我县是一个农业县,位于喜马拉雅山脉与冈底斯山脉之间的藏南谷地,雅鲁藏布江横穿全县中部。农区大部分布在海拔3500—4300米之间,无霜期110—150天,年降雨量400mm左右。农作物以小麦、青稞为主,一年一熟。冬春季节,是冬小麦经受严重考验的关键时期,全县每年都不同程度的遭受冻害而死亡。为了防止、减少冬春麦苗死亡的发生,我们于1978年12月下旬进行了压土(冻河泥土)试验。试验结果表明:冬季压土不但能有效地减少小麦冬春冻害死苗,而且能够提早返青出苗整齐、苗壮、分蘖力强。据我们对“农大139”和“北京10号”二个小麦品种观察,其结果见表1、表2: My county is an agricultural county located in the southern Tibetan valley between the Himalayas and the Gangdise Mountains, and the Brahmaputra across the middle of the county. Most of the rural areas are distributed at an altitude of 3500-4300 meters, with frost-free period of 110-150 days and annual rainfall of about 400mm. Crops to wheat, barley-based, cooked a year. Winter and spring are the critical period for winter wheat to undergo serious tests. Every year, the county dies of frost damage to varying degrees. In order to prevent and reduce the occurrence of the winter and spring wheat seedlings death, we carried out the crushed earth (frozen earth) test in late December 1978. The test results show that the winter pressure soil can not only effectively reduce winter winter and spring cold damage of dead seedlings, but also can early return to green seedlings tidy, strong seedlings, strong tillering ability. According to our observation of two wheat varieties “Nongda 139” and “Beijing No. 10”, the results are shown in Table 1, Table 2: