Grain security is a considerable challenge to the world in the 21 century, especially to China. The pattern of grain-output has changed greatly since the reform of the grain market, the accelerating urbanization and fast industrialization. In this paper, the model for the center of gravity of grain-output was built, and the change of grain-output pattern was analyzed from 1990 to 2005 with the model. The results showed that: 1) from 1990 to 1998, the grain-output center-of-gravity moved towards northeast at the speed of 7.6 km/year. In total, it moved 60.8km northward and 6.4km eastward; 2) In the period of 1998 to 2003, the grain-output center-of-gravity moved towards southwest at a speed of 16 km/year. Therefore, it moved 63.8km southward and 48.1km westward in all; 3) In the last period of 2003 to 2005, the grain-output center-of-gravity moved back to northeast at the speed odf 41.2 km/year. In other words, it moved 82.3 km northward and 46.8km eastward in all; 4) During the entire period of 1990 to 2005, the grain-output center-of-gravity moved remarkably from the south and east to the north and west of China, and the moving speed of grain-output center-of-gravity was increasing. Therefore, it can be summarized that the regional grain growth was unbalance, and the spatial patterns of the advantageous regions of grain-output were unstable. The driving mechanism for the changes of grain-output center-of-gravity was discussed from different aspects, including resources, economy, technology, and relative policies. Firstly, the movement of grain-output center-of-gravity was based on the spatial pattern of farmland and its changing tendency. Secondly, the key factor for the changes of grain output center-of-gravity is the development and utilization of groundwater in north China, while the direct cause for it is the adjustment of food consumption structure. Thirdly, the technology advancement, the imbalanced development of rural economy, and regional policies to support grain production are the driving forces for the movement of grain-output center-of-gravity since 1990. In the end, the effects of such change or movement were discussed. The changes of grain-output center-of-gravity have aggravated droughts in north China, reduced the agricultural land-use productivity, worsened the imbalance of regional economy, and altered the commercial flows of grain products.

通过构建粮食产量重心模型,定量分析了1990年～2005年中国粮食生产时空格局演进过程。结果表明：中国粮食产量重心呈现出“北上西进”的态势,粮食产量重心移动的速率不断增大,粮食产量增长的空间波动性逐渐增强,产量优势区的空间格局尚不稳定。从资源、经济、技术、政策等方面深入剖析了粮食产量重心移动的驱动机制。耕地资源的空间格局及其变动趋势是驱动粮食产量重心移动的客观基础,北方地下水资源开发利用是粮食产量重心移动的关键因素,食物消费结构变化是粮食产量重心移动的直接因素,科技进步、农村经济发展不平衡以及区域化的粮食支持政策是粮食产量重心移动的重要驱动力量。最后探讨了粮食产量重心移动的区域环境、经济及社会效应。

过去一个时期,在农业布局和农业区划的研究工作中,常常过多地强调对远景方案或建议的拟定,相对地忽视了对农业现状和发展条件的研究,从而工作成果总不免带有一些主观臆断成分,科学根据不足,实践意义和科学意义都很有限。

For the past 10 years, besides having made public quite many works dealing with regional agricultural geography and going on with agricultural resources survey and agricultwral region-alization, much has been done in an even more extensive scope including researches on land re-sources and land utilization and crop distribution. Among furthermore studies are the strategy of agricultural development and other relevant topics. 1. Compilation of the regional geographical series, a total of 22 monographs including the general volume and the separate volwme were published one after another. This series of works reflects systematically what has been achieved in the studies of agro-geography in this country. 2. Agricultural regionalization is one of research topics in the geographical sciences, more personnel have been sent successively into the giant task from nearly all of the geographical in-stitutions and the geographical departments in to the universities across the country and more pro-fessional papers and reports. More related professional papers pertinent to theories and methods in regionalization have come out in the geographical periodicals under the sponsorship of va-rious institutions. 3. Studies on the strategy of agricultural development. Quite a number of papers on agri-cultural development strategy have come out in the geographical journals. 4. Studies on the allocation of agricultural production. Geographers have played outstand-ing role for the government department in formulating long range planning and regulating argricultural production infrastructure. 5. Studies on land utilization. Summarized into the following three aspects: the drawing of 1:1 000 000 land utilization map; studies 0n the development, utilization and protection of land resources; studies on land resources and utilization in mountainous area.

