采用人工控制土壤贮水量，在陕西关中气候条件下，研究作物土壤水分生产能力结果表明：土壤水分生产能力小麦最高为１７．５９ｋｇ／（ｈm₂·ｍｍ），谷子１１．６１ｋｇ／（ｈm₂·ｍｍ），豌豆１０．３３ｋｇ／（ｈm₂·ｍｍ），油菜１０．６ｋｇ／（ｈm₂·ｍｍ）；获得一定籽粒产量的最低土壤水分临界值约为：小麦１６０ｍｍ，豌豆１５０ｍｍ，谷子和油菜３００ｍｍ，土壤水分超过此临界值后，增加水分，作物产量大幅度提高，但当水分超过一定量（豌豆３００ｍｍ，小麦４００ｍｍ，谷子５００ｍｍ，油菜６５０ｍｍ时），产量则渐趋于稳定；低供水多施肥和高供水少施肥土壤水分的无谓消耗增加，不利于提高土壤水分的生产能力，必须量水施肥，才能提高土壤水分生产能力。

The crop productive ability of soil moisture is studied by using the artificial moisture control under the climate in Shanxi Guanzhong.The results show that the highest soil moisture productive ability for wheat is 17.59kg/hm₂.mm),for millet 11.61kg/(hm₂.mm),for pea 10.33kg/(hm₂.mm),and for rape 10.46kg/(hm₂.mm).The critical value of soil moisture storage to obtain a certain output of wheat is about 160mm,of pea 150mm of millet and of rape 300mm.After the storage of soil moisture is over the critical value crop yield can be greatly improved with an increase of storage of soil moisture.But when soil moisture exeeeds a certain amount,crop yield tends to be stable.For example,for pea when soil moisture exceeds 300mm,for wheat 400mm,for millet 500mm,and for rape 650mm.Soil moisture productive ability can not raised when moisture is insufficient and fertilizer is abundant or when moisture is abundant and fertilizer is insufficient.At this time,the soil moisture ineffectively consumed.The soil moisture productive ability can be improved by applying fertilizer according to moisture conditions.