湖北省大豆种植面积逆势恢复之谜：耕地禀赋约束下的农户作物替代优先序

RESEARCH ON COUNTERTREND RECOVERY OF SOYBEAN-PLANTING AREA IN HUBEI PROVINCE: FARMERS' CROP SUBSTITUTION PRIORITY ORDER UNDER THE CONSTRAINT OF FARMLAND ENDOWMENT

关键词:  大豆  种植面积  棉花比较效益  农户作物替代优先序  耕地水源禀赋

Key words:  soybean  planting area  comparative benefits of cotton  farmers' crop substitution priority order  endowment of farmland water source

摘要:

目的 提高大豆种植面积和产量是中国大豆振兴计划的核心目标。与许多省份不同，2014年以来位于非主产区的湖北省大豆种植面积“反常地”恢复至接近21世纪初的水平。方法 文章构建以耕地禀赋约束和农户作物替代优先序为基础的分析框架，从理论上解释湖北大豆种植面积恢复现象，并利用宏微观数据展开实证检验。结果 2010—2020年湖北大豆生产布局从山区与平原“平分秋色”转向江汉平原“一枝独秀”，江汉平原农户改扩种大豆是湖北大豆种植面积恢复的直接原因；籽棉价格持续下行或低迷致植棉比较效益偏低，诱发棉农作物替代是湖北大豆种植面积恢复的根本原因；水稻是江汉平原棉花的最优替代作物，但受耕地水源禀赋约束，条件较差的地块难以“棉改稻”，棉农只能改种次优的大豆、玉米等旱作作物；受土壤条件制约，江汉平原玉米较大豆并无产量和收益方面的压倒性优势，农户“棉改玉”和“棉改豆”倾向差异不明显。结论 该文对稳定和增加大豆面积，提升大豆自给能力具有一定的参考价值。

Abstract:

Enhancing both planting area and production of soybean is the primary target of China's Soybean Revitalization Plan. Unlike many other provinces, Hubei province, located in non-major production areas, has been witnessing its soybean planting area recover close to the level of the beginning of the new century since 2014. This research constructed an analytical framework based on farmland endowment constraint and farmers' crop substitution priority order, proposed a theoretical explanation for the above recovery phenomenon, and conducted empirical tests by using macro and micro datasets. The findings were listed as follows: (1) The layout of soybean production in Hubei province, during 2010 and 2020, shifted from equal distribution between mountainous areas and plains to domination of Jianghan Plain, suggesting that farmers' switch to or expansion of soybean cultivation in Jianghan Plain directly contributed to restoration of soybean planting area in Hubei province. (2) The root cause of this recovery lied in cotton farmers' crop displacement incurred by persistent decline or slump of seed cotton prices and the subsequent lower comparative benefit of cotton production activity. (3) While rice was the optimal alternative crop for cotton in Jianghan Plain, cotton farmers had to substitute suboptimal dryland crops such as soybeans and corn rather than rice for cotton in plots with poor irrigation conditions. (4) When substituting out of cotton, farmers acted out no distinct choice preferences between soybean and maize given that maize, in Jianghan Plain, had no overwhelming advantage upon both yield and benefit compared to soybeans under the limitation of soil conditions. So, this research provide a reference for stabilization and increase of soybean area, as well as enhancement of soybean self-sufficiency.