中文摘要：

研究了内蒙古地区的气温及土壤温度变化情况对牧草种子播期选择的影响。通过对内蒙古呼和浩特地区4至8月的气温及不同土层处温度的测定和研究，建立了气温与不同土壤播层温度的预测关系式。研究结果表明：确定牧草种子适宜播种时期的温度限制因子不仅仅是低温，高温的限制作用可能更为严重。因此，建议在内蒙古呼和浩特地区进行牧草种子播种期的选择，要考虑到高温对种子萌发及成苗的影响。对内蒙古其他地区，也可根据当地气温测定值，利用预测公式进行估算不同时间的播层温度，以确定牧草最佳播种时期。

英文摘要：

This study investigated the changes of ambient temperature, soil their potential impacts on seed germination and seedling emergency during temperatures at different layers and sowing season. Relationships among ambient temperature and temperatures of different soil layers were established. Research on ambient and soil temperature changes during the period from April to August indicated that high temperature was an important. stressous factor affecting seed germination. It was suggested that determination of sowing season in Huhhot region should consider the negative effects of high temperatures as well as low temperatureS. End of May to early July is the suitable sowing time for Hohhot area. Suitable sowing times for other regions in Inner Mongolia can be determined from ambient temperatures using the regression formula in formed in this research.