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对宁南山区旱地紫花苜蓿土壤水分及产量动态进行了研究。结果表明，随苜蓿草龄的延长，土壤深层水分亏缺严重；草地底层与中层对表层水分具有明显的补偿作用；伏秋降水对冬前土壤蓄水亦有重要作用；产量随草龄延长呈中间高两头低的态势，６～８年以后草地须及时更新。
The dynamics of soil water and yield of alfalfa in dry land of south Ningxia were studied. The results showed that with the increase of the age of alfalfa, the water deficit in deep soil was serious. The groundwater layer and middle layer of meadow grass had a significant compensatory effect on the surface water. The autumn precipitation of volumn also played an important role in soil water storage before winter. The middle of two high low, 6 to 8 years after the grass must be updated in time.