Abstract

The structural reform of the supply side of agriculture is aimed at guaranteeing the effective supply of agricultural products，promoting a sustained and rapid increase in farmers’incomes，and promoting the sustainable development of agriculture，and it has put forward the requirement for China’s agricultural development to take the road of agricultural modernization，which is“highly efficient in terms of output，safe in terms of products，resource-saving，and environmentally friendly”.However，for a long time to come，small and decentralized farmers will remain the mainstay of agricultural production in China.The small-scale，decentralized and backward characteristics of small farmers make it difficult for them to obtain economies of scale and do not match the requirements of agricultural modernization.Under the guidance of market demand and economic interests，China has formed a number of dominant agricultural production areas with high degree of specialization and distinct characteristics.Within the main production areas，the development mode of specialized villages，which takes the geographical agglomeration production of small-scale farmers as its manifestation，is an important innovation to reasonably connect small-scale farmers and modern agricultural development.Relying on the large-scale operation of village as a unit，i.e.agricultural industrial agglomeration mode，specialized villages have great development potential.On the basis of summarizing relevant theories and taking vegetable industry as an example，this study applies structural equation model，simultaneous equations system model，spatial econometric model，heterogeneous stochastic frontier function model，quantile regression model，threshold regression model and other methods to construct the evaluation framework of the formation and spillover effect of vegetable specialized villages，and their effects on the potential of rural economic development，agricultural production factor allocation and environmental sustainable development.This study is mainly composed of four parts：first，based on theories regarding industrial agglomeration，this paper constructs a theoretical framework for the formation and effect of specialized villages；second，this study investigates the formation and driving factors of specialized villages，including the historical evolution and current situation of vegetable production areas，hierarchical structure and driving factors of the formation of specialized villages；third，this paper studies the effects of specialized villages，focusing on the economic effects，agricultural production factor allocation effects and environmental effects，which are brought by the spillover mechanism of industrial agglomeration development model of specialized villages；fourth，the paper summarizes the main findings of the study，and explores the optimum path of healthy development of specialized villages and the possibility and direction of coordinated development between specialized villages.The main conclusions of this study are summarized as follows：

First，the theoretical analysis of the formation and effect of specialized villages shows that，by summarizing the neoclassical trade theory，agglomeration theory and other theories related to agglomeration，the formation mechanism of specialized villages can be classified into six categories：natural resources，human capital，technology reserve，standardized production，market demand and government support.Under the industrial agglomeration development mode of specialized villages，technology spillover，socialized services，infrastructure sharing and factor agglomeration will bring about spatial economies of scale，which further affect the economy of specialized villages，allocation efficiency of agricultural resources and sustainable environmental development.

Second，under the background of agricultural product circulation system reform，the spatial pattern of vegetable production in China is changing，which has formed a number of major production areas with high degree of specialization and distinct characteristics.In the interior of the producing area，there is a multi-level spatial structure，showing the spatial pattern of“clubs”and“joint development”of specialized villages in the main production counties.Among them，specialized villages are the most dynamic and potential basic units of the main production areas.

Third，the analysis on the formation mechanism of specialized villages shows that natural resources are the basis of the formation of specialized villages，human capital is the endogenous driving force for the formation of specialized villages，market demand and standardized production are the external requirements for the formation of specialized villages.However，at present，there are some problems in specialized villages in China，such as lack of natural resources，small scale and decentralization of farmer households，weak technical reserves，and unfavorable government support，which restrict the development of specialized villages.

Fourth，the analysis on the impact of specialized villages on rural economic development shows that the formation of specialized villages can promote the construction of local management system，production system and industrial system.At the same time，through technology spillover，socialized services，infrastructure sharing and factor agglomeration，specialized villages have formed a virtuous circle of increasing vegetable production，farmers’income and improving vegetable industry.In addition，there are spatial spillovers between villages，relying on the flow of information and other elements to influence each other’s development，but there are some characteristics such as lowering effects with the increase of distance.

Fifth，the results of the impact of specialized villages on the allocation of agricultural production factor show that，on the whole，the technology spillover of specialized villages and the sharing of socialized services are conducive to the improvement of technological efficiency within specialized villages，but the effect of social service organizations on improving quality and income is still inadequate.Furthermore，for differentiated production entities，the spillover mechanism also has varying effects，exhibiting the Matthew effect.In addition，when the agglomeration degree is too high，it will also bring a“crowding”effect.Therefore，instead of“quantity”，improving the“quality”of industrial agglomeration is the development trend of specialized villages.

Sixth，the study on the impact of specialized villages on environmental sustainability shows that with the improvement of industrial agglomeration in specialized villages，infrastructure sharing and factor agglomeration are conducive to improving agricultural carbon productivity.At the same time，drip irrigation technology is also an important technology that meets the dual purposes of increasing agricultural production and increasing farmers’income.However，the problems of insufficient technical reserve，weak awareness of ecological environment protection，lack of demonstration leadership，inadequate function of social service organization，inconsistent with the requirements of modern agricultural production，and inadequate government support restrict the development model of industrial agglomeration in specialized villages to give full play to both output and environmental potential.In addition，the Matthew effect and“crowding”effect in the development of agglomeration can’t be ignored.

Seventh，the analysis on the healthy and cooperative development potential of specialized villages shows that：it is necessary to continue to promote the construction of specialized villages and give full play to the advantages of industrial agglomeration；cultivate new agricultural business entities and leverage their demonstration and driving effects；improve the construction of social service system and pay attention to tilting towards small-scale farmers；strengthen infrastructure construction to ensure smooth production；strengthen government technology support and realize multi-subject cooperative development；promote the transformation and upgrading of industrial agglomeration，to improve competitiveness and increase farmers’income.For the coordinated development of inter-village，it is necessary to set up a model of specialized villages，which plays a leading role in demonstration；promote complementary，coordinated and cooperative development among specialized villages in different links of the industrial chain；strengthen exchanges and cooperation among local governments and build a market-oriented mechanism and interest compensation mechanism.

Keywords ：vegetable，specialized village，industry agglomeration，spillover effect