Characteristics of Steep Cultivated Land and the Impact of the Grain-for-Green Policy in China

The Grain-for-Green Policy in China could not only improve China's ecological quality, but also influence grain supplies for a short term. Based on data from the detailed nationwide land use survey in 1996 and the steep cultivated land survey update in 2000, a regression model for the driving forces affecting steep cultivated lands was developed, and cluster analysis was used to identify seven steep cultivated land types in order to analyze the grain availability impact of the project with land usage estimates for 2010 and 2030. The results suggested that consecutive days with minimum daily temperature over 10℃ and the dominant slope in a county constrained the spatial distribution of steep cultivated lands. In terms of socioeconomic factors, steep cultivated land was a complex interaction of population size, gross domestic production level, and the richness and quality of cultivated lands having slopes less than 15°. The trends for steep cultivated land in 2010 and 2030 were forecast using a driving forces model and China's grain security criteria and showed that the Grain-for-Green Policy at the national level would not cause a grain shortage or threaten food security criteria. However, if steep sloped lands were to be retired from production, some regions would need grain supplements as early as 2010. Also, assuming that only 60% of the cultivated land at the national level was needed, population and economic development pressures in 2030 would require some steep cultivated lands to be used for grain production.

Long-term Dynamics of Cultivated Land Resources and Their Driving Forces of Guyuan City in Upper Reaches of Jinghe River

The land use patterns in Guyuan City,Ningxia Hui Autonomous Region of China,have changed greatly over the years,due to population growth and farming and stock raising development.This study,using 50-year statis-tical data of cultivated land and 14-year spatial data of land use pattern,analyzed the developmental stages,the char-acter,and the spatial variance of farmland in the city,and discussed the driving forces of cultivated land changes based on empirical and conceptual statistical models.First,the change of cultivated land area went through different stages of rapid increase,fluctuating change,decrease and rapid decrease from 1949 to 2004,additionally,social and economic policies in different stages had an important impact on farmland variance.Second,from 1986 to 2000,the quantity of cultivated land increased,but its quality decreased.Third,social and economic factors are determinant factors in culti-vated land transition.Five constructed paths explain cultivated land transition.Factors that have direct or indirect ef-fects on farmland include the economy(Xeco),the population(Xpop),agricultural output(Xagr),and scientific input(Xsci).The sequence of impact was Xeco>Xpop>Xsci>Xagr.Among all these impacts,Xeco was the major positive one,and Xpop was the major negative one.It is urgent to take measures or adopt a policy to stop the vicious cycle in eco-environment and agriculture production.Otherwise,negative patterns of farmland use will increase,and high-quality cultivated land will continue to decline.

Cultivated-land change in Mu Us Sandy Land of China before and after the first-stage grain-for-green policy

Mu Us Sandy Land(MUSL) of China, as a typical eco-fragile and farming-pastoral transitional region, shows great vulnerability to disturbances from cultivation activity. In this region, the conflict between cultivation activity and environmental protection has not attracted great importance until the implementation of China's Grain-for-Green Policy(CGGP) since2000. Here, using Landsat5 TM/Landsat7 ETM+ images from 1990, 2000, and 2010, we monitor the cultivation activity and land-use/cover changes(LUCC) resulting from cultivation activity in the MUSL region. Based on the data from images, we developed a series of databases of cultivated activity-induced LUCC and use them to discuss comparatively the spatio-temporal evolution trends of cultivation activity before and after CGGP implementation. These results provide evidence for managers to evaluate the implementation effectiveness of governmental policy and the influence of cultivation activity on the ecological environment of the MUSL region.

