在宁夏盐池天然草地生长季内采用补充浇水方法,求取牧草需水系数K_d.并引用范·费尔图依森提出的作物田间需水量E_(ml).采用公式:E_(ml)=∑K_(cl)·E_(ol)(E_(ol)为第i生育阶段可能蒸散量),计算、分析天然草地主要生育阶段以及整个生长季需水量及其变异规律,并建立降水量-产量模式.以水分满足率(实际蒸散量与需水量之比值)为指标,分析天然草地水分供应状况及其对潜在产量影响. In the growing season of natural grassland in Yanchi, Ningxia, the watering coefficient K_d of forages was determined by adding watering method, and the field water requirement E_ (ml) was put forward by Van Feritur. The formula: E_ (ml) = ΣK_ (cl) · E ol (E_ (ol) is the possible evapotranspiration in the i-th growth stage), calculating and analyzing the water requirement and its variation pattern in the main growth stages of the natural grassland and the whole growing season, and establishing the precipitation-yield Model.With the water satisfaction rate (the ratio of actual evapotranspiration to water demand) as an indicator, the status of natural grassland water supply and its impact on potential yield were analyzed.