Research on Cultivated Land Carrying Capacity Based on Human-Grain Relationship in Hu′nan Province

With the view of human—grain relationship to estimate the land potential productivity and the study of cultivated land carrying capacity,it is great significance of the protection of national food security and regional sustainable development.This paper studied the situation of human—grain relationship of cultivated land in Hu′nan 2000—2008 by using the land carrying capacity model and land carrying capacity index.The results were as follows:(1) Under the present productivity level,Hu′nan Province could carry a population of 74.233 8 million and the index was 0.922,with a basic balance human—grain relationship.However,distribution of human—grain relationship was unever.Most parts of the south area were going to face an overload population;(2) before 2004,the areas of cultivated land carrying capacity were in a yearly declining trend in the north—central part,the west part and south part of Hu′nan Province,and then the areas were gradually increased;(3) according to the situation of human—grain relationship,the north—central part of Hu′nan Province was from the surplus state into a prosperous state,the west part of Hu′nan Province was always overload or on the verge of critical overload,the south Hu′nan Province was surplus.This study showed that the greatly regional differences of land carrying capacity in Hu′nan Province occurred,and the potential of population growth was limited,thus,we should strengthen the comprehensive improvement of land,improve the land production conditions,and promote the level of agricultural science and technology to achieve the sustainable development of regional resources,population and environment.