Impact of planting grass on terrene roads to avoid soil erosion

Abstract

Roads are a wide spread and increasing feature of most landscapes, have great ecological impacts, alter landscape spatial patterns and interrupt horizontal ecological flows strongly. Soil erosion is the dominating factor of damaging terrene roads in rural areas worldwide. Field tests for anti-erosion and maintenance techniques on terrene roads were conducted between 1996 and 2001 in Xiabiangou, Yan’an City in the Loess Hilly-Gully region of Shaanxi Province, China. The results of field tests showed that soil erosion on unpaved terrene roads with no vegetation was 3.09 times that of roads designed using special pavers sown with grass in the same situation. Roads sown with Bromus inermis, Elymus sibiricus, Elymus, Poa annua could bear traffic loads up to 300 vehicles year −1. There were additional yields in benefits from fresh vegetable and seed production by B. inermis with strip sowing amounted to US$ 264.16 km −1 year −1, while that for Coronilla varia and Lespedeza dahurica was between US$ 138.36 and US$ 205.52 km −1 year −1, respectively. In order to avoid nutrient loss in the grass growth on the roads it is necessary to apply fertilizers to compensate for the decline in soil nutrients. The cost of grass road construction was 71.65% less than that of stone roads, with maintenance costs averaging 60.97% less than that of non-grass terrene roads. The results suggest that grass roads can fill the gap between paved and unpaved roads in areas with sloping terrain and low traffic volumes (rural countryside, nature reserves and parks) and thus minimize the level of soil erosion, landscape damage and other environment problems.