近十余年来,中国农业地理与土地利用的研究主要在以下方面:农业地理丛书的编写,完成了中国农业地理总论和21部分省(自治区、直辖市)的农业区域地理著作;承担全国综合农业区划、自然区划、农业各部门与农业技术条件区划,进行了农业区划理论与方法的研究;对农业发展战略与我国人口、资源与环境的国情研究;为促进农业生产稳定发展,以因地制宜为原则进行农业各部门生产布局研究;1/100万土地利用图与土地资源开发、利用和保护的研究。上述研究是持续而广泛的,在理论上和实践上都取得了很大进展。

There has been less current literature on the pattern of Chinese agricultural geographic concentration and specialization. This paper discusses the geographic concentration pattern of China's planting in 2008. Through calculating the average Gini coefficient (0.46,0.66 and 0.68, respectively), the average Moran’s I index (0.11,0.18 and 0.20, respectively ) and the Location quotient (LQ ) in the three scale classifications at the provincial level, it is found that the planting in China presents certain geographic concentration and exposes different agglomeration degree at different levels of industrial classification. And the finer division of planting industry, the more obvious the trend of spatial concentration and specialization of production. At the macro-planting level, the distribution of crop production is relatively dispersed, while at the micro-planting level, the distribution of crop production shows the trend of more agglomeration and specialization. The regional specialized production pattern in Chinese planting has emerged. The regional specialized degree of the staple crops is low, and that of the commercial crops is relatively high. Although the specific pattern of spatial concentration is determined by the matching between the natural conditions and production conditions of various crops, the government decision-making, institutional changes and other social factors plays an important role in regional specialized production functioning as the optimization and adjustment to the natural gathering. So, by calculating the spatial autocorrelation and the Gini coefficient, specialized index in various types of crops grown in contiguous spatial patterns, the potential location of the agricultural regional specialization and large-scale production can be identified, which can help the government make specific agricultural policies in different regions.

The study aims to investigate the spatio-temporal changes in crop patterns in China since 1980. In doing so, the analysis methods of time-series trend and spatial cluster were used to cover the major eleven crops at county scale. The results indicate that (1) There are 16 kinds of crop combinations ranking in the China's top 10 during the past 30 years. Yet since 2002, the simplified cropping structure has been gradually replaced by the multiple cropping structure, which suggests an increase in the diversity index of crop patterns. In 1980, about 82.7% of China's counties have a similar crop pattern which is composed of rice, wheat, corn and their combinations, however, this pattern largely changed after 2002 due to the increase in the planting area of fruit and vegetables. (2) In the same period, rice planting area of 47% of the counties, wheat planting area of 61% of the counties of and corn area of 29.6% of the counties experience a significant decrease, while other crops show an increasing trend. As a result, rice-dominated cereal crops in China are slightly adjusted to the coexistence of rice, wheat and maize crops. In particular, maize area proportion shows a significant change, which forms a so-called "corn decreased belt” spanning from northeast to southwest of China. Urbanization had an important impact on crop patterns as fruit and vegetable planting areas rapidly grow so as to meet the increasing demands in urbanized areas. (3) Crop patterns also show an obvious spatial cluster effect in China's 1300 counties. The proportion of high cluster accounts for 2.86%, 5.64%, 6.11%, 4.53%, 1.62%, 7.77%, 8.24%, 12%, 10%, 1.41% and 9.35% of China's counties for rice, wheat, maize, soybean, fibers, cotton, vegetables, potatoes, fruits, sugars and oils, respectively. These crops are distributed in Northeast China, Xinjiang, Northern Shaanxi Plateau, Yunnan-Guizhou Plateau and the metropolis areas. This finding of this study can support the decision making in agricultural restructuring and adaptation to climate change.

