Change of Cultivated Land and Its Implications on Food Security in China

The population growth and demand for high living standard not only increase food demand but also cause more loss of the limited cultivated land resources. Cultivated land loss caused by disasters and the implementation of the ＂Conversion of Cropland to Forest or Grassland＂ project make this situation even worse in China. Thus, there is a problem to be solved imminently that to what extent the cultivated land can guarantee food security of China. Based on time-series data on food production and cultivated land area from 1989 to 2003 and other research results, this paper constructs quality index of cultivated land according to different land quality. Regression models are adopted to predicate changes of main factors from 2004 to 2030, which have great effect on cultivated land area or grain productivity, and verify accuracy with coc^cient of determination （R2）. Nine results were got according to three scenarios of decreasing rate of population growth rate and three cases of urban and rural built-up area per capita. There results show that China＇s food supply can only be maintained at a low to middle level of 370-410kg per capita, that is, China has enough land productivity to meet primary demand of food independently. However, it cannot reach the safe target of 500kg per capita if there is no breakthrough in breeding or no remarkable improvement of irrigation works, when the grain self-sufficiency maintains no less than 80%. To breed productive crops and to improve land productivity by mefiorating low quality cultivated land are appropriate measures to shrink the gap between food demand and supply. The results may offer helpful information for the formulation of policies on population growth, land use, protection of cultivated land.

Study on the Sustainable Use of Land-water Resources in Shandong Province of China Based on Food Security

After the analysis of food security of Shandong Province since 1990s, based on the change of grain output and per unit grain yield, it was considered that food production of Shandong Province was generally stable; through comparing the proportion of per capita possession of grains and per unit grain yield of Shandong Province in the whole country, it revealed that they were higher than the national average level. On this basis, the relationship between land-water resources and food security had been analyzed, and it summarized that Shandong water resources were insufficient, agricultural water was not enough and water had been seriously polluted; and that cultivated area was large and the overall quality was high. Meanwhile, it had analyzed the spatial pattern of land-water resources and the loss of water and soil. Finally, suggestions for the sustainable use of land-water resources in Shandong Province based on food security had been proposed. It should enhance the construction of basic agricultural facilities and implement united dispatching of multiple water resources; strengthen the supervision of cultivated land resources and comprehensively develop reserve resources of cultivated lands; and intensify the treatment of land-water resources and prevention of the loss of water and soil in key areas.

Food Security of Shifting Cultivation Systems: Case Studies from Luang Prabang and Oudomxay Provinces, Lao PDR

The Government of the Lao PDR’s policy is to eliminate the cultivation of upland rice by means of ‘slash-and-burn’ cultivation and to replace it with more ecologically stable systems based on sustainable land use at the village and household level. The objectives of this policy are to alleviate poverty and to introduce more sustainable management of agricultural resources. In order to achieve these objectives, the government has initiated a program of relocation to upland ‘focal areas’ from which marketing, distribution and other services can be supplied, these being essential preconditions for effective agricultural development in these regions. This diagnostic study has examined communal and household strategies for addressing food security issues, and has highlighted the main problems encountered in the pursuit of food security on the local level. The specific objective was to conduct a broadly focused participatory problem diagnosis of the study areas in two districts Phonsay and Namo, in order to understand farmers’ problems, livelihood goals and how their perspectives on food security have changed, and to investigate food security in shifting cultivation systems in Luang Prabang andOudomxay provinces. Within these two provinces Phonsay and Namo districts were selected as the research areas. The two districts are the poorest districts in the Luang Prabang and Oudomxay provinces and two of ten priority poorest districts in the whole country. Semi-structured interviews were conducted for the study. The results of this study were reviewed against the sustainable land use systems strategy formulated from the Lao PDR policy. The study highlights both the benefits and stresses on household welfare, food insecurity conditions in the study areas, and interrelated problems of insufficient rice for household consumption. Finally based on these results the authors propose recommendations and future research indications.

