南部大平原畜牧业生产的突出问题之一就是冬季缺少足够的可利用牧草,南部大平原经常出现的干冷气候,对种子发芽和幼苗生长的影响比起对其它生长期的影响还要大些。因此,在大范围的温度和水分条件下种子若能正常发芽,对早期幼苗生长和草地全苗是十分重要的。豆科牧草的发芽速度和发芽率均受温度的影响。地三叶(Trifolium subterraneum One of the outstanding problems of livestock production in the southern Great Plains is the lack of available grass in winter. The dry and cold climate often occurs in the southern Great Plains, affecting seed germination and seedling growth more than other growth periods. Therefore, if the seeds germinate normally under a wide range of temperature and moisture conditions, it is very important for the early seedling growth and the whole grass seedling. Leguminous grass germination rate and germination rate are affected by temperature. Trifolium subterraneum