Impacts of dung pats on nitrogen in root-layer soils of Zoysia japonica pasture

Nitrogen variations in root-layer soils of Zoysia japonica pasture were studied. The results showed that the variations of soil total N and C/N ratio were related to the general fertility levels in the pasture soils, and were also affected by the intensity and history of grazing on the pastures. However, inorganic N, including nitrate N and ammonium N, was affected a little by these factors. The form of ammonium N dominated over the inorganic N in the root-layer soils. In the pasture soils, the dung pats defecated in the previous year weakly influenced the soil nitrogen levels in the root-layers of the next growing season. Therefore, the duration of the spatial heterogeneity of soil nitrogen in root-layers induced by cattle dung usually might not exceed two growing seasons. Tab 1, Ref 10.