Analysis on the Influencing Factors and Control Measures of "Non-Grain Conversion" of Cultivated Land in Agricultural Land Transfer

Through the method of literature analysis,this paper analyzes the present situation of the"non-grain conversion"of cultivated land in the transfer of agricultural land in China,summarizes the influencing factors and consequences of the phenomenon of"non-grain conversion"of cultivated land in the transfer of agricultural land,and finally puts forward some measures.The study found that costs and benefits are the fundamental factors affecting the"non-grain conversion"of cultivated land in agricultural land transfer,and other main factors include government and policy guidance,industrial and commercial capital to the countryside,labor transfer and so on.The"non-grain conversion"of cultivated land in the transfer of agricultural land is a serious threat to China s food security,leading to the decline of the quality of agricultural land and the destruction of the ecological environment,as well as the risk of breach of contract in"industrial and commercial capital to the countryside".Based on the understanding of the influencing factors of non-grain conversion,this paper puts forward the following measures:strengthening the control of the use of cultivated land in agricultural land transfer;implementing accurate subsidies for grain cultivation and ensuring the benefit of grain growers;adopting grain planting incentive mechanism to increase grain enthusiasm;strengthening media publicity and education to enhance food security awareness.The improvement of the current situation of the"non-grain conversion"of cultivated land in the transfer of agricultural land will be of great significance to the protection of agricultural land and food security in China.

粮食安全视域下耕地生态补偿的法治化进路研究

耕地生态补偿的法治化契合了粮食安全和生态文明法治保障体系建设的内在要求。我国尚未制定耕地生态补偿专门性法律法规,《耕地保护法(草案)》对于耕地保护补偿制度的设计还存在诸多疏漏,未对耕地生态补偿制度予以明晰表达。为推动耕地保护,进而保障粮食安全及可持续发展,需要着眼于耕地生态补偿制度建构的权利基础,证成耕地生态补偿制度构造的正当性,厘定耕地生态补偿制度的属性特质,进而着眼于补偿请求权主体、补偿标准、补偿方式、补偿监督等多维度,对耕地生态补偿予以法治构造。

高标准农田建设能遏制耕地“非粮化”吗?

把高标准农田建设作为一项准自然实验,构建连续型双重差分模型,基于省级面板数据考察高标准农田建设对耕地“非粮化”的影响及作用机制。研究发现:相较于控制组,高标准农田建设使实验组耕地“非粮化”程度下降了3.64%,表明高标准农田建设对耕地“非粮化”具有显著且持续强化的抑制效应,经过模型适用性和多重稳健性检验后结果依然可信;该政策效应因区域粮食功能定位、粮食熟制、粮食作物种类和地形条件不同而表现出明显差异,粮食主产区、高熟制地区、水稻主种植区和非平原地区高标准农田建设对耕地“非粮化”的抑制效应更明显;地块规模扩张、种植模式变革和比较成本优势是高标准农田建设抑制耕地“非粮化”的三条重要途径。研究结论的政策启示为:在建设农业强国过程中,应加快新一轮高标准农田建设,尽快补齐耕地质量短板;同时严格落实高标准农田利用优先序,彻底扭转耕地“非粮化”势头,为实现“藏粮于地”战略目标提供支撑。

基于GlobeLand30数据的中国耕地与粮食生产的时空变化分析

21世纪初期,中国耕地与粮食产量变化区域差异明显,为了解21世纪初期中国耕地与粮食生产的时空变化及粮食生产对耕地面积变化的响应,该文利用2000年和2010年两期30 m分辨率的全球地表覆盖数据(Globe Land30),借助统计分析手段对2000-2010年中国耕地和粮食生产的时空变化和粮食生产对耕地面积的依赖程度进行分析。结果表明:1)中国耕地主要分布在东部地区,研究时段内,耕地与林地、草地和人工表面之间的转换最多,耕地变化的特点是"西增东减,总量减少",面积净减少了104.03万hm2,年均减少10.4万hm2。2)中国的粮食生产主要集中在东北、华北和南方地区。粮食产量变化的特点是"北增南减,总量增加"。3)中国耕地分布的集中程度会影响粮食生产的集中程度,且粮食生产分布的集中程度普遍高于耕地。中国耕地分布重心和粮食生产分布重心的移动方向相反,耕地面积的分布表现出了"南退西移"的趋势,粮食生产的重心则是"北上东移",中国的粮食生产格局已转变为"北粮南调"。4)全国有32.24%县(市)的粮食生产都表现出了对耕地数量的依赖,主要分布在东北、华北、西部、长城沿线、西南和东南沿海地区。中国耕地保护政策的制定和粮食生产的可持续发展应该遵循因地制宜的原则,在粮食生产对耕地变化敏感性高的地区,应该加强对耕地数量、质量的保护和农户种粮积极性的提高,更要重视不敏感地区耕地地力的保护和单产水平的提高,以保障中国的粮食安全。

