近50年河南省夏玉米生产潜力及产量差时空变化特征

Temporal-spatial variation of yield potential and yield gaps of summer maize during the past 50 years in Henan province

利用河南省96个县1961—2010年气象资料和夏玉米实际产量,采用逐步订正模型,计算了近50年河南省夏玉米光温生产潜力和气候生产潜力,分析了光温生产潜力与气候生产潜力、光温生产潜力与实际产量两种产量差的时空变化特征。结果表明:(1)光温生产潜力由北向南、由东向西递减,近50年呈极显著下降趋势,全省平均每10 a减少696.8 kg·hm-2,北、中大部分站点和南部的部分站点下降幅度较大。(2)气候生产潜力南部高于北部、东部高于西部,近50年变化趋势不明显。光温生产潜力与气候生产潜力之间的产量差呈极显著下降趋势,平均每10 a减少958.7 kg·hm-2。(3)夏玉米实际产量极显著增加,光温生产潜力与实际产量之间的产量差极显著下降,平均每10 a减少1 718.0 kg·hm-2,但71.9%的站点产量差大于24 000 kg·hm-2,产量潜力仍有较大提升空间。降水是制约河南省西部夏玉米产量的主要因素,可通过灌溉提高产量;后期热量不足影响北部玉米产量进一步提高,选用中早熟品种和改进栽培技术是提高产量的途径;东部可通过增加灌溉面积、选用优良品种和科学施肥等措施缩小产量差。

The objective of this study is to make full use of natural resources ,to analyze the yield potential of sum-mer maize in different regions in Henan province and to find the ways to bridge the gap between potential and actual crop yield .Based on daily meteorological observation data ,yield data of summer maize in 96 counties in the target region from 1961 to 2010 ,a successive correcting model was used to calculate photo-thermo productivity （YT ） and climate productiv-ity （YW ） and clarify the yield gap between YT and ΔYW ,the yield gap between YT and actual productivity （ΔYA ） ,the spatial-temporal characteristics of two types of yield gap in the past 50 years .The results showed that YT increased from the north to the south and form the east to the west of the province ,but it showed a diminishing trend during the past 50 years ,with a decreasing rate of -696 .8kg·hm-2·10a-1 .This is in particular obvious for most of the stations in north-ern and central areas and part of the stations in southern areas .ΔYW decreased obviously ,with a rate of -958 .7 kg·hm-2·10a-1 .The actual yield of summer maize increased significantly , while ΔYA decreased with a rate of-1 718 .0 kg·hm-2·10a-1 .The yield gaps were over 24 000 kg·hm-2 ,in 71 .9% of stations ,indicating a substantial yield potential .The precipitation is the key restricting factor on yield in the west of Henan province ,suggesting the ne-cessity of irrigation .The shortage of heat resources at later stage is the influencing factor in the north ,implying the im-portance of selecting early maturity varieties and improving agronomical practices in this area .In addition ,expending irri-gation area ,choosing suitable varieties and reasonable fertilization can be used to bridge the yield gaps in the east .