四川盆地丘陵区农户行为对耕地质量的影响

农户行为是耕地质量变化的直接推动者，农户对不同质量耕地的响应直接影响耕地现实生产能力。该文采用BP神经网络模型对重庆市大足县耕地自然质量进行评价，发现研究区水田自然质量等级以二等地和三等地为主，旱地以一等地和二等地为主，耕地自然质量总体偏高；但耕地自然质量仅仅是耕地自然属性的反映，因此在基于对研究区农户行为调查的基础上，采用“影响力系数”对耕地自然质量进行修正，并将农户收益作为耕地质量货币化价值的表现，进一步讨论了耕地自然质量和农户投资结构对这种价值的影响以反映对耕地质量的影响。结果显示，耕地自然质量指数和农户收益间的数学关系以三项式模型、二项式模型等曲线方程模拟效果最佳，重庆市大足县大部分乡镇都是受到某单一投入因素的制约，通过分析弹性系数大小可以调整研究区农户投资结构。该文阐明耕地质量不仅仅取决于耕地自然属性，还受到农户行为诸如投入水平、管理方式、种植模式等因素的制约，因此，应进一步规范农户行为以提高耕地质量。

Effect of household behaviors on cultivated land quality in hilly areas of Sichuan basin, China

Household behaviors are the leading driving forces for the change of cultivated land quality, and their responses to cultivated land quality will affect the actual productivity. Cultivated land quality was assessed by BP neural network in Dazu County, Chongqing. The assessment results showed that paddy lands were mainly of the second-grade and third-grade, while dry lands were mainly of the first-grade and second-grade. It illustrated the high natural quality of the cultivated land, but the natural quality only reflected land natural characteristics. Therefore, influence coefficient was used to modify natural quality index based on the investigation to households. At the same time, by using the household income as the value of cultivated land, the impact of natural quality and investment structure on the value were further discussed. The results showed that trinomial equation and binomial equation were fitted to reflect the relationship between natural quality and income. In other words, household incomes were not only depended on natural attributes of cultivated land, but also affected by input and management. Because most of studied towns in Dazu County are restricted by one of investment factors, the elasticity coefficient can used to adjust the investment structure. The study shows that the cultivated land quality is not only determined by its natural properties, but also by investment, management, crop patterns and so on. Hence, measures should be taken to regulate the household behaviors in order to improve land quality.