华北地区冬小麦产量潜力分布特征及其影响因素

摘要

APSIM-Wheat model was validated in regional level with crop data from agrometeorological observation stations in North China. Combining the daily climatic data during 1961-2007, the spatiotemporal distribution characteristics were analyzed in potential yield, water-restricted yield, and water-nitrogen-restricted yield of winter wheat to understand the influences of climatic factors on potential yield in different levels. The APSIM-Wheat model was proved to be applicable in North China. In the region, the potential yields of winter wheat in different levels showed a zonal distribution in space with a generally temporal decline; however, the differences of spatial distribution characteristics were distinct among yield levels. The decreasing trends were from northeast to southwest in potential yield of winter wheat, from southeast to northwest in water restricted yield, and from west to east before a decreasing from east to west in water and nitrogen restricted yield, with the maximum values in Jining, Shandong Province. Hebei Province was located in the zone of high values of potential yield and water and nitrogen restricted yield but low value of water restricted yield, where irrigation was the main factor to improve the yield of winter wheat. Shandong Province was in the zone of high values of potential yield and water restricted yield but low value of water and nitrogen restricted yield, where nitrogen fertilizer was the main factor to improve the yield of winter wheat. Henan Province was a zone of low value of potential yield, where radiation was a main restraint. The total radiation during the growing season was a major climatic factor that determined the spatiotemporal distribution characteristics of the simulated potential yield of winter wheat, and it was positively correlated with the potential yield (P < 0.01). Precipitation during the growing season was the most important climatic factor for distribution characteristics of water restricted yield, which was positively correlated with water restricted yield (P < 0.01). In contrast, the variance of water and nitrogen restricted yield explained by climate factors was only 0.48, suggesting that soil factors were determinative rather than climatic factors. Under the background of changed climate and unchanged varieties of winter wheat, the potential yields at different levels showed declining trends which resulted from the decrease of radiation and the increase of accumulated temperature during wheat growing season. The primary climatic factors for determining the distribution characteristics of winter wheat yield were total radiation and precipitation.%利用华北地区农业气象观测站作物资料,验证APSIM-Wheat作物模拟模型区域尺度有效性,结合1961-2007年47年逐日气候资料,分析冬小麦潜在产量、水分限制产量和水氮限制产量时空分布特征,明确了气候因素对冬小麦不同等级产量潜力分布特征的影响程度.对APSIM-Wheat模型在华北地区区域尺度上进行验证,结果显示区域化模型在华北地区有较好的适用性.华北地区冬小麦各层次产量在时间上总体呈下降趋势,空间上呈带状分布,不同层次产量空间分布特征有所差别:冬小麦潜在产量从东北向西南减少,水分限制产量从东南向西北递减,水氮限制产量从东向西先增加后降低在山东济宁地区达到最大;河北省为冬小麦潜在产量和水氮限制产量的高值区,同时为水分限制产量的低值区,增加灌溉是提高其产量的主要途径;山东省为冬小麦潜在产量和水分限制产量的高值区,水氮限制产量的低值区,增施氮肥是提高其产量的主要途径;河南省为冬小麦潜在产量的低值区,辐射是其主要限制因素.决定冬小麦潜在产量时空分布特征的最主要气候要素为生长季内总辐射,总辐射与潜在产量呈极显著正相关关系;决定冬小麦水分限制产量分布特征的最主要气候要素为冬小麦生长季内降水量,呈极显著正相关关系;气候要素对于冬小麦水氮限制产量空间分布特征的解释方差较小,仅为0.48,故土壤等其他因素对其空间分布影响较大.气候变化背景下,如不改变作物品种,冬小麦各级产量潜力呈下降趋势,造成其下降的主要原因为总辐射下降以及随积温增加冬小麦生长季缩短,决定冬小麦产量潜力空间分布的主要因素为总辐射和降水量.