黄土高原半湿润区玉米生长发育及产量形成对气候变化的响应

Growth and Yield of Corn under Climate Change in the Semi-Humid Region of the Loess Plateau

利用黄土高原半湿润区西峰农业气象试验站玉米生长发育观测资料、加密观测和对应平行气象观测资料，分析气候变化对玉米生长发育的影响，以及玉米穗干重生长与气象条件的关系。结果表明，1951-2010年，试验区逐年降水量呈波动变化，20世纪90年代降水量较其他年代为最少。降水量序列3a、8a的周期变化特征明显。试验区逐年气温为上升趋势，逐年气温序列线性拟合气候倾向率为0．325℃／10a。逐年作物生长季干燥指数显著上升，逐年干燥指数序列线线性拟合气候倾向率为0．051／10a，进入20世纪70年代，试验区气候暖干化特征明显。气候变暖使玉米拔节一成熟期提前（5-6）d／10a，全生育期缩短。玉米穗干重在播种102d后，从缓慢生长期转为迅速生长期，在播种129d后，又从迅速生长期转为缓慢生长期，玉米穗的干物质积累最大速率出现在播后115d左右。气候变暖使玉米大部分生育期可利用热量资源充裕，玉米产量形成对抽雄-开花期气温变化十分敏感，大部分时段气温对玉米产量形成呈负效应。气温变化的影响函数与降水量变化的影响函数表现为反相位特征。在玉米成熟期，降水对产量的影响为负效应，其余生育期降水的影响为正效应，玉米产量形成对三叶-拔节期降水变化十分敏感。灌浆-成熟期光照对玉米产量形成呈显著的正效应。

Using corn growth and meteorological observation data, the effects of climate change on corn growth, and the relationship between ear dry weight growth and meteorological conditions were analyzed in a semi-humid region of the Loess Plateau. The results show that the interannual trend of precipitation in the study region fluctuated, and the average annual precipitation reached its minimum in the 1990s. An interannual periodic change of 3 a and 8 a was observed from 1951 to 2010. The interannual temperature trend was upward, and a linear fit of this trend produced a rate of 0.325℃/10 a. The crop aridity index during the growing season showed a marked upward trend, with a linear fit giving a rate of 0.051/10a. There was a significant drying and warming tendency from the beginning of the 1970s. Because of climate warming, the duration from jointing to maturing will be reduced by 5-6 days/10 a, the duration of the whole growth period has also a reducing tendency. The growth rate of ear dry weight was much greater on the 102nd day after sowing, and then reverted to a slow rate on the 129th day. The highest rate was on the 115th day. Because of climate warming, the amount of heat was abundant during most of the corn growing period. The yield was very sensitive to climate change during the period between tasseling to flowering. The precipitation influence and heat functions showed an opposite phase. Except for the maturation stage, precipitation was positively correlated with yield. Yield was also very sensitive to precipitation change during the seeding and three-leaf stage to jointing stages. Abundant solar illumination had a strongly positive effect on yield during the filling-maturing period. Long sunshine duration will aid the accumulation of dry materials.