大渡河上游河谷与半山区耕地利用集约度及影响因素的对比分析

集约度变化是土地利用变化研究的核心问题，而目前对西部地区耕地利用集约度特征及原因解释的研究较少。该文采取参与式农村评估法（participatory rural appraisal，PRA），以大渡河上游典型河谷与半山区为例，共调查农户357户，通过Tobit和OLS估计方法，定量对比分析了河谷与半山区耕地利用集约度及其影响因素。研究表明：河谷区和半山区在耕地利用集约度上存在显著差异。无论是资本集约度还是劳动集约度，河谷区均高于半山区。影响河谷与半山区耕地利用集约度差异的因素有承包耕地面积、人均实际耕地面积、家庭固定资产、离集镇的距离、二三产业收入、农业劳动力、年需换工数量、人情往来支出等。耕地资源禀赋和农业劳动力数量是导致集约度差异的关键因素，农业生产条件或环境和家庭收入水平对其有重要影响。

Comparative analysis on influencing factors of cultivated land use intensity in valley and middle mountain area of upper Dadu River watershed

Abstract: Changes in land use intensity are core academic issues in land-use change research. At present, empirical studies on features and driving forces on cultivated land use intensity in Western China are scarce. Besides, how to apply quantitative analysis methods to analyze the influencing factors on the cultivated land use intensity in depth also lack in the research. This paper analyzes differences of cultivated land use intensity based on the field surveys of 357 households in five villages from valley to the middle mountain area of Jinchuan County in the upper Dadu River watershed, by adopting the methods of participatory rural appraisal (PRA). This paper also qualitatively and quantitatively analyzes the factors influencing on the differences using Tobit model and Ordinary Least Squares (OLS) estimation method. The results show that: 1) There are statistically significant differences in cultivated land use intensity between the valley and the middle mountain area. Both capital intensity and labor intensity in valley are higher than that in middle mountain area. In capital intensity of land use, the inputs of seeds, fertilizer, pesticide, herbicide and other production in valley area are more than that in semi-mountain area. However, it shows the converse situation in mulch inputs. Labor intensity varies by different cropping system. From these three most important food crops cultivation in corn, wheat and potatoes, planting "Corn+Wheat" two crops in a year are common in valley area, while in semi-mountain area, there has a gradual transition from originally planting two crops a year of corn and wheat to one crop of corn merely. 2) By quantitative analysis of Tobit and OLS regression model, we obtain that influencing factors on differences of cultivated land use intensity including originally contracted arable land, real per capita arable area, the family of fixed assets, the distance away from the market, income from the secondary and tertiary industries, the total family labor force, agricultural labor force, the number of years au pair and social relations. In valley area, originally contracted arable land and income from the secondary and tertiary industries have the negative impact on cultivated land use intensity, while real per capita arable area, the family of fixed assets, the total family labor force, agricultural labor force and the number of year au pair have positive influence. In semi-mountain area, originally contracted arable land and the total family labor force have the positive impact on cultivated land use intensity. However, the family of fixed assets, the distance away from the market and social relations have the negative impact. 3) Cultivated land resource endowment and number of agricultural labor force are key factors to cause cultivated land use intensity differences. In addition, the conditions or environment for agricultural production and family income levels also have important impacts on cultivated land use intensity differences. Using the results as bases, this study proposes that the government should promote the land transfer orderly, support the agricultural labor force, such as increasing agricultural subsidies on labor-saving input, improving labors' education and health levels, and further improving the rural infrastructure to facilitate the local farmers, etc.