Main progress and prospects of land productivity research in China.

Research on land productivity is elaborated systematically.Focusing on the meaning,impact factor,evaluation methods and main content of land productivity,the study makes a brief comment.With the development of society and economy,and application of mathematical models and 3S technology,land productivity has achieved a comprehensive meaning,and its evaluation goes through a series of processes,from qualitative methods to quantitative methods,and from assisting the choice of land use patterns,regionalization and planning to sustainable land use.The evaluation also progresses from emphasizing particularly on the exact definition of land productivity to material feedback on land system itself to different land use patterns.Since 1995 people have paid particular attention to the ability of self-renewal on land productivity,and the effect of external stress on it as well as the elastic limit to resists external stress on land.Finally,the study comments briefly and proposes future research directions for assessing the sustainable development of land productivity and enhancing the applied research on 3S technology.