近年来北京市耕地多功能演变及其关联性

论文将北京市耕地作为一个整体，构建了北京市耕地多功能评价指标体系，基于2004-2011年统计数据，运用极差标准化法统一数据单位，分析了耕地多种功能的演变；运用改进的灰色T关联度分析了耕地各功能之间的关联性。结果表明：①2004-2011年北京市冬小麦、玉米和花卉生产功能显著增强，蔬菜和饲料生产功能显著减弱；生态环境功能用逆向指标表示且各指标变化不一，公路密度和农用塑料薄膜强度显著上升，农药强度波动下降，化肥强度波动上升。②耕地文化休闲功能显著增强；就业保障功能和生活保障功能显著减弱，粮食安全保障功能处于波动状态。③2004-2011年北京市耕地冬小麦生产功能和人均粮食保证率发展趋势最相近，其次为饲料生产功能与种植业从业人数比例。④农村劳动力机会成本越大，省工性作物可能具有更强的竞争力；耕地文化休闲功能和玉米生产功能越强，种植业从业人数比例越小；农民来自农业的收入比例越小，增产性投入越多。

Changes and Relationships of Arable Land Functions in Beijing in Recent Years

Based on establishing Beijing's evaluation system of arable land functions, this paper studies changes in arable land functions and discusses relationships between different functions with the range standardized method and the improved T correlation degree. Study data is mainly from Statistical Yearbook from 2004 to 2011. The results show that: 1) The functions of winter wheat, corn and flowers production of arable land are enhanced significantly, while vegetables and fodder production functions significantly decrease in Beijing from 2004 to 2011. The ecological environment function is expressed by reverse indexes which change differently, such as significant increase in road density and intensity of agricultural plastic film use, fluctuant decrease in pesticide intensity, and fluctuant rising in fertilizer intensity. 2) Leisure function is enhanced significantly. By contrast, employment safeguard function and life safeguard function are weakened evidently. Moreover, there is a fluctuation on food security function. 3) From 2004 to 2011, production function of winter wheat and the ratio of per capita grain guarantee have the similar trend, followed by fodder production function and the proportion of crop farming employees. 4) By the opportunity cost of rural labor increases, the labor saving crops may have stronger competitiveness. Similarly, the less the farmers'income from agriculture, the more the labor saving input. Besides, with the enhancement of the leisure function and corn production function, the proportion of crop farming employees decreases.