基于比较优势分析法的冬小麦产量差异

在农户调查基础上，采用比较优势分析法对曲周县2003—2004年度冬小麦产量差异进行分析.调查数据表明，地块间小麦产量差异较大，产量范围为在4.2～7.9 t·hm-²，变异系数为0.14.通过逐步回归建立的由土壤盐碱度、土壤肥力、是否咸水灌溉、品种选择、返青期追施氮肥类型、播种时间、病虫害防治和返青期是否水分胁迫8个因子构成的产量差模型可以解释63%的产量差异.其中土壤盐碱度、土壤肥力和是否咸水灌溉是冬小麦的主要产量限制因子，其引起的产量差为727 kg·hm^-2，占总模拟产量差的52%.小麦品种引起的产量差为202.1 kg·hm^-2，占总模拟产量差的14%.播种时间、返青期追施氮肥类型、病虫害防治和返青期是否水分胁迫4个因子引起的产量差分别占总模拟产量差的7%、14%、10%和3%.因此，除土壤和气候状况外，管理措施也是造成产量差异的重要因素，通过优化管理措施可以大大减小产量差异.

Winter wheat yield gap between field blocks based on comparative performance analysis.

Based on a two-year household survey data, the yield gap of winter wheat in Quzhou County of Hebei Province, China in 2003-2004 was studied through comparative performance analysis (CPA). The results showed that there was a greater yield gap (from 4.2 to 7.9 t·hm^-2) between field blocks, with a variation coefficient of 0.14. Through stepwise forward linear multiple regression, it was found that the yield model with 8 selected variables could explain 63% variability of winter wheat yield. Among the variables selected, soil salinity, soil fertility, and irrigation water quality were the most important limiting factors, accounting for 52% of the total yield gap. Crop variety was another important limiting factor, accounting for 14%; while planting date, fertilizer type, disease and pest, and water press accounted for 7%, 14%, 10%, and 3%, respectively. Therefore, besides soil and climate conditions, management practices occupied the majority of yield variability in Quzhou County, suggesting that the yield gap could be reduced significantly through optimum field management.