我县地处渤海之滨,冬季干冷少雪,春季多风少雨,春旱机率为80％左右。冬小麦的越冬期为101天,且冷冬年份多,负积温值≥-400℃的年份,出现频率为57％。因此,我县的冬小麦生产一直存在旱、寒等灾害的威胁。从二九七二年至一九八二年十年统计,历年越冬死苗率都在10％左右。个别年份死苗二成以上的面积占播种面积的20％ My county is located in the coast of the Bohai Sea, dry and cold in winter less snow, windy and rainy spring, spring drought probability of about 80%. The wintering period of winter wheat was 101 days, with more cold winters and negative accumulated temperature ≥-400 ℃, the occurrence frequency was 57%. Therefore, the winter wheat production in our county has been threatened by disasters such as drought and cold. Statistics from 1992 to 1982 indicate that overwintering dead seedlings rate is around 10% over the years. Individual year dead seedlings more than 20% of the area sown area of ​​20%