Effects of over-seeding on plant community and soil physical and chemical properties of degraded grassland in Tianzhu County

In order to understand the effects of over-seeding on vegetation composition, soil physical and chemical properties, a field experiment was conducted to determine the effect of over-seeding Elymusnutans, Bromusinermis, Festuca sinensis seeds on degraded grassland during the period of 2007 to 2009 in Tianzhu county. The results of this study showed that over-seeding increased the aboveground and belowground biomass and increased the percentage of sedge and gramineain plant community composition. After three years of over-seeding, the soil physical, chemical properties and microbial biomass contenthadbeen obviously improved when compared to control, indicating that soil bulk density at 0―20 cm became low, and that porosity, moisture content, nutrient content and microbial biomass content C & N became higher. These implied that the degraded grassland had been improved by over-seeding.