粮食安全视角下粮食主产区耕地休耕规模及动态仿真研究

研究目的:以保障粮食安全为目标,构建粮食主产区休耕最大规模测算和仿真模型,仿真预测不同人口政策效应情景下最大休耕规模及休耕规模弹性边界,以期为保障中国休耕政策推行的科学性和合理性提供参考.研究方法:系统动力学模型.研究结果:(1)2007—2016年模拟期内,湖北省在兼顾区域粮食供给和保障国家粮食安全的同时,能够保有一定比例持续增长的弹性耕地资源,支撑国家"藏粮于地"战略的实施;(2)2017—2036年仿真期内,湖北省休耕最大规模和休耕规模弹性边界在人口增长保持不变和不断下降两种情景下总体保持扩张趋势,在人口增幅略微上升和大幅上升两种情景下呈现先缩小再扩大的态势;(3)在当前符合全面二孩政策目标人群规模庞大且妇女二孩生育意愿较强的情况下,全面二孩政策在中长期的粮食需求增加效应极有可能导致湖北省可休耕耕地规模减少和休耕规模弹性边界缩小.研究结论:应积极扩大休耕规模和范围,丰富休耕试点区域,正式建立目标多元化、模式多样化和实施常态化的耕地休耕制度,以粮食安全为前提实现对休耕的宏观调控.

Study on Fallow Scale and Dynamical Simulation of Major Grain Producing Areas in China from the Food Security Perspective

The purposes of this paper are to build a model to estimate the largest fallow scale of major grain producing areas in China aimed at ensuring food security, and to predict the largest fallow scale and elastic boundary of Hubei Province in different scenarios of the population policy effect. The system dynamics model is applied in this paper. The results show that: 1)during the simulation run from 2007 to 2016, a certain proportion of flexible cultivated land resource can still be held in Hubei Province to support the implementation of fallow after both regional grain supply and national food security are guaranteed;2)during the simulation run from 2017 to 2036, the largest fallow scale and elastic boundary of Hubei Province would keep expanding in scenarios where population growth remains the same and decreases constantly, and would shrink first and enlarge afterwards in two scenarios of population growth increase;3)currently, given the enormous size of the target population of two-child policy as well as the strong fertility willingness of most women in child-bearing age,the effect of the increasing grain demand generated by the universal two-child policy in the medium and long term would lead to the reduction of the largest fallow scale and shrinkage of elastic boundary. In conclusion, the governments are supposed to expand the fallow scale, enlarge the number of pilot areas, formally establish fallow system with multi-objectives, diversification mode and normalized implementation rules, and conduct the macro-control based on food security.