基于洛伦茨曲线和基尼系数的耕地质量空间差异程度分析——以忠县耕地地力评价结果为例

Analysis of the Spatial Differences Cultivated Land Quality Based on Lorenz Curve and Gini Coefficient: A Case Study of Zhongxian County

耕地地力评价通过定量的方法对耕地进行分等定级,可以摸清耕地综合生产能力、土壤肥力状况及分布特征、土壤障碍因素,为政府和农业部门提供决策支持,对指导当地农业生产、保障粮食安全、促进农民增收有重要作用.耕地质量空间差异程度没有具体的量化指标,文章引入经济学中的洛伦茨曲线和基尼系数,对忠县耕地地力评价结果———各等级水田、旱地的质量差异程度进行定量分析,结果表明:忠县二等地、三等地的水田在各乡镇分布很均匀,一等地、四等地的水田在各乡镇间分布差异较大;忠县的四等地、三等地、二等地的旱地在忠县各乡镇分布较均匀,一等地、五等地的旱地在忠县各乡镇分布不均匀,过于集中于某些乡镇.该结果与当地实际情况基本相符,通过经济学简单的模型来分析耕地质量差异程度既简便又直观,为耕地地力评价结果的合理性判断、指导丘陵地区的耕地地力评价工作提供了一种新思路.

Soil productivity assessment as a quantitative method for classifying and grading the cultivated land can find out the comprehensive production capacity of cultivated land,soil fertility and its distribution,and soil obstacle factors.It is significant for decision-makers of governmental and agricultural agencies and for increasing local agricultural production and farmers＇ income.However,no specific index system is available for the analysis of the differences in the quality of cultivated land.This paper introduces Lorenz curve and Gini coefficient in economics to quantitatively analyze the differences in the quality of different classes of paddy fields and arid land in Zhongxian county of Chongqing.The results show that second-and third-class paddy fields are relatively evenly distributed in all villages and towns of the county,but its first-and fourth-class paddy fields show an inhomogeneous spatial distribution,and that fourth-,third-and second-class arid land is fairly evenly distributed in different villages and towns,but their first-and fifth-class arid land is heterogeneously distributed,being too concentrated in some towns.The above results of the study are in consistence with the actual local situation.It is thus concluded that analysis of the differences of cultivated land quality based on econometric models is a simple and intuitionistic approach and is worth extending in soil productivity assessment.