It provides the academic sense of development of new applied system of leguminous plants and rhizobia.A broad applied foreground is also presented in the damaged habitats of restoration.