东北三省粮食需求量预测与未来黑土地耕地质量提升思考

明确东北三省未来粮食需求走势,对保障国家粮食安全、保护利用东北黑土地资源具有重要指导意义。从国家粮食供需平衡角度,综合考虑宏观经济条件和农业生产条件,预测分析2023-2032年黑龙江、吉林、辽宁3个省份的粮食需求量可以为量化保障国家粮食安全、高效利用黑土地资源提供基本依据。依据粮食供需均衡原理,基于深度学习的多种农产品供需预测模型,以LSTM(长短时记忆神经网络)对2023-2032年中国粮食需求量进行预测,并引入黑龙江、吉林、辽宁各省的粮食承载系数,计算出各省粮食需求量,对满足未来粮食单产增加需求的黑土质量提升进行预判。随着社会经济发展和人口变化,2023-2032年东北三省各省的粮食需求量均稳中有增,其中稻谷需求量变幅不大,玉米和大豆需求量增幅明显。预计2032年,黑龙江、吉林、辽宁三省玉米需求量比2022年分别增长10.9%、23.2%、24.8%,吉林省和辽宁省未来10年的玉米需求量增幅明显高于黑龙江省;黑龙江、吉林、辽宁三省大豆需求量将比2022年分别增长47.7%、39.1%、34.8%,黑龙江省2023-2032年的大豆需求量的绝对值和增幅均最高。东北三省未来粮食需求呈增长趋势,受粮食消费结构持续变化影响,玉米、大豆需求增幅较大。基于此,未来东北三省要多途径提升粮食单产,以提升黑土耕地质量为基础,进一步筑牢国家商品粮生产基地,为保障国家粮食安全提供坚实基础。

近20年河南省耕地非粮化时空分异及驱动力分析

耕地是育种成粮的基础条件,研究耕地非粮化的时空演变格局及驱动因素,对于严格保护耕地、保障国家粮食安全具有重要意义。基于河南省2000—2020年土地利用数据,利用标准差椭圆模型、热点分析、地理探测器等方法对河南省耕地非粮化水平进行了时空演变分析和驱动因子探测。研究结果表明:(1)2000—2020年间河南省耕地非粮化面积达到3007.10 km2,占现状研究区耕地总面积的2.90%,尤以2015—2020年最多;其中信阳市的耕地非粮化面积最多,达到754.14 km2,占耕地非粮化总面积的25.08%。(2)2000—2020年间耕地非粮化热点区域集中在研究区的西部和南部,耕地非粮化重心主要分布在平顶山市,重心整体向南迁移。(3)河南省耕地非粮化受农业、经济和社会因素的共同影响,农业因素对研究区的耕地非粮化影响力较大,任一影响因子与其他因子交互作用表现出双因子增强和非线性增强效果。河南省耕地非粮化呈现出明显的时空分异特征。

粮食安全视角下耕地“非粮化”现状及管控措施研究——以海西州乌兰县为例

耕地是粮食生产的根基,在粮食安全背景下,耕地“非粮化”问题受到广泛关注。为全面诠释乌兰县耕地“非粮化”问题,本文基于地方统计公报对乌兰县“非粮化”现状、驱动因素、管控措施进行了全面分析。研究得出,乌兰县“非粮化”比重偏高、主导类型明显、空间差异大,其驱动因素主要有粮经作物收益差值大、优质耕地少、当地特色产业突出等。针对其驱动因素提出了完善种粮惠民政策、推进耕地规划和中低产田改造项目、实行分区管控等遏制耕地“非粮化”的管控措施,以期为乌兰县耕地“非粮化”问题治理提供借鉴和参考。

