Because of the over-grazing and unreasonable reclamation, the ecological condition of the grassland in Inner Mongolia is worsening, for example, the grass gradually sparsing, desert spreading etc, and agricultural development has been seriously affected. In order to maintaining the ecological balance, protecting the environment and alleviating the pressure of grazing, forage grass is planted that becomes one of important content in agricultural structure adjusting and constructing. Water requirement of fora...