Background The important study of highway are plantation vegetation community and soil, but most of these researches were focused on the beginning period. The research method of the relationship between vegetation and soil during the restoration process are singleness.

Methods In this study, 8 typical vegetation communities were chosen in Xinyang-Nanyang highway which belong to Hushan highway. They were Vitex negundo + Amorpha fruticosa vegetation community, Broussonetia papyrifera + A. fruticosa vegetation community, A. fruticosa + Imperata cylindrical vegetation community, A. fruticosa + Festuca elata vegetation community, Amorpha fruticosa+Duchesnea indica vegetation community, A. fruticosa + Heteropappus hispidus + Cynodon dactylon vegetation community, V.negundo + I. cylindrical + C. dactylon vegetation community and F. elata + Vicia sepium vegetation community. Quadrat method was used in the vegetation community investigation, density, coverage, height of every plant were recorded and Shannon-Wiener index, Pilou index and Richness index were calculated in this study. Eleven soil indexes were measured, such as soil bulk density, saturated water capacity, water moisture, total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus, available potassium, organic matter and pH value. Grey relational degree modeling was used to analysis the degree of coupling and interaction between vegetation community diversity and soil properties. 14 factors were involved in the grey relational degree modeling, three of them were species diversity indexes and 12 of them were soil indexes.

Results The result showed that F. elata + Vicia sepium vegetation community had the highest Shannon-Wiener index and Richness index, the V. negundo + I. cylindrical + C. dactylon vegetation community had the highest Pielou index. The nutrient of 0-10 cm layer were higher than 10-20 cm layer, but the water content were lower than 10-20 cm layer. The result of grey relational degree modeling indicated that the vegetation communities in shady slope have good coupling degree than sunny slope. There were two vegetation communities had superior coordination in the 8 different vegetation communities, they were A. fruticosa + F. elata community in shady slope and A. fruticosa + D. indica community in sunny slope. Two of these vegetation communities were favorable coordination, three of them were middle coordination and one of them was light coordination.

Conclusions The water moisture, total potassium, soil bulk density, total nitrogen, pH, total phosphorus, available potassium factor had a great influence to the diversity index of vegetation community, people could carry on the improvement target-oriented to the slope. It is suggested that this plant furnishing could be promoted which contain different life style of Leguminosae and perennial herb that based on the analysis of the vegetation communities which had superior coordination.