Prediction and Protection of Cultivated Land in China

[Objectives]To protect cultivated land and ensure national food security and to forecast the cultivated land area of China and the provinces(cities)in 2030,2035 and 2050.[Methods]Based on the cultivated land area data of the whole country and provinces(autonomous regions and municipalities)from 2009 to 2017,the OLS model is used to forecast the cultivated land area of China and the provinces(cities)in 2030,2035 and 2050.[Results]The results show that the predicted area of cultivated land in 2030,2035 and 2050 is 134.0886,133.7856 and 132.8764 million ha,respectively,showing an obvious decreasing trend.The national cultivated land scale predicted in this paper can meet the requirements of the 2030 national cultivated land retention target set in the National Land Planning Outline(2016-2030).However,in the total area of existing cultivated land,there is still a certain area of sloping cultivated land(accounting for about 4%of the total cultivated land area,it is appropriate to gradually return farmland to forest).At the same time,nearly 20%of the cultivated land has been polluted,and the low-quality cultivated land accounts for about 22%of the total cultivated land.[Conclusions]The situation of cultivated land protection in the whole country is not rosy.For this reason,some measures and suggestions are put forward:strengthening land consolidation,striving to improve the quality of cultivated land,and appropriately increasing new cultivated land;strengthening the protection of cultivated land resources and strictly controlling the reduction of cultivated land.

Design of Trinity Framework for Cultivated Land Protection

Starting with the goals and tasks of quantity,quality and ecological protection in different scales,this paper constructs a"trinity"framework of cultivated land protection system,and puts forward the key points of cultivated land protection in different scales.Finally,a preliminary evaluation is made on the quantity,quality and ecological protection of cultivated land on a macro scale in China.

Analysis on the Relationship between Ecological Protection Red Line and Red Lines of Other Elements

Ecological protection red line is the minimum spatial area and territorial boundary line to be protected to realize the unification of economic,social and ecological benefits by increasing the national and regional ecological capital stock,maintaining ecological security,improving people's livelihood,promoting the sustainable development of economy and society,and upgrading the function of natural ecosystem.There are connections and differences between ecological protection red line and the red lines of cultivated land,forestry ecology,water resources control and marine ecology.Essentially speaking,they are all to maintain national ecological security and social stability,and create a good living environment for the people.

Analysis of Temporal and Spatial Changes of Cultivated Land in Karst Areas of Southwest Guangxi Based on Landscape Pattern Indices

Affected by topographical conditions,the distribution of cultivated land in karst areas is relatively fragmented.More effective cultivated land protection measures can be taken in a targeted manner by grasping the spatial and temporal distribution characteristics of regional cultivated land.In this study,with the cultivated land of four county-level administrative regions(Debao County,Jingxi City,Daxin County,and Tiancheng County)in typical karst landform areas in southwestern Guangxi as the research object,combining with the spatial analysis function of the GIS software platform,the spatial distribution characteristics and temporal and spatial changes of cultivated land in the study area were investigated from 2009 to 2020 using the quantitative analysis method of landscape pattern indices,revealing the main problems of cultivated land utilization,and the multi-dimensional management ideas of cultivated land protection in karst areas under the background of rural revitalization strategy were proposed.

Early Warning of Cultivated Land Quality Based on Multiple Indicators

At present,the quality protection and early warning of cultivated land in China are actually based on the increase and decrease of the quantity of cultivated land and the change of its quality.The early warning of cultivated land quality based on this is easy to cause the problem of missing and wrong alarm.Based on the quality and productivity change of regional cultivated land,early warning on the regional cultivated land quality is conducted in this study respectively,and the results of the two early warning are compared.Moreover,a multi-indicator cultivated land quality early warning based on the quality change,productivity change and auxiliary indicators is proposed.The results show that:early warning of cultivated land quality based on quality and productivity change of cultivated land has certain limitations.Based on multi-indicator early warning,the number of counties with heavy,medium and light warnings in Henan Province is 52,8 and 11 respectively.The multi-indicator early warning result of cultivated land quality is more accurate,which can provide a basis for cultivated land protection and management assessment,and has great application value.

