1976年是我区自解放以来水稻冷害最严重的一年。当年水稻各主要生育期显著推迟,穗大粒多,但有效分蘖穗数少,空壳多,秕粒少,有雌蕊单性结实现象发生,结实颖花数显著减少。据区农科所和本站在青铜峡、中卫、中宁、吴忠、灵武、贺兰六县调查结果,水稻空壳率一般在30～90％,也有几乎颗粒不收的。空壳率如此之高,是历史上 1976 is the most serious year of rice cold damage since liberation in our district. In that year, the main growth periods of rice were postponed significantly, with more spikes and large grains. However, the number of effective tillers was less, the number of shell was smaller, the number of grains was smaller, the parenchyma of pistils occurred, and the numbers of stout spikes reduced significantly. According to the survey results of the six districts of Qingtongxia, Zhongwei, Zhongning, Wuzhong, Lingwu and Helan, the agricultural institutes and stations in this area generally have 30-90% of the empty shell rate of rice and almost no grain. Shell rate is so high, is history