中文摘要：

利用内蒙古典型草原区3个站点近15年的天然牧草地上生物量、土壤水分和气象观测资料，对降水量、土壤水分和耗水量与不同时期牧草产量的关系进行了统计分析，建立了相应的经验方程，结果表明：各水分因子与产量的相关性依次为土壤水分〉耗水量〉降水量；在时间尺度上，水分对产量的影响存在前期小中后期大的趋势。表现为随生长进程的推进，相关程度逐渐增强．同时水分对产量的影响存在累加效应；一般情况下，典型草原牧草产量所需的水分基本由0～50cm土层提供；土壤水分和耗水量与产草量的关系用直线或指数方程拟合效果较好，降水与产草量的关系多用二次曲线拟合。这些结论和方程对牧草产量监测币口旱情评价、分析有一定的参考价值。

英文摘要：

The paper analyzed the relations of precipitation, soil moisture, water consumption and forage yield at different time, and established the corresponding empirical equation by using biomass, soil moisture of natural grasslands and meteorological data of nearly 15 years in 3 stations of Inner Mongolian typical steppe area. The result indicated that correlation of various moisture factor with the yield was soil moisture 〉 water consumption 〉 precipitation; Influence of moisture on the yield had the tendency of small in earlier growth period and larger in middle and later period, indicating that the relativity increased with the growth of forage, moisture content had accumulative effect on forage yield. In ordinary circumstances, the moisture content of forage yield has been basically provided by 0-50 cm soil layers. The relations of soil moisture, water consumption and forage yield could be modeled by linear or exponential equation; The relationship between precipitation and forage yield be modeled by second-degree curve. The conclusions and equations could provide reference to forage yield monitoring, drought evaluation and analyzing.