综合运用时序变化趋势、空间集聚分析等方法,从种植结构类型和种植比例变化趋势分析了1980年以来中国县域种植结构的时空特征。结果表明：① 近30年来中国前10位的种植结构类型有16种,2002年后多元种植结构逐步替代单一型种植结构。粮食作物占优的单一种植结构类型呈逐年递减趋势,其中1980年全国82.7%的县级农业种植结构是水稻、小麦、玉米及其组合种植类型,2002年后的果蔬类型增加改变了种植结构格局。② 全国种植县中有47%的水稻、61%的小麦和29.6%的玉米的种植比例显著减少,其他作物呈现增加趋势。粮食作物由以水稻为主的格局调整为水稻、小麦和玉米共存格局,其中玉米种植面积比例在空间上变化最为显著,在中国形成北东—西南向的“玉米减少带”。种植结构调整热点的城市地区,城市化对种植结构变化影响显著,水果和蔬菜类种植比例在城市化地区快速增加。③ 种植结构变化趋势在1300个县形成空间集聚效应,水稻的高高聚集占全国县数的2.86%、小麦占5.64%、玉米占6.11%、大豆为4.53%、麻类为1.62%、棉花占7.77%、蔬菜占8.24%、薯类占12%、水果占10%、糖料占1.41%、油料占9.35%,主要分布于中国东北、新疆和沿海的城市化地区。

Based on Chongqing Municipality,a grain production and marketing balance area in China,we used statistical data and semi-structured interviews to study changes,reasons of crop farming and policy implications over the last 30 years （1978-2011）. The results indicate that during the last 30 years changes in crop farming were a kind of competitive situation with contraction of grain and expansion of vegetables and fruits;regional planting patterns changed from ‘dominated by grain’ to ‘give consideration to both grain and vegetables,fruits’;and crop farming realized efficiency. Changes in crop farming in Chongqing Municipality were a result of the combined action of various factors. For the whole process,the starting point of changes was from the liberation of farmer autonomy,the change condition was environmental change induced by all kinds of factors,and the basis of change was from different characteristics of crops. To ease the competitive situation,safeguard the self-sufficiency rate of grain,and improve the yield and quality of vegetables and fruits,methods include defining the redline of the grain sown area,shifting the planting patterns of grain,speeding up mechanization and installation,and the specialization of vegetables and fruits. To improve cultivated land use efficiency,based on Chongqing’s experience we suggest agricultural policies in grain production and marketing balance areas that transform the direction of agricultural policy from ‘One Focus’ （focusing on the grain production）to ‘Two Combinations’. One combination is the transfer of agricultural labor force and the capitalized agriculture of labor-saving,and the other is to maintain grain output stabilization and develop agricultural resource advantages and diversification.

在粮食连年增收的同时,粮食产销平衡区却成为中国粮食安全战略的软肋。本文以粮食产销平衡区重庆市为研究区,利用统计数据和半结构访谈信息,构建种植业变化影响因素灰色关联多维分析模型,研究了1978-2011年重庆市种植业的变化及其政策启示。结果表明,①1978-2011年重庆市种植业变化呈现粮食作物收缩、菜瓜果作物扩张的竞争态势,区域种植模式从“以粮为主”转变为“粮菜兼顾”,实现了转型增效;②重庆市种植业变化特征是各类因素综合作用的结果,是以农户经营自主权放开为起点、各类因素诱致的环境变化为条件、作物的不同特性为依据发展演化而致的;③划定粮食生产红线、转变粮食作物种植模式、加快菜瓜果作物生产机械化、设施化、专业化步伐,是重庆市缓解粮食作物与菜瓜果作物竞争态势,保障粮食自给率稳定和菜瓜果产量、品质持续提升的有效途径和办法。基于重庆的经验,研究认为,粮食产销平衡区的农业政策方向有必要从“一个专注”（专注于粮食生产）向“两个结合”过渡,将合理引导农业劳动力转移与推广节约劳动的资本化农业相结合、稳定粮食生产与促进农业资源优势发挥和多元化发展相结合作为着力点,推动耕地资源集约高效利用。

