基于Shift-Share模型的“镰刀弯”地区粮食增产结构变动分析——兼论玉米种植结构调整

STRUCTURE VARIATION OF GRAIN YIELD IN “SICKLE BEND” REGION BASED ON SHIFT-SHARE MODEL——AND THE ADJUESMENT OF CORN PLANTING STRUCTURE

[目的]"镰刀弯"地区玉米种植面积大幅度增加,粮食种植结构单一,为确保粮食安全稳定、多元化发展,需要明确该地区粮食生产结构中不同作物的变化特点和竞争优势。[方法]文章运用ShiftShare模型对"镰刀弯"地区的粮食作物生产结构和竞争力优势进行比较,分析了水稻、玉米、薯类、豆类以及其他作物的结构和竞争力优势差异。[结果]"镰刀弯"地区内部不同区域之间不同作物的结构优势和竞争力优势差异明显,其主要原因在于不同作物的播种面积和单位面积产量增长变动速度不同。[结论]"镰刀弯"地区粮食种植结构的调整,尤其是玉米种植面积的调减,应当充分考虑不同作物之间的优势差异,在满足可持续发展和市场需求且不形成过度供给的情况下,增加优势作物的种植,最终形成合理的种植结构和区域布局。

The ＂sickle bend＂ region is the main area of corn planting in China, including the northeast cool area, the northern farming pastoral zone, the northwest arid sandy area, the Taihang Mountain region and the southwest rocky dese desertification area. The planting area of corn in ＂ sickle bend＂ region increased greatly, which played an important role in ensuring food safety and stability, and hence it needed to clear the structure and competitive advantage of grain production in the area. The Shift - Share model was used in this paper to compare the production structure and competitive advantage in the ＂sickle bend＂ region, analyze the internal structure and the competitive advantages of rice, corn, tubers, beans and other crops. The results illustrated that： there were significant differ- ences in the structural and competitive advantages among different ＂ sickle bend＂ regions. The main factors were the different crop planting area and yield growth rate per unit area. Corn had the advantages of structure and com- petitive in the cool area of northeast China, the northwest arid region, and the southwest rocky dese desertification area. Rice and beans had competitive advantage in northeast China, while corn and tubers had competitive advan- tage in northern farming pastoral zone. In the Taihang Mountain region, tubers had competitive advantage, rice and beans lacked of structure and competitive advantage. Finally, it proposed that for the grain planting structure ad- justment, especially corn acreage, in the ＂sickle bend＂ region, it should fully take account into the differences of advantage between crops, and increase the area of the advantage crops under the condition of meeting the market demand, and ultimately perfect the layout of the regional planting structure.