菜篮子工程对南京市大棚扩张的影响

农业可持续发展和土地利用转型是学术研究的前沿,而中国的“菜篮子”工程可将两者联系起来实现可持续集约化的食物生产。该研究基于政策梳理、遥感数据解译和农户实地调查,选取南京市6个大棚主要种植区作为研究区域,采用Tobit模型定量分析“菜篮子”工程对南京市大棚扩张的影响,同时定性分析农业、农民、农地政策在推动农用地大棚化转型中的作用。结果表明:“菜篮子”工程有效地推动了郊区农业设施化进程,使南京市大棚面积从1995年的23.58 hm2增至2017年的10248.89 hm2;随着城市化进程加快,距建成区1 km缓冲区内耕地占比从1995年的37.96%降至2015年的11.34%,蔬菜产地不断远郊化,因此市场和交通等区位因素对大棚扩张有重要影响,经分析大棚面积发生改变的比例随着与菜市场和道路的距离的增大而变小;大棚面积变化具有区域差异,但政策依旧是影响各区大棚扩张的显著因素;大城市郊区农地大棚化转型是农业、农民、农地政策和“菜篮子”政策协同作用的结果。

Influence of Vegetable Basket Project on greenhouse expansion of Nanjing City, China

Abstract: Agriculture has great significance for the national food, resource, and ecological security, closely relating to the life stability and health of every resident. The cultivated land is constantly occupied by urban construction as the urbanization rapidly increases. The transfer of a large number of rural labor force and the change of food consumption structure have caused great challenge on the production and supply of vegetable food in China. The former Ministry of Agriculture has launched the Vegetable Basket Project in 1988, to solve the tight supply of agricultural and sideline products. A Vegetable Basket Project planning aims to transform and expand the vegetable greenhouse base, with emphasis on strong resistance to natural disasters, stable and high yield, further to realize the balance of seasonal production and perennial consumption of vegetables. In remote sensing interpretation of Nanjing City from 1995 to 2017, the cultivated farmlands were retreating from the urban areas, and the vegetable producing areas were shifting from the central to the outer suburbs, while the greenhouse areas were ever-increasing, as the main source of urban construction and expansion. It is necessary to evaluate the Vegetable Basket Policy on the specific change of greenhouse areas in rapid urbanization. In this study, a field survey of farmers and policy analysis were carried out in six main greenhouse planting areas (Pukou, Lishui, Gaochun, Jiangning, Qixia and Liuhe District) in Nanjing, China. A Tobit model was used to quantify the impact of Vegetable Basket Project on greenhouse expansion. The variables included policy factors (whether it was a vegetable production base and the distance from vegetable production base), location factors (the distance from the vegetable market and the distance from the nearest road) and terrain factor (the slope). The results showed that: 1) The Vegetable Basket Project was an important driving force of greenhouse expansion in Nanjing in recent 20 years, thereby to effectively promote the process of suburban agricultural facilities; 2) In the Vegetable Basket Policy, the most significant impact factor was the planning and construction of vegetable production base on the change of greenhouse areas; 3) The location factors, such as market and traffic, were important impacts on the area of suburban greenhouses. The change proportion of greenhouse areas decreased with the increase of the distance from the vegetable market and roads; 4) There was a regional difference in the change of greenhouse areas. Both market accessibility and traffic convenience played a positive role in the expansion of greenhouses in each district. The policy factors were dominated in the different changes in greenhouse areas. 5) In qualitative analysis, it was found that the Vegetable Basket Policy, together with agricultural, farmers'' and farmland policy, promoted the transformation of farmland greenhouses in the suburbs of big cities.