There have been few studies on the pattern of China's agricultural geographic concentration and mechanism of its evolution.Based on the calculation of barycenter coordinates,Gini coefficient,as well as spatial autocorrelation and specialization index of 12 crops in 1981-2008 in China,this paper analyses the spatial pattern and mechanism of agricultural agglomeration.It presents the following results.(1) Spatial concentration of China's planting gradually increased.At the same time regional specialization and regional diversification progressively strengthened.(2) China's planting transferred from the eastern provinces to the central and western provinces,for example,although the Sanjiang and Songnen plains were still important clustering areas,the significance of the former land of fish and rice gradually decreased.(3) Although the endowment of natural resources made the initial agricultural geographical pattern,the path creations caused by an accidental event or social variation revealed two important facts: opened the windows of local opportunity for the social agglomeration,and corrected and optimized the existing patterns of the natural agglomeration continuously.With the emergence of new enterprises or departments,the division of labor and their cooperation network arose,and the agricultural industrial clusters formed.If several paths were created simultaneously from different crops in different places,an organic and sustainable agricultural production system would form in the whole area.So,the evolution of agricultural geographic pattern experienced a process from the natural agglomeration to the social agglomeration with a perfect agricultural production system.In this process,the natural agglomeration plays a less important role than the social agglomeration.Technology and institution innovations would speed up the agricultural geographic concentration and spatial reconstruction.

Taking 17 types of crops in Henan Province as an example, this paper analyses the geographical agglomeration and specialized level of crops from 1989 to 2009. Based on evolutionary economic geography, an analytic framework of "Stability-Variation-Selection-Adaption" was established to explain the crops' spatial agglomeration and its evolutionary mechanism. The results indicate that agglomeration of crops is low and in slow growth, especially for the general crops; rice has the highest level of clustering, which has a great impact on the whole agglomeration level of crops. Levels of agglomeration and specialization of the economic crops are higher than the food crops, and their distribution patterns are relatively stable, still concentrated in the initially favorable areas. Specialized level of vegetable crops is low, and their spatial distributions are dependent on the urbanization level of each city. Fruit crops constantly concentrate in the western mountainous area of Henan Province, especially Sanmenxia City, and some fruit crops, such as grapes and peaches, appear to be in a decentralized trend. The municipal differentiation degree of crops is low, and the pattern of division and specialization has just emerged.

以河南省17 种农作物为对象,采用1989-2009 年的地市级数据,对农作物的集聚特点、专业化格局及其演化机制进行分析。研究结果表明:河南省农作物的集聚水平低且整体增长缓慢,尤其是遍在农作物;部分农作物有分散化的趋向,而水稻的集聚程度一直很高,较大程度上影响了河南省农作物整体的集聚水平;经济作物的集聚与区域专业化程度均高于粮食作物,且分布格局变化不大,仍集聚于研究时段初始时的优势区域;蔬菜类作物专业化程度较低,其空间分布与城市化水平高度相关,不断向郑汴地区集聚;水果类作物不断向豫西山地尤其是三门峡市集中,而部分水果类作物如葡萄、桃等则出现分散化的趋势。总体来说,各市域间农作物结构相似度高,分工与专业化生产初现雏形。在此基础上,构建了基于演化经济地理学的“稳定—变化—选择—适应”过程分析框架,对河南省农作物集聚与专业化格局的形成演化机制进行阐释。

It is of great significance to clarify the characteristics of temporal and spatial patterns of grain crops in china.Based on the agricultural data of Hebei province in the past 15 years (2001-2015), this paper uses the segment linear trend and the production index-output fluctuation coefficient to analyze the temporal and spatial characteristics of the main grain crops in Hebei Province, and food security in hebei province is evaluated.The results show that the trend of the main grain crop in Hebei Province has experienced two periods from fluctuation to steady growth in the past 15 years, and the trend of change is significant. From the point of view of the change of spatial pattern, the law of the gradual decline from south to north shows that the distribution of different crops is different; From the point of view of food security, the grain fluctuation coefficient of more than 70% in Hebei Province exceeded the national average level, the grain fluctuation coefficient was bigger and the food security risk was higher. However, from the perspective of per capital grain production, the safety level is relatively optimistic, food security situation is becoming stable. This study can provide the basis for the optimization of grain and material production in Hebei Province, the structural adjustment and the coordinated development of social economy.