大食物观下多元化食物供给和耕地保护协同推进:逻辑、机制与路径

研究目的:阐述多元化食物供给和耕地保护协同推进的逻辑、机制及路径,为新时代粮食安全问题提供新思路。研究方法:理论分析法、归纳演绎法。研究结果:(1)协同推进多元化食物供给和耕地保护是新时代粮食安全战略转型的本质要求、国家生态文明建设的核心需求、中国式农业现代化建设的必由之路及应对全球复杂格局的必然选择。(2)多元化食物供给和耕地保护协同推进具有理论同源性、根本目标一致性、核心价值同一性和实践过程联动性。(3)新时代耕地保护必须注重与山水林湖草沙全域全要素空间配置,要素重组、空间重构、产业重塑是大食物观下多元化食物供给和耕地保护协同推进的激活机制。(4)未来应从双轮驱动政策体系、耕地利用转型、食物消费结构多元化和创新全产业链利用模式等方面促进多元化食物供给和耕地保护协同推进。研究结论:大食物观下多元化食物供给和耕地保护协同推进有助于保障新时代国家粮食安全,对耕地保护转型和制度创新具有重要指导意义。

北方农牧交错带耕地压力时空演变规律及预测

[目的]研究中国北方农牧交错带耕地压力时空演变状况及空间分异状况,为北方农牧交错带未来粮食安全发展战略布局提供决策参考。[方法]基于修正的耕地压力指数模型分析北方农牧交错带2000—2023年耕地资源状况,并细分研究区域,分析耕地压力时空发展态势,利用预测模型测算耕地压力未来变化状况,最后提出相应对策建议。[结果](1)北方农牧交错带耕地压力总体上升,在时间序列上呈现“W”形变化;空间格局呈现“整体警戒,局部平稳”的态势,压力重心随时间总体向西南迁移;(2)区域耕地压力异质性呈逐渐分异趋势,受区域功能及产业结构发展的影响,时间格局上呈现异质性逐渐明显的趋势,空间格局分布上呈现出“长城沿线沙化地区长期稳定,黄土丘陵沟壑地区逐渐上升,京津冀水源涵养地区平缓下降”的特征;(3)未来7 a北方农牧交错带耕地压力呈现整体升高态势,对粮食安全及区域发展构成一定威胁,需引起有关部门的保护及重视。[结论]北方农牧交错带耕地压力总体呈上升趋势,且区域内差异逐渐明显,未来应提高全域耕地地力及环境整治能力,开展跨区域耕地保护补偿机制。

粮食安全视域下的耕地概念探讨

聚焦我国耕地资源国情,从保障安全视域出发,分析粮食安全内涵变化过程中对耕地资源保障的需求,通过对国际上耕地概念的概述和从历史、常识、法律、技术等角度对耕地概念的理解,提出完善耕地概念的建议,采用定量分析法、实证分析法、逻辑分析法、历史研究法,以期为加强粮食安全耕地保障能力提供参考。现行耕地概念过于强调技术逻辑,在我国农业生产土地资源趋紧的条件下,并不利于我国的粮食安全和居民生活水平提升,尤其是园地与耕地都以生产食用农产品为主导功能。有必要适应我国农业特别是种植业发展的需要,让耕地概念回归本义与常识,将园地等支撑种植业发展的土地资源纳入耕地范围,并赋予耕地概念管理逻辑和规划属性。研究结论:统筹法理逻辑、管理逻辑、技术逻辑与常识认知,将耕地概念界定为“用于种植农作物的土地”,形成对国家粮食安全整体利益价值追求。

