Study On Economic And Environmental Effect Of Rice Cropping Systems And Its Optimal Spatial Layout

In recent years,China's agricultural industry has shifted into the stage of high-quality development.Rice is one of the major food crops in China.It is of great of importance for food security,household employment and income increase.In previous decades,major drivers for yield increase included increasing usage of commercial fertilizers and pesticides,which has greatly increased total food supply and ensured national food security.However,increase in rice yield through these intensive practices has showed a slow and weak trend.Moreover,it has led to an increase in the cost of rice production and aggravated the loss of production efficiency,resulting to resources wastes and environmental pollution.The dual goal of economic and environment should be considered in the rice production.Specifically,the economic goal is to ensure food security by increasing rice yield,and improve farmers' income by reducing agricultural chemicals inputs and increasing resource use efficiency.The environmental goal is to ensure the sustainability of rice production by reducing resource consumption and environmental burden.We construct a framework of “rice system selection-spatial layout-guidance strategy”,trying to answer the three key practical questions: “What to plant?” “Where is the plant?” “Who will plant?”,and three corresponding scientific questions:(1)What are the differences in economic and environmental effects between the three rice cropping systems?(2)How to optimize the spatial layout of the three rice cropping systems to achieve the dual goals of economy and environment?(3)What is the internal mechanism of farmers' adoption decision on rice cropping system? Through the optimization and adjustment of rice production system structure,this study explores the theoretical logic and practical path to achieve the dual goals of economy and environment in the rice production.According to the above research problems and objectives,this study employs econometric methods,combines the micro-survey data and macro-statistical data,and conducts a rigorous empirical analysis based on overcoming the potential endogenous problems of the model.The main conclusions are as follows:First,the analysis about the economic and environmental effects of rice cropping system selection shows that single rice,ratoon rice and double rice have its own advantages in terms of economic and environment,respectively.These differences provide an opportunity for the structure optimization of three rice cropping system to achieve the optimal economic performance and environmental performance.Specifically,single rice has obvious advantages in reducing the greenhouse gas emissions per hectare.Ratoon ricehas advantages in terms of net rice income and greenhouse gas emissions per ton rice produced.Double rice has advantages in terms of rice yield,but also caused a surge in greenhouse gas emissions per hectare and per ton rice produced.Second,the analysis about the changes in spatial layout of rice production shows that(1)The total sown area of rice in China has shown a downward trend from the time perspective,and the spatial layout of rice production shows a decrease in the south China and an increasing in the north China from the spatial perspective.(2)In addition to climate,land,labor and capital endowments are the key factors affecting the spatial layout of rice production;(3)Rice sown area in each province of China has a significant positive spatial spillover effect,indicating that a spatial agglomeration situation exists in rice production.Third,the analysis of spatial layout optimization with the dual goal of economic and environment shows that the spatial layout of current rice cropping systems in the study region needs to be optimized to varying degrees if other conditions remain unchanged.Specifically,the spatial layout of rice cropping system in the cultivated region for rice in northeast,north China basically remained unchanged.The cultivation region for rice in central China,southeast China and double-cropping rice in south China are the key adjustment areas.In the South China,the land area devoted to rice cultivation will decrease,and single rice is still the dominant rice system.In the central and south China,the system dominated by single and double rice was shifted into ratoon rice.Fourth,the analysis of farmers' adoption decision of rice cropping system from the perspective of factor flow shows that:(1)Land transfer has a significant positive impact on farmers' adoption decision on double rice,indicating that the promotion of double rice strongly depends on operational scale.The heterogeneity analysis shows that it is not necessarily possible to obtain scale economies through expanding the farm size,and decentralized land transfer will inhibit the realization of scale economy.The probability of adopting ratoon rice and double rice will be significantly increased by land integration to expand plot size and farm size.(2)Off-farm activities have a significant positive impact on farmers' adoption decision on single rice.This indicates that farmers with non-agricultural employment ability will allocate more labor to non-agricultural sectors,so as to adopt single rice with less labor input advantages.However,if farmers decide to inter-generational division of labor,they may tend to adopt ratoon rice.(3)Specialized agricultural service has a significant negative impact on farmers' adoption decision on single and double rice,but a large significant positive effect on ratoon rice is found.This shows that specialized agricultural service can effectively improve production performance,inducing farmers to adopt more intensive rice croppingsystems.However,too many field operation processes will lead to a sharp increase in transaction costs due to the limitation of division of labor.Therefore,specialized agricultural service does not necessarily induce farmers to adopt double rice.It is worth noting that terrain condition determines the suitability of mechanization operation and labor substitution.In plain areas,specialized agricultural service has a significant positive impact on the adoption of ratoon rice and double rice cropping system.In hill areas,specialized agricultural service has a significant positive impact on the adoption of ratoon rice,but has a significant negative impact on the adoption of double rice.According to the above results,this study concludes that(1)The innovation of rice cropping systems and the structural adjustment in rice production should be paid attention to meet the dual goal of economic and environment;(2)The linkage and interaction effect of regional rice production layout should be paid attention to,and market segmentation and trade barriers between different regions should be eliminate;(3)The spatial layout of rice production should be optimized through scientific planning based on the comparative advantages of every region;(4)Inducing farmer to adjust the rice cropping system through promoting the optimal allocation of input factors including land,labor and services.The innovations of this study are as follows.First,economic and environmental effects are included in the integrated analysis framework,which provides a new perspective for the spatial optimization layout of rice production.Second,ratoon rice is incorporated into rice cropping systems,which enhance the completeness of the research objects.Previous studies have generally considered single-and double-rice,they failed to take into account ratoon rice.Finally,this study considers the heterogeneity of land transfer and agricultural labor migration,which has not been fully concerned in previous studies.This study fully considers the economic scale on the plot level expressed by continuous land transfer and the integration of land parcels,and the effect of inter-generational division of labor.This study enriches the research associated to the influence of land and labor factors on farmer's selection of rice cropping system.Due to the constraint of data availability and data structure,the research also has some limitations.