阐述主要粮食作物的时空格局变化特征,对中国粮食安全决策意义重大。基于河北省县市近15 a (2001~2015年）的农业数据资料,采用分段线性趋势以及生产指标-产量波动系数来分析河北省主要粮食作物的时空变化特征,并对河北省粮食作物进行安全评价。结果表明：从产量与播种面积来看,近15 a河北省主要粮食作物变化趋势经历了由波动减少到稳步增长2个阶段,且变化趋势显著;从空间格局变化来看,大致呈由南向北逐渐递减的规律分布,其中不同农作物分布规律各有差异;从粮食安全方面来看,河北省70%以上年份粮食波动系数均超过中国粮食安全平均水平,粮食波动系数较高,粮食安全风险较大;但从人均粮食产量来看,安全程度相对比较乐观,粮食安全状况渐趋于平稳。研究可为河北省粮食生产时空布局的优化、结构调整与社会经济协调发展提供依据。

Central China, which consists of Shanxi, Henan, Anhui, Jiangxi, Hubei and Hunan provinces, is an important base for main food supply in China. After analyzing scale advantage, efficiency advantage, comprehensive comparative advantage and concentration ratio of grain production in Central China, this article further discusses countermeasures for the construction of grain production base in this region. First, it is found that, since 1978, rice and wheat in Central China have a stable comprative advantage while the corn and soybean do not. The comparative advantage index of rice production is above 1.10 per year and wheat production shows a steady rise, going from 1.00 in 1978 to 1.16 in 2012. The comparative advantage index of corn production is below 0.80 and soybean production presents a downward trend, going from 0.90 in 1978 to 0.80 in 2012. Second, seen from the horizontal perspective, the structure of comparative advantage of the four grain crops changes slightly. In 1978, the sequence of scale advantage is rice, soybean, wheat and corn, the sequence of efficiency advantage wheat, rice, corn and soybean, and the sequence of comparative advantage rice, wheat, soybean and corn. In 2012, the sequence of scale advantage is rice, wheat, soybean and corn, the sequence of efficiency advantage wheat, rice, soybean and corn, and the sequence of comparative advantage wheat, rice, soybean and corn. Third, the concentration ratios of grain production in eastern, western and northeast regions of China fluctuate whereas the concentration ratios of grain production in the central region keeps rising steadily. The concentration ratio of grain, rice, wheat and corn rose from 28.65%, 38.13%, 28.83% and 16.16% in 1978 to 30.08%, 39.87%, 42.40% and 17.16% in 2012 respectively. The statistics in 2012 shows that the concentration ratio of grain, rice, wheat ranked first among the four regions. Fourth, the analysis shows that grain production in the central region plays an increasing role in China. Therefore, from the perspective of grain safety in China, importance should be attached to grain production in Central China so as to remain firm in the status of the central region as a base for main food supply. And various measures should be taken to promote the stability and growth of grain production in Central China.

中部地区是中国重要的粮食主产基地,在分析中部地区粮食生产规模优势、效率优势、综合比较优势和集中度的基础上,进一步探讨了中部地区粮食生产基地建设对策。结论如下:① 1978 年以来,中部地区水稻和小麦具有稳定的比较优势,而玉米和大豆没有比较优势。其中水稻生产的综合优势指数均在1.10 以上;小麦综合优势表现为稳中有升,从1978 年为1.00 上升到2012 年为1.16;玉米的综合优势指数小于0.80;大豆的综合优势呈现下降趋势,从1978 年为0.90 下降到2012 年为0.80。② 整体从横向来看,水稻、小麦、玉米、大豆四大粮食作物的比较优势结构发生了变化。1978 年规模优势大小顺序为:水稻 > 大豆 > 小麦 > 玉米;效率优势为:小麦 > 水稻 > 玉米 > 大豆;综合优势为:水稻 > 小麦 > 大豆 > 玉米。2012 年规模优势为:水稻 > 小麦 > 大豆 > 玉米;效率优势为:小麦 > 水稻 > 大豆 > 玉米;综合优势为:小麦 > 水稻 > 大豆 > 玉米。③ 中国四大区域中的东部地区、西部地区和东北地区粮食生产的集中度均有波动,唯有中部地区的粮食集中度保持稳定上升,其粮食、水稻、小麦、玉米的集中度由1978 年的28.65%、38.13%、28.83%、16.16%分别上升到2012 年的30.08%、39.87%、42.40%、17.16%,2012 年中部地区粮食、水稻、小麦的集中度位于四大区域之首。④分析表明,中部地区粮食生产在全国的地位越来越重要,应采取各项措施促进中部地区粮食生产的稳定与增长。