耕地细碎化对农户种植业收入的影响——“非粮化”和耕地流转率的调节效应

耕地细碎化会导致农户种植活动的分散化,减少了农户的有效劳动时间,并阻碍了机械化作业的开展,不利于种植业的增产增收。采用“全国农村固定观察点调查”2009—2020年的面板数据,以种植主导型农户为研究样本,分析发现:农户的耕地细碎化程度提高对其种植业收入具有显著的负向影响,该结论在经过一系列稳健性检验和内生性处理后依然成立;家庭种植结构“非粮化”和村庄耕地流转率提高可以显著弱化耕地细碎化对农户种植业收入增长的抑制作用;相对而言,耕地细碎化对化肥施用强度较高农户、老龄化程度较高农户、丘陵山区农户的种植业收入具有更强的负向影响。因此,应促进耕地流转市场发育,加强农村土地整治,提高粮食生产比较收益,推动化肥农药使用减量增效,拓展优化农业社会化服务,在降低农户耕地细碎化程度的同时,有效缓解耕地细碎化对农民收入增长的抑制作用。

Exploring differentiated improvement strategies of cultivated land quality in China

Quality is the core feature of cultivated land. In the face of deteriorating cultivated land quality and growing food demand, improving cultivated land quality is a top priority for guaranteeing the sustainable use of resources and national food security. Cultivated land quality in the new era can be considered in four dimensions: suitability, contiguity, resistance and ecological stress. Cultivated land suitability in China shows a decreasing trend from east to west, cultivated land contiguity is high in the north-east and low in the south-west. In terms of cultivated land resistance, the number of strongly and weakly resistant cropping fields is small and spatially clustered. Cultivated land with ecological stress is mainly located in the northern region. Based on the current situation of cultivated land quality and the strategic needs of national high-quality development, China's future goals for improving cultivated land quality include four aspects: promoting the sustainable use of resources,improving the economic benefits of farming, coping with extreme meteorological disasters and meeting the transition of the food system.Against the backdrop of a volatile international environment and high domestic demand for food, China should guarantee a safe supply of staples, a stable supply of animal feed and a moderate supply of high-nutrient food. In the future, China should create three major food production spaces: highstandard, low-to medium-yield, and marginal cultivated land. China urgently needs to construct three paths to implement the goal of improving cultivated land quality, namely the development of high-standard cultivated land with the core of spatial optimization, resilience enhancement and scale coupling,the transformation of low-to medium-yield cultivated land with the core of obstacle elimination, tenure adjustment, ecological sustainable, and the conservation development of marginal cultivated land with a focus on sustainable use.

大食物观统筹下的耕地保护协同治理体系研究

随着我国经济社会的快速发展和食物需求结构的转变,耕地保护制度在维护国家粮食安全和促进区域协调发展中的作用愈发凸显.从大食物观的提出及其与耕地保护的关系出发,分析了当前耕地保护面临的诸多挑战,如食物需求结构转型、区域分工协同需求以及耕地后备资源的稀缺性.在总结我国耕地保护成效与不足的基础上,深入探讨了耕地安全的基本事实,粮食安全现状与耕地保护目标之间的差距,以及耕地保护效能降低的原因,并识别了耕地保护面临的机遇与挑战.针对这些问题,提出了一系列创新路径,包括加强土地资源调查、优化占补平衡政策、建立区域补偿机制和第三方评估体系等,以期为构建大食物观统筹下的耕地保护协同治理体系提供政策参考.

山区耕地利用碳排放与粮食安全的耦合协调研究

为探究山区耕地利用过程中实现减排增汇与保障粮食安全权衡/协同的发展,以典型喀斯特地貌分布的贵州省为研究区,构建山区耕地利用碳排放量评估的方法体系,测算2010—2022年贵州省耕地利用碳排放效率和粮食安全水平,并利用耦合协调度模型阐明碳排放效率与粮食安全的关系与时空演变特征。结果表明:1)近13年来贵州省耕地利用碳排放量呈“西高东低、北高南低”,先升后降趋势,化肥使用产生的碳排是耕地利用过程中碳排放的主要来源之一,也是山区耕地碳减排的关键。2)2010—2022年贵州省耕地利用碳排放效率呈先下降再上升趋势,总体水平不高,各市(州)差异明显,呈西北高、东南低的特征。3)2010—2022年贵州省粮食安全水平均值从0.510上升至0.537,呈“下降—上升”趋势,处于临界安全级别,空间上呈北高、南低的特征。4)2010—2022年贵州省耕地利用碳排放效率与粮食安全的耦合协调度总体由“勉强协调”向“初级协调”发展,各市(州)耦合协调度均有提升,但北部明显高于南部。建议贵州省结合山区耕地特点,深化农业产业结构,大力推广先进绿色的耕种技术,实现耕地利用碳减排和粮食安全的协调可持续发展。

