甘肃省冬小麦水分适应性动态变化分析

Dynamic Variation of Water Adaptability of Wheat in Gansu

运用甘肃省西峰、天水农业气象试验站及环县等8个农业气象观测站1981年～2006年冬小麦生育期观测资料及西峰等14个气象站1971年～2006年气象资料,建立了估算水分适宜性的水分适宜度模式。计算分析表明,甘肃省冬小麦种植区水分适宜度地域分布差异较大,其中以陇东南的徽成盆地、天水南部适宜性最好,陇东北部适宜性最差,陇东南地区平均比陇东偏高0.14。其年代际变化为:20世纪70年代偏高,80年代偏低,90年代偏高,21世纪初又开始偏低。冬小麦各生长发育阶段适宜性随时间变化较大,冬前生长期的水分适宜度以每10年0.02～0.03的速度上升,越冬期的水分适宜度以每10年0.01～0.02的速度下降。在冬小麦全生育期中,越冬期及拔节阶段的水分适宜性最好,旺盛生长阶段的水分适宜性最差,初夏阶段冬小麦的水分供需矛盾,是冬小麦生长发育的主要胁迫因子。

A model of water adaptability for wheat was designed using experimental data from Tianshui and Xifeng agro-meteorological experimental stations and Huanxian and 7 other agro-meteorological observation stations in Gansu Province from 1981 to 2006, and meteorological data in Xifeng and 13 other weather stations from 1971 to 2006. The relationship between the dynamic variation of water adaptability and wheat yield was analyzed with the model using yield data from test fields of the Agro-meteorological Experimental Stations of Xifeng and Tianshui from 1981 to 2006. It has been proved that the model is a good measure for estimating the contribution of water to wheat yield. The results showed that there is high regional variation in water adaptability, with the maximmn degree of water adaptability in Hui-Chen Basin and southern Tianshui, while the minimum degree of water adaptability is in northeast Gansu, and the difference in average value between the two areas is 0.14. The degree of water adaptability was higher in the 1970s, lower in the 1980s, higher in the 1990s and then lower from 2000 onward. The range of variation in water adaptability for wheat was large in every growth period in terms of spatial and temporal distribution, with no evidence of temporal variation in water adaptability in the jointing period and the growing-flourishing period and an increase in water adaptability at a rate of（0.02- 0.03）/10yr in the period of autumn growth and a decrease at the rate of（0.01 -0.02）/10yr in the overwintering period. Water adaptability is best in eastern Gansu Province during autunm growth and maturation and in southeast Gansu during jointing and overwintering periods. Water adaptability is the lowest throughout the whole wheat-planting area during the growing-flourishing period. Water is the major stress factor for wheat production during the period of early summer.