Using GAEZ (Global Agro-Ecological Zones) model, the agro-climatic constraints, soil, topography and other factors were used to estimate maize production potential in Northeast China during 1961-2010, and the spatial and temporal patterns of maize production potential caused by climate change in this region in the past 50 years were analyzed. Results are shown as follows: (1) The average maize production potential had a larger fluctuation in Northeast China during 1961-2010. The maize production potential increased by 80.00 kg/hm2 per decade in Northeast China in the past 50 years; (2) Frequent changes of the maize production potential took place at the turn of the 20th century due to the changes in climate; (3) Heilongjiang province saw the highest total production potential of maize, namely, the increasing range of maize production potential was the highest, followed by Jilin province, and Liaoning province was the lowest in the past 50 years; (4) The production potential of maize fluctuated dramatically in Heilongjiang in the years of 1961-2010, while Jilin and Liaoning were in a relatively stable state; (5) In the past 50 years, maize suitable planting areas slightly increased in Northeast China, which was mostly found in the northwestern Heilongjiang. Meanwhile, the area with higher production potential increased significantly and showed the trend of northward movement. This study provides a theoretical basis for efficient utilization of climate and land resources and the optimization of maize production distribution.

利用GAEZ模型,综合考虑气象、土壤、地形等因素,估算1961-2010年东北玉米生产潜力,分析50年来气候变化导致的东北玉米生产潜力时空格局演变特征。研究发现：① 1961-2010年,东北玉米平均生产潜力波动较大,整体上以每10年80 kg/hm²的线性倾向率增加;② 由于气候变化,20世纪末、21世纪初玉米生产潜力变化较为频繁;③ 玉米生产潜力总值黑龙江省始终处于最高,近50年间增长幅度黑龙江省>吉林省>辽宁省;④ 近50年来,黑龙江省玉米生产潜力的波动较为剧烈,吉林省和辽宁省相对稳定;⑤ 近50年东北玉米适宜种植区有所增加,主要集中在黑龙江省西北地区,高生产潜力区域增加明显,呈现北移趋势。研究可为东北地区高效利用气候和土地资源,优化玉米生产布局提供依据。

Potential dynamics of agricultural crop sown area has attracted a wide range of attention from numerous researchers due to its ecological and socio-economic implications. This paper describes a method to develop and implement an integrated model to dynamically simulate future changes in sown areas of the world's major crops (rice, maize, wheat and soybean) at a global scale. The general hypothesis of this study is that crop sown area change is directly linked with farmer decisions on crop choice, and what kind of crop to be cultivated is highly dependent on the random utility of available crops. The modeling approach is based on a crop choice model, which is a Multinomial Logit Model and used to model farmer crop choice decisions among a variety of available alternatives by using an optimization approach. The assessment of model performance by comparing model estimates with FAO statistical data (2001-2003) and MODIS land cover product (2001) indicates its reliability and dignity for addressing the complicated dynamic change of agricultural land use change at present and capability for long-term scenario investigation and applications for the future. From model simulation for crop sown area change during 2005-2035 in different regions in the world, global potential cropping patterns of major crops can be interpreted. Moreover, the results present that the change rates and trajectories of crops in different regions show a great variation over time and space. This study is an attempt of detecting future sown area change at a global level by using a simplified approach along with some assumptions. Although some uncertainty remains in the model, the outcomes can help to understand and explain the causes, locations, consequences and trajectories of land-use change, and provide a great support service for land-use planning and policy-making activities.

