| Soil magnetism measurement has been applied successfully in many fields of soil research.This method has many advantages,such as high sensitivity,low cost,convenience and no damage to the samples.This paper takes Pu’er Tea production base in Yunnan Xishuangbanna dadugang tea garden soil as the research object,choose different kind of tea planting age 5 block and control plots of a collection,each sample of three soil profiles,a total of 18,the profile depth is 120cm,the sampling interval is 20cm.Determination of k-T curves of samples of soil magnetic susceptibility,frequency dependent susceptibility χlfand χfd,saturation magnetization Ms,saturation intensity Mrs and saturation remanence coercivity He and remanence coercivity Her,hysteresis loop and representative sample,study various parameters data showed that the soil magnetic susceptibility in the range between 41m3/10-8kg-333m3/10-8kg rules the vertical profile changes with the increase of soil depth and decreases with the increase of soil depth increased first and then decreased,two kinds of law;tea garden soil magnetic susceptibility and χlf saturation magnetization Ms and saturation remanence intensity variation of Mrs three is similar to that of soil saturation coercivity He and remanence coercivity Her similar changes in.The following 60cm increased rapidly;samples with magnetite,the average particle size of magnetic minerals in a single domain,superparamagnetic larger magnetic particle content,containing a small amount can be transformed into strong magnetic minerals Material.The determination of heavy metal content in the sample,the content of heavy metals with depth curve and magnetic parameters associated with the analysis,the results show that:the vertical distribution characteristics of Cr,Pb and Hg contents are increased with the increase of soil depth,As and Cd were decreased and then increased;heavy metals pollution index were less than 1,with organic soil quality standards;Cr,As,Hg and Pb were significantly correlated or significantly correlated with Cr,As,X LF,Cd was significantly related,Hg was significantly correlated with He,Pb was not correlated with magnetic parameters,overall magnetic parameters and heavy metal content of good correlation is indicative of heavy metals.Determination of organic matter content in soil samples,bulk density and pH value,the results of correlation analysis,research and analysis of physicochemical properties of soil magnetic parameters show;organic matter and soil magnetic parameters were significantly correlated with soil pH value of magnetic parameters is not relevant,soil bulk density and magnetic parameters were significantly related.The reasons for the variation of soil magnetic parameters may be caused by vegetation types and planting patterns,which may be caused by organic matter content and soil bulk density. |