The Use of VHSR Imagery for Wildland Fire Prevention: Application to Land-Clearing Management in the South of France

Every year, the French Mediterranean area is subject to wildland fires. The prevention policy promotes the major role of forest layout, for which it is necessary to build appropriate facilities such as reducing ignition and fire propagation risks near the borders of roads and tracks, creating forest tracks to allow firefighters to move safely through the forest during a fire, creating fuel breaks in order to divide up forests and limit the propagation of fire. Land-clearing along a forest track consists in creating discontinuity between the herbaceous stratum and the tree stratum by eliminating the shrubby stratum and cutting tree crowns. It avoids fire propagation by convection, and enables firefighters to deal with the fire in safety. The main difficulty for forest officers is to identify an optimized method to select appropriate tracks to clear, because it is impossible to clear all the tracks each year. Remote sensing tools would seem to be particularly useful for obtaining the best strategic and economic overview of forest tracks at departmental scale. This theme “land-clearing evaluation method” was selected as a target application for the images derived from the new Pleiades sensors: products and services required by end users. The objective of this work is to assess the real potentiality of such Very High Spatial Resolution (VHSR) imagery for land-clearing management. The methodology used consists in image classification and spatial analysis in order to extract land-clearing quality, and also evaluation of land-clearing quality based on field questionnaires validated through interactions with firefighters and rangers. The development of this methodology and its application to QuickBird images-used as Pleiades data simulations-successfully showed that VHSR Imagery is useful for preventing fire risk. It seems to be a good perspective for providing operational mapping services to help land-clearing management.

我国保护性耕作的发展与政策建议

保护性耕作是一项可持续农业技术,以少免耕和作物残茬覆盖地表为主要特点,为我国农业生产带来了显著的经济、环境、社会效益;在我国农业生产转向大规模、高效率、智能化发展的背景下,推动保护性耕作的深化发展,有利于耕地保护、藏粮于地、藏粮于技等国家战略实施。本文从技术与机具研发、示范推广与能力建设、东北黑土区应用三方面,全面回顾了我国保护性耕作的发展历程;系统梳理了我国保护性耕作技术与机具的发展现状,涵盖代表性技术模式,地表秸秆及作物残茬处理、浅层土壤耕作、免少耕播种等关键机具;深入分析了适宜的模式与机具、法律和政策的支持、规模化种植大户的带动等影响我国保护性耕作发展的主要因素。研究建议,筹建国家级科技创新平台、整县推进高标准示范工程,加强政策引导、高质量实施国家级行动计划,持续开展保护性耕作技术宣传,以促进我国保护性耕作技术及应用的稳健发展。

未来30年中国耕地和高标准农田分布的省级预测

科学预测中国未来耕地和高标准农田分布对于保障我国粮食安全和提高耕地质量具有重要意义。该研究假设未来各省份耕地和高标准农田占全国总面积比例不变,根据各省份耕地和高标准农田实际面积、未来全国耕地及各省份高标准农田规划面积等数据,基于最小二乘法的二次多项式拟合预测未来30 a全国及各省份耕地面积和高标准农田面积,进而预测未来各省份耕地面积保有率和高标准农田占耕地比例。结果表明:(1)到2050年,我国耕地面积稳定在1.20×10^(8)hm^(2),耕地面积保有率稳定在100%,高标准农田面积达到1.03×10^(8)hm^(2),高标准农田占耕地比例从2020年的43.59%增长到2050年的85.89%,增长近一倍。(2)七大区域中,黄淮海区、长江中下游区、东南区的高标准农田占耕地比例较高,在2020年均已达到70%以上,东北区、西北区、青藏区、西南区高标准农田占耕地比例则处于40%~60%之间。到2050年,受耕地比例稳定中略有下降的趋势影响,黄淮海区、长江中下游区、东南区、青藏区高标准农田占耕地比例均达90%以上,东北区、西北区、西南区则处于70%~90%之间。(3)从各省份来看,江西省、浙江省、福建省、广东省等南方省份的高标准农田建设比例较高,而内蒙古自治区、黑龙江省、辽宁省、吉林省、山东省等北方省份的耕地面积保有率较高。研究得到的耕地面积及其保有率、高标准农田面积及其占耕地比例等指标的分省份预测值可以为未来相关部门制定国土空间规划等提供科学依据,也可以为未来耕地布局和农田利用等研究提供分省份的总量参考。