The dynamic moving and spatial coupling of gravity center of county-level population distribution, economic development,and grain production in Henan Province has been researched in this article, and discussed the relationship between social development and above three factors based on the social theory, gravity center calculation and spatial coupling analysis model. The result showed that the spatial gravity centers of county-level economical development, population distribution and grain production have been moving in the north of geometric center of Henan Province. The consistency level changed sharply, and the spatial inconsistency pattern was very significant during the past 23 years. Before 2000, the spatial coupling level between county-level population distribution and grain production was high, and after 2000, the spatial coupling level changed among the gravity center of county-level economic development, population distribution and grain production. The gravity center of grain production and economic development moved oppositely in the southeast-northwest direction, and the influence of grain production to the gravity move of economic development has been decreasing, while the coupling level between the gravity centers of population distribution and economical development has been increasing during the same time. The social development in the eastern Henan shows a low-level spatial equilibrium with the coexistence of inversion phenomenon between grain production and government receipts and grain production and people’s livelihood. The social development level in rural counties obviously lags behind that in urban areas. The spatial pattern of social inequality at county level in Henan driven by the factors, such as regional economic development, social policies, spatial strategy, and path dependence, is tabbed the constitutive characteristic in the period of comprehensive socioeconomic transformation in China. Consequently, two steps on how to improve the county-level population distribution, economic development and grain production are proposed. On the one hand, based on the cognitive of China breadbasket, the farmland protection, technical support, policy tilt to grain yield should be forcefully developed to ensure the grain production scale in Henan and regional grain safe. On the another hand, some reasonable policies must be proposed to encourage the deep process of agricultural products and foster the development of township enterprise, to accept more surplus labor in rural society.

基于社会剥夺理论,利用重心计算及空间耦合分析模型,研究了1990~2013年河南省县域人口重心、经济重心、粮食生产重心动态迁移及其空间耦合,并探讨其与社会发展水平之间的关系。结果表明：23 a来河南省经济、人口及粮食生产重心均在省域几何重心北部变动,空间错位格局日趋显著,变动一致性波动剧烈;2000年前人口重心与粮食重心耦合度较高,2000年后粮食重心与经济重心明显呈东南-西北路径背向偏离,粮食生产对经济重心迁移的影响持续下降,而人口重心与经济重心耦合度逐步提升;传统农区社会发展严重滞后于经济增长水平,粮食主产县区的“粮食与民生倒挂”特征显著。

Theoretical framework on formation of specialized villages was proposed by using rational small household, division of labour and specialization and distance decay and neighbourhood affect theories. These theories from economics and geography determined the formation of specialized villages, but the types of the specialization are related to resources endeavor and environmental conditions of the villages. The paper illustrates the change of the economic structure of villages by applying mathematical models, stating that various geographical conditions surrounding a village leads to different marginal production efficiency, therefore forming specified production structure. If a village's environment proves suitable for certain production or service, then a relevant type of specialized village may emerge. Based on theoretical analysis, we use the census data of specialized villages in Henan Province in 2010, applying dummy variables representing 16 types of specialized villages, and selecting environmental variables such as landform, location, arable land area and labour force from a spatial database from government authorities. The regression results from the OLS models indicate a significant impact of village environmental conditions on village specialization: (1) more labour force leads to lower specialization; (2) abundant arable land benefits specialization; (3) the closer location to its county site results in higher probability of specialization on agricultural processing industry; (4) existence of a wholesale market may increase specialization on relevant villages, especially for agricultural processing and animal husbandry industries; (5) the villages located in hilly terrain show less probability on specialization than others, mainly caused by difficulties in transportation and shortage in arable land; while mountainous environment provides resources for the development of specialization. Results from qualitative models indicate diverse environmental impact in different types of specialized villages. Positive impacts of land availability are observed in tea plantation, tree nursery and fruit farm. Labour force assists the formation of labour intensive production such as floristry. Accessibility benefits specialization in fruit, vegetable production and floristry. Results of this study can be applied to policy making for guidance of specialization under various environmental conditions.

