宁夏山区春季降水对冬小麦生长发育的影响

Impact of Spring Precipitation on the Growing Period and Production of Winter Wheat in Ningxia Southern Mountain Region

选取宁夏南部山区固原和隆德2个有代表性站点的冬小麦测定资料作为样本,分析有记录以来冬小麦生长关键期3～5月的降水量、观测地段冬小麦发育期及产量资料,采用相关分析法分析降水对发育期和气候产量的影响。分析表明:降水是该区域冬小麦生长发育及产量形成的主要限制因子,固原3月各旬有效降水量3 mm以上,降水与返青期距平值呈正相关,隆德3月中旬有效降水量5mm、下旬3 mm以上相关显著。固原孕穗、抽穗、开花期发育期距平分别与5月各旬降水量相关显著。南部山区冬小麦气候产量与3月下旬、5月中下旬降水量具有显著的正相关关系。南部山区在春季降水异常的年份中,降水量偏少比降水量偏多对冬小麦减产影响明显;在冬小麦生育后期,降水是影响冬小麦产量的主要因素。

We selected the measurement data of winter wheat and precipitation observations from March to May in Guyuan and Longde as statistical samples to analyze the impact of precipitation on growing periods of winter wheat and climatic productions by using correla- tion analysis method. Resuhs show that the effective precipitation was the most important factor for the climate output of the winter wheat. If the precipitation was over 3 mm in every ten - day in March, the winter wheat would start to grow in Guyuan region. In Long- de, the precipitation over 5 mm in the second ten - day and 3 mm in the last ten - day of March correlated positively with growing peri- od of winter wheat. The late growth period anomaly of winter wheat in Guyuan highly related to the precipitation in May. The climate outputs of winter wheat in south mountain region correlated positively with precipitation in the last ten - day of March and the second and the last ten - day of May. And in the south mountain region, the influence of less precipitation was more obvious than that of more precipitation in spring on winter wheat outputs. During the late growth period, the precipitation was main influence factor for winter wheat outputs.