Fraction distribution of calcium in soils of different land use types in karst areas
[Objective]The effects of different land use types on soil calcium(Ca) fraction and the caused differences in pH and organic carbon were investigated, in order to provide reference for revealing influence of vegetation on Ca cycle in the karst ecosystem and using rationally land.[Method]The soil samples at the depth of 0-70 cm were collected from woodland, shrub, grassland and orchard.The characteristics of pH, organic carbon and Ca fractions in different depths of different land use type soils were analyzed.[Result]The results showed that pH, organic carbon and acid-soluble fraction, reducible fraction, oxidable fraction and residual fraction of Ca in the woodland were significantly higher than those of other three land use types.Furthermore, the Ca in four land use type soils was dominated by acid-soluble fraction, which accounted for above 50％ of total Ca, followed by reducible fraction accounting for more than 30％;the oxidable and residual fractions together accounted for 20％, and there was no significant difference between oxidable fraction and residual fraction.In addition, as for four land use types, all Ca fractions were extremely significantly positive correlated with pH (P＜ 0.01 ,the same below).And excepting residual fraction, three other fractions were extremely significantly positive correlated with organic carbon.[Conclusion]Different land use types significantly influence soil total Ca and its fraction distribution.Furthermore, the organic carbon content in woodland was higher than those in shrub, grassland and orchard, respectively, suggesting that woodland is more beneficial for accumulation of organic matter.
karst arealand use typessoil Ca fractiondistribution characteristic
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NSTL
万方数据
维普