基于经济学和地理学中的“理性小农”、“劳动分工与专业化”和“距离衰减与邻里效应”理论,并考虑资源环境条件,建立了解释专业村形成机理和形成类型的理论框架。用数理方法推理了村产业结构的发展变化和专业村的形成。在理论分析的基础上,运用2010 年河南省的专业村数据,选择地形、区位、土地和劳动力等环境变量和16 类专业村的虚拟变量,使用最小二乘法进行回归,结果表明村环境资源条件对专业化率有显著影响:① 村劳动力资源越多,专业化率越低;② 村土地越多越利于专业化生产;③ 村离县级市距离越近,越有利于形成农产品加工专业村;④ 具有批发市场可以提高所有专业村的专业化率,对养殖业和加工业专业村更是如此;⑤如果其他环境相同,丘陵地区的专业化率比其他地区低;这主要与丘陵地区交通条件不畅、人均耕地较少等有关。采用定性模型分析表明:环境影响在不同类别的专业村有所不同。土地丰裕程度对茶叶、林业和水果种植等类专业村形成有正面影响,劳动力资源对花卉等专业村的形成产生影响;地域通达性对水果、蔬菜和花卉等时鲜产品专业村的形成产生正面影响。该研究结果的实践引申,在不同环境条件的地区,可以制定相应的适宜专业化发展的引导政策。

<b>【Objective】</b> To investigate the consistency of regional changes in China&apos;s vegetable production and its comparative advantages, and promote the distribution of vegetable production in the country from the perspective of adjusting comparative advantage. <b>【Method】</b> Based on the Chinese vegetable production data from 1990 to 2016, this paper systematically sorted out the regional changes of Chinese vegetable production, and used the comprehensive comparative advantage analysis method and the resource endowment coefficient analysis method to measure the regional comparative advantages. Furthermore, the panel regression was employed to analyze the impact of comparative advantages on the layout of vegetable production. <b>【Results】</b> The vegetable output of the top 10 provinces in China accounted for 70% of the total vegetable output in the country. The 10 provinces in the eastern region accounted for more than 40% of the total vegetable output in the country. The overall comprehensive comparative advantage index and resource endowment coefficient in the eastern region was greater than 1, the central region was less than or equal to 1, the northeast region was less than 1; the western region was equal to 1. For every 1% change in the comprehensive comparative advantage of each region, the sown area of vegetables in the whole country will change 0.8% in the same direction. <b>【Conclusion】</b> China&apos;s vegetable production concentration is high. The eastern region is China&apos;s main vegetable producing area, with comparative advantages in vegetable production, but its status is declining. The status of vegetable production in the Northeast has declined significantly in China, and its comparative advantage has also dropped significantly. Vegetable production in the western region has increased significantly in the country, and its comparative advantage has risen simultaneously. Comparative advantage is an important factor influencing the layout of Chinese vegetable production.

【目的】分析中国蔬菜生产的区域变迁与其比较优势的一致性,从调整比较优势角度促进全国蔬菜生产合理布局。【方法】基于2000年到2016年中国蔬菜生产数据,系统分析中国蔬菜生产的区域变迁,利用综合比较优势分析法和资源禀赋系数分析法,测度中国蔬菜生产的区域比较优势,利用面板回归,分析比较优势对蔬菜生产布局的影响。【结果】中国蔬菜产量前10位的省份蔬菜产量占全国蔬菜总产量的70%,东部地区10个省市蔬菜产量占全国蔬菜总产量的40%以上。东部地区整体综合比较优势指数和资源禀赋系数大于1,中部地区小于或等于1,东北地区小于1;西部地区基本等于1。各地区综合比较优势每变化1%,会引起其蔬菜播种面积占全国比重同方向变化0.8%。【结论】中国蔬菜生产集中度较高;东部地区是中国蔬菜主产区,在蔬菜生产方面具有比较优势,但其主产区地位在不断下降;东北地区蔬菜生产在中国的地位明显下降,其比较优势也呈现同步明显下降;西部地区蔬菜生产在全国地位明显上升,其比较优势同步上升。比较优势是中国蔬菜生产布局的重要影响因素。