关键词: 玉米, 玉米, 遮阴, 氮肥, 硼肥, 产量, 农艺性状

Abstract: To understand the variation characteristics of precipitation in the eastern part of northwest China, and to provide a theoretical basis for the implementation of poverty alleviation strategies in response to climate poverty, based on the precipitation data of 81 stations in eastern part of northwest China from 1961 to 2010, the authors analyzed the variation characteristics of precipitation in the area by using the climate trends, correlation coefficient, relative variability, Mann- Kendall and other methods. The results showed that: in recent 50 years, the annual precipitation significantly reduced in the eastern border of Shaanxi, Minxian- Lintao-Huajialing in Gansu and Guyuan in Ningxia, and the increased area was located in Delingha-Dulan- Tuole; the precipitation in spring significantly reduced in the middle, east and south of Shaanxi, the increased area was located in the middle, west and southwest of Qinghai; the precipitation in summer significantly reduced in western Hexi corridor, the increased area was located in the middle, west and north of Qinghai and southern Shaanxi; the precipitation in autumn significantly reduced in southern Shaanxi, the middle and south of Ningxia, southeastern Gansu, the increased area was located in northwestern Qinghai and western Gansu; the precipitation in winter was increasing (excepted for individual sites); the relative variability of seasonal precipitation was similar to that of the annual precipitation, the high value area was in northwestern Qinghai, the western Hexi corridor, and the low value area was in Qilian Mountains, southern Qinghai and southern Shaanxi; the precipitation in autumn and winter had mutations in the 50 years, the possible points of mutation were determined in 1975 and 1986.