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。

东北地区耕地绿色利用效率测算及影响因素

推动东北地区耕地绿色利用是践行绿色发展理念、促进黑土地保护的重要途径。综合运用包含非期望产出的超效率SBM模型、Tobit模型对东北地区40个地级市2012~2021年耕地绿色利用效率的时空分布格局及影响因素进行定量测度。结果表明:①2012~2021年,东北地区整体耕地绿色利用效率较高,而东北各地区效率自2018年后开始呈现波动下降态势,2020年后有所回升;②东北地区耕地绿色利用效率空间差异性显著,分布格局随时间的推移而逐渐变化,在研究期内呈现出“东高西低”“四周高、中间低”“南北高、四周低”的演变特征;③粮食作物轮作面积比例、单位农作物播种面积农业机械总动力对东北各地区耕地绿色利用效率具有显著性负向影响,科技发展水平具有显著性正向影响,但是在不同地区,不同因素的影响强度存在一定差异。建议既要在政策制度上规范和引导,还应在技术上支持和赋能,通过实际措施提高东北地区耕地绿色利用效率,实现黑土地可持续利用。

闲置土地认定处置法律规则的优化研究

研究目的:优化闲置土地认定处置法律规则,以此推动闲置土地认定处置难的规范解决。研究方法:案例分析法和规范分析法。研究结果:(1)优化闲置土地认定处置法律规则是土地节约集约利用、闲置土地法制统一和闲置土地治理实践的共同要求。(2)认定规则粗疏和处置规则失当是闲置土地认定处置法律规则的关键缺失。(3)闲置土地认定处置法律规则的优化路径,一是要通过厘清认定标准的关键概念、明确认定标准的土地单位和完善认定标准的分类结构,弥补认定规则的粗疏;二是要通过设计协商处置的兜底规则和推动行政处置的过罚相当,匡正处置规则的失当。研究结论:优化闲置土地认定处置法律规则需以促进土地节约集约利用为目标,以科学性、公正性、融贯性和可及性为导向,并结合地方立法经验完善闲置土地的认定标准和处置方式。

Impact of farmer households＇ livelihood assets on their options of economic compensation patterns for cultivated land protection

With rapid urbanization and the socio-economic transformation, cultivated land protection has gradually become a major concern in China. The economic compensation plays a crucial role in promoting cultivated land protection and improving the utilization ratio of cultivated land. Farmer household＇s satisfaction has a great influence on the effectiveness of compensation. Therefore, households＇ willingness to select the economic compensation pattern for cultivated land protection has been considered and re-examined. By employing Participatory Rural Appraisal method （PRA）, 3 villages and 392 households were investigated and sampled in mesa and hilly areas of Chongqing. Then a quantitative analysis framework of household livelihood hexagon has been developed to quantify the livelihood assets of differ- ent farmer households. Finally, the Gray Relation Model and Probit Regression Model have been employed to explore the coupling relationship between the household livelihood assets and their compensation pattern options. The results show that there are both qualitative and spatial heterogeneity in household livelihood assets. We found that the inequality of livelihood assets is evident for five household types. There is a spatial trend that the higher the eleva- tion, the less livelihood assets are. In addition, their options of economic compensation pat- tern vary from Chengdu Pattern to Foshan Pattern due to their difference in livelihood assets and difference in location. In detail, there is a coupling relationship between household live- lihood assets and their compensation pattern; negative correlation is observed between natural assets value and household pattern options, while the other livelihood assets have positive impacts on compensation pattern in varying degrees, which from the top are psy- chological assets, human assets, physical assets, financial assets, and social assets respec- tively. A conceptual compensation pattern system has been designed to meet the demands for farmer households mainly according to their shortage in livelihood assets. In addition, compensation method, compensation standard, the basis of compensation and the source of compensation funds have been proposed accordingly.

