多元经营主体融合下耕地集约利用的时空差异及其微观机理

Modern Agricultural Park，as the frontline of establishing a new type of system for intensive agricultural operations，plays a typical demonstration role in the period of transition from traditional to modern agriculture. The key to sustainable and healthy development of the Park is to vigorously support traditional agricultural business entities, while new and different types of agricultural business entities are fostered, the success of which depends largely on the intensive and efficient use of high-quality cultivated land under market allocation. Thus，this project aims to examine land use intensity differences of typical cropping systems among diversified agricultural business entities in the Modern Agricultural Park of JiangJin District, Chongqing. It also aims at exploring the spatial-temporal difference of cultivated land use intensity and its microscopic driving mechanism to seek an integrated development model of diversified agricultural business entities. Firstly, a database featuring land plots, industry, land use patterns, agricultural business entities and village is built by participatory rural appraisal method and "3S" technology, based on data of the sample village, typical agricultural business entities and their cultivated land plots. Secondly, behavioral differences of heterogeneous agricultural business entities in their cultivated land use and the change of trajectories are identified by spatial analysis and quantitative statistics, with plot-level intensive land use as the entry point. And then, an evaluation model of cultivated land use intensity at plot level and a system dynamics model for determining changes in cultivated land use intensity are established. Quantitative analysis of the spatial-temporal difference as well as the microscopic driving mechanism of cultivated land use intensity is made, with the combined pressure from land plot property, household resource endowment and regional environment in consideration. Research results are expected to provide a key basis for innovating the selection and cultivation mechanism of diversified agricultural business entities, and for relevant policy-making.

现代农业园区作为构建新型农业经营体系的前沿阵地，发挥着传统农业向现代农业转型的典型示范作用，其持续、健康发展的关键在于支持传统经营主体的同时，多元化培育新型经营主体，而主体的培育能否成功在很大程度上取决于优质耕地资源市场化配置下的高效集约利用。为此，本项目以多元经营主体融合的重庆市（江津）现代农业园区为样区，以样点村-典型主体-样地调查数据为基础，以地块尺度耕地集约利用为切入点，采用参与式农村评估法和“3S”技术建立地块-产业-模式-主体-村庄数据库，借助空间分析和计量统计法对异质性经营主体耕地利用行为差异及转变轨迹进行识别，并通过构建地块尺度耕地利用集约度评价模型、厘定耕地利用集约度变化的系统动力学模型，将多元主体行为置于地块属性、资源禀赋和区域环境等压力作用下来定量剖析耕地利用集约度的时空差异，阐明多元经营主体融合下耕地利用集约度变化的微观驱动机理，旨在探索多元经营主体的融合发展模式。

现代农业园区作为构建新型农业经营体系的前沿阵地，发挥着传统农业向现代农业转型的典型示范作用，其持续、健康发展的关键在于支持传统经营主体的同时，多元化培育新型经营主体，而主体的培育能否成功在很大程度上取决于优质耕地资源市场化配置下的高效集约利用。本项目以多元经营主体融合的重庆市（江津）现代农业园区为样区，通过空间叠加分析，查明土地流转发生区耕地数量、质量与分布特征，揭示了山区土地流转扩展特征；采用发展指数、加权Ripley's K函数、邻近性指数，剖析了2009-2017年各类农业经营主体的数质变化，识别出退出的新型经营主体和主体变更区，研究了经营主体时空演变及产业响应，阐明了土地流转发生区异质性农业经营主体的转变轨迹及耕地利用行为差异，结果表明：研究区形成了“农业企业+种植大户+养殖大户+农民专业合作社+家庭农场”多元主体融合发展格局，主体数量在连续6年的快速增长后正逐渐放缓，且五类经营主体间发展不平衡；退地的新型农业经营主体以农业企业和农民专业合作社为主，而专业大户没有发生退地现象，退地原因兼有主动退地与被动退地两种情况；多元化农业经营主体催生了类型多样化、规模差异化、空间邻近弱的“花-菜-果-粮-养-特色”产业新格局；采用经验公式和超越对数函数模型，研究了土地流转中不同经营主体耕地及其附属资源整合特征与效率，结果表明：新型经营主体在土地资源、设施资源、资金资源和生产要素资源的整合度显著高于传统农户，而土地流转后非农化纯农户和非农化兼业户侧重整合人力资本、金融资本和社会资本，而稳定型纯农户和稳定型兼业户侧重整合生产资本，稳定型弃农户整合方向不明显，且不同种植模式下地块尺度生产技术效率有显著差异；构建基于遗传算法投影寻踪的地块尺度耕地利用集约度评价模型，评价了蔬菜产业不同新型经营主体耕地利用集约度，结果表明：蔬菜产业耕地利用集约度的主体差异显著，而差异的原因在于耕地质量和经营主体资源禀赋与发展潜力的不同。