Abstract:

Topsoil (0～15 cm) properties of seven typical land use types (secondary forest lands, economic forestlands, Chinese Fir plantations lands, nursery gardenlands, slope farm lands, deforestedlands and abandoned lands) were studied in the hilly area of central Hunan Province. Soil density, pH, organic carbon content, total nitrogen content, total phosphorus content, total potassium content, hydrolyzed nitrogen content, available phosphorus content and available potassium content were selected as soil quality indicators. The soil quality levels and the degradation extent were evaluated by the integrated soil quality index and soil degradation index. The results showed that different land use types displayed significant difference in the soil density and chemical properties in the top soil. The soil quality integrated indexes were ranked as follows: secondary forest lands (95.35%)＞economic forestlands (73.83%)＞deforestedlands (64.41%)＞Chinese Fir plantation lands (62.61%)＞abandoned lands (56.30%)＞slope farm lands (27.35%)＞nursery (4.84%), and the indices of soil degradation were ranked as follows: the secondary forest lands (0)＞the economic forestlands (-9.90%)＞the deforestedlands(-14.35%)＞the Chinese Fir plantation lands(-14.96%)＞the abandoned lands(-22.22%)＞the slope farm lands(-32.16%)＞nursery (-40.44%). The consistency of evaluation results of the integrated soil quality index and soil degradation index showed that both methods were efficient in evaluating the soil quality levels under different land use types.

Key words: land use types, soil properties, soil quality, soil degradation, central hilly area of Hunan Province