Dynamics of cropland resources value in fragile ecological zones of the loess hilly-gully region: A case study of Shanghuang Experiment Area

The purpose of this paper was to reconstruct the value theory of cropland resources and to protect croplands, to deepen our understanding of the value of cropland resources. The paper used the Shanghuang Experimental Area as a case study of the loess hilly-gully region to analyze the value system of cropland resources and proposed an efficient estimation method. The evaluated value system included economic value, social insurance value and ecological service value. Based on the method, the paper quantitatively analyzed the economic value, social insurance value and ecological service value of cropland resources in Shanghuang Experiment Area for 1982, 2000 and 2010, respectively representing the periods of before governance, governance and Grain for Green. The results suggested that the total value of croplands was low in 1982, which was only 43 700 Yuan·hm^-2. During the periods of governance (1982 to 2000) and of Grain for Green (2001 to 2010), the value of cropland resources rapidly grew. It increased to 241 348 Yuan·hm^-2 during governance period and to 564 738 Yuan·hm^-2 during Grain for Green period. Economic value growth was the fastest during the whole study period, which was only 8 700 Yuan·hm^-2 in 1982, increased to 109 600 Yuan·hm^-2 2000 and to 218 600 Yuan·hm^-2 in 2010. The proportion of cropland economic value in 1982 was only 19.91%, which increased to 45.41% in 2000 and to 38.71% in 2010. Next was social insurance value, which was only 21 108 Yuan·hm^-2 in 1982 but increased to 83 656 Yuan·hm^-2 in 2000 and 249 956 Yuan·hm^-2 in 2010. Ecological service value continuously rose, rising from only 13 893 Yuan·hm^-2 in 1982 to 48 091 Yuan·hm^-2 in 2000 and 96 182 Yuan·hm^-2 in 2010. Difference factors were responsible for the changes in cropland resources value in different periods. From 1982 to 2000, scientific and technological factors played significantly influence on the changes in cropland value. From the year 2001 to 2010, policy factors significantly drove cropland value. In order to further promote the value of cropland resources, it was necessary to strengthen the implementation of the policies on returning farmland to woodland and grassland, improving the quality and cultivation intensity of croplands and taking measures for agricultural water-saving. This could improve cropland resources allocation level in the loess hilly-gully region.