中文摘要：

农地集约度下降、季节性闲置和常年撂荒是农地边际化现象之一。即使在当前惠农政策背景下，我国中部丘陵山区依然大量存在这种农地边际化现象。经过理论分析与实证，其原因如下：1．在工业化城镇化进程中，由于农业劳动存在较高的机会成本，导致丘陵山区农民非农化现象突出，农地集约利用程度下降；2．丘陵山区农业生态条件较差，农地边际收益较低；3．国家惠农政策的激励作用在丘陵山区存在相对失灵；生态政策与农业政策的不协调，对农业生产存在负外部性，从而加剧了当地的农地边际化。解决丘陵山区农地边际化问题的途径在于农业技术和组织制度的创新，改善农业生产环境，发展合作经济组织和特色农业，提高农地的边际效益；国家农业政策要因地制宜，并与生态政策协调一致。

英文摘要：

In the hilly-mountainous area in central China,agricultural land intensity is decreasing due to seasonal or all-year abandonment.This causes marginalization of agricultural land despite farmer-benefiting policies.By theoretical and empirical analysis,some reasons are found out as follows： 1.During the industrialization and urbanization process,farmers benefit more from urban employment than staying in farming.2.The agricultural ecological environment of hilly-mountainous area is so bad that the farmland＇s marginal revenue decreases;3.The farmer-benefiting policies are not the intended incentives in the hilly-mountainous area;ecological policies does not accord with agricultural policy,which aggravates local marginalization of agricultural land. Marginalization of agricultural land is rational behavior by farmers,but the process is significant to national food security and ecological construction.Marginalization of agricultural land in the hilly-mountainous area is driven by the multiple factors.In order to solve the phenomenon we must commence from the nature,economy,policy and so on to improve the agricultural environment,innovate agricultural organization system and technology,transform traditional farming,develop modern highly-effective characteristic agriculture,and increase marginal revenue of the farmland. In the meantime,national agricultural incentive policy should accord with ecological protection policy.The governments should adopt different subsidy methods in different areas,that is to say,they should adopt more special subsidy policies in the hilly-mountainous area under fragile ecology conditions.