基于土地利用现状的耕地种植属性空间分布特征研究

耕地是人类赖以生存的基本资源,耕地保护是事关国计民生的战略问题。为充分掌握耕地种植现状,及时为耕地保护提供数据参考,本文以寿光市为例,基于年度变更调查土地利用现状数据,采用核密度分析法、最近邻指数法、标准差椭圆法等方法对耕地进行统计分析,综合评估耕地及其种植属性空间分布特征,从而为后续耕地保护提供数据参考,进一步促进耕地资源可持续发展。

赣南低山丘陵区农业产业结构“非粮化”空间分异及其驱动力探测--以寻乌县为例

为刻画赣南低山丘陵区农业产业结构“非粮化”空间分布差异,严格落实耕地保护和科学管控“非粮化”,本研究以江西省寻乌县为例,采用地理探测器因子检测、交互作用检测等方法揭示赣南低山丘陵区农业产业结构“非粮化”空间分异特征及其成因。结果表明:2020年寻乌县农业产业结构“非粮化”水平为19.42%,以耕地转为林地和园地为主。农业产业结构“非粮化”空间分异与耕地本底条件、自然资源禀赋、经济区位、政策环境4个维度的因子均显著相关,而地形、农田基础设施条件、耕地连片度是农业产业结构“非粮化”空间分异的主导驱动因子。不同农业产业类型“非粮化”的关键驱动因子不同,多数因子对耕地发展林果业和设施农业的驱动方向相反,农业产业结构“非粮化”因子交互作用均为双因子增强或非线性增强。研究表明,赣南低山丘陵区农业产业结构“非粮化”空间分异明显,需要管控农业产业结构“非粮化”总量并客观分类处置,本研究为“非粮化”分类监测和客观处置提供了参考,为低山丘陵区优化农业资源要素配置和农业产业空间布局提出建议。

近十年我国耕地保护政策的回顾与启示

文章回顾了2012—2022年我国发布的耕地保护政策,采取政策量化分析和内容分析相结合的方法,从耕地数量变化、耕地质量建设和生态保护三个方面进行研究。结果显示,近十年我国耕地保护政策不断完善和细化,但政策手段使用并不均衡;全国耕地数量趋稳并逐步回升,但也面临耕地总体质量不高、耕地生态建设和治理体系不完善等问题。在下一阶段制定耕地保护政策时,应科学利用法律、行政、经济、技术政策手段,充分发挥各政策手段的优势,特别是针对耕地质量建设和生态保护等问题,进一步从经济运行层面探讨经济手段的使用,引导社会力量参与;同时还要关注耕地涉及的社会经济高质量发展下的耕地阈值、不同主体的需求问题,并建立健全政策体系和制度需求者的反馈机制。

耕地“进出平衡”政策执行的偏移风险、形成路径与规避体系研究

研究目的:以“内涵阐释—风险辨识—路径分析—规避体系”为逻辑主线,客观认识耕地“进出平衡”政策执行的偏移风险类型、风险来源与形成路径,探究耕地“进出平衡”政策执行偏移风险新命题,以期为提高新时期耕地用途管制政策的稳定性与连续性提供理论参考。研究方法:理论分析法和归纳演绎法。研究结果:(1)耕地“进出平衡”政策执行的偏移风险主要包括组织矛盾、保障滞后、利益冲突和监管缺失;(2)规划冲突与权责模糊、资金技术的双重约束、多元主体利益冲突以及对非耕行为的负激励程度不足是造成政策执行偏移的主要风险源;(3)“制度环境—利益互异—执行偏移”的逻辑主线,可解释耕地“进出平衡”政策偏移风险的形成路径;(4)规避耕地“进出平衡”政策执行偏移风险,需借助规划管理、资金技术、利益分配和科技预警等手段。研究结论:耕地“进出平衡”政策的执行,应重视政策演化不同阶段不同偏移风险的差异性,构建相应的风险规避体系。

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。