面向粮食安全的耕地“三位一体”保护——政策演进、现实困境与优化路径

保障粮食安全,根本在耕地。文章梳理了耕地数量、质量、生态“三位一体”保护的政策脉络和体系框架,发现耕地保护工作面临诸多现实困境,包括耕地保护主体积极性不高、耕地占补平衡制度待完善、耕地质量提升难度较大、耕地高强度利用问题突出。基于此,提出粮食安全视角下耕地保护的优化路径:完善耕地保护激励约束机制,完善耕地占补平衡制度,强化高标准农田建设资金保障,提升耕地资源可持续利用能力。

基于粮食安全视角的喀什地区耕地“非粮化”影响因素及监管对策研究

[目的]基于粮食安全的视角,分析喀什地区的耕地“非粮化”特征、耕地供需盈亏情况以及耕地“非粮化”的影响因素,并提出耕地“非粮化”的监管对策建议。[方法]基于实地调查及统计数据,分析喀什地区1995—2020年耕地“非粮化”时空演变特征,运用粮食供需平衡法分析喀什地区的耕地供需盈亏情况以及耕地“非粮化”的安全区间,构建耕地“非粮化”影响因素指标体系,使用二元Logistic回归模型分析各影响因素对耕地“非粮化”的影响程度。[结果](1)1995—2020年,喀什地区的耕地“非粮化”率及“非粮化”面积的时空演变趋势基本一致,在1995—2014年呈波动中上升的趋势,2014年后呈波动中下降的趋势,空间演变特征呈现东北高,西南西北低的分布格局。(2)在研究期内,只有喀什市长期处于耕地供给赤字状态,塔县于2010年处于耕地供给赤字状态,其余县市均处于耕地供给盈余状态;喀什市的耕地“非粮化”率已严重超过安全区间,喀什地区的其余区域均处于安全区间范围内。(3)家庭农业劳动力、农户兼业化程度、农资价格变化、种粮补贴政策效果对耕地“非粮化”的影响显著,其余影响因素对耕地“非粮化”的影响不显著。[结论]喀什地区耕地“非粮化”水平较高,耕地供给不平衡,应完善区域耕地保护政策,制定差别化的管理策略,遏制耕地“非粮化”现象继续蔓延,实现粮食安全与耕地安全的可持续发展目标。

耕地“非粮化”驱动系统分析

日益凸显的耕地“非粮化”问题对耕地资源保护和粮食安全保障产生威胁,识别“非粮化”驱动因素及其作用路径,对于构建逆“非粮化”策略意义重大。论文借助多元线性回归分析与系统动力学模型,分析非粮现象的驱动系统,探讨“非粮化”治理策略。研究发现:(1)中国耕地“非粮化”现象演化由机会成本与对外贸易等因素综合驱动,具体表现为农业发展水平、农民经济收入和对外贸易依存度驱动了“非粮化”现象上升,生产条件的改善则有利于抑制非粮化。(2)仿真目前政策情景发现,粮食生产者囿于低效益,“非粮化”现象愈演愈烈。(3)仿真逆“非粮化”政策情景发现,针对粮食补贴、生产成本和贸易策略,降低生产成本,可以遏制非粮趋势,维护粮食安全。建议在短期治理中,可以依靠精准化粮食补贴与动态化粮食收储遏制非粮选择;在长期治理中,要依靠现代化农业生产提高生产效率,促进种粮积极性,加快防控“非粮化”的步伐。