Contents of Soil Second and Trace Element From Citrus Orchards in Demonstration Area of Environmental Immigrants of Northwest Guangxi

Research was made on some indices of soil in Northwest Guangxi.The soil indexes include soil organic matter,total Zn,Mn,Cu,Fe,Ca,Mg,available Zn,Cu,Fe,and exchangeable Ca,Mg,pH etc.Soil samples include 126 topsoils,which were collected in the citrus demonstration area of environmental immigrants.The status of second and trace element contents in the soil of citrus orchard were studied.The result showed that total Zn,Mn,Cu content was low,and total Ca,Mg content was seriously deficient,and however total Fe content was superfluous.Exchangeable meso Ca,Mg were seriously deficient,available Cu content was seriously deficient,available Zn content was deficient,however available Fe content was all higher.When soil pH was 3.75～4.65,very significant negative was found between the contents of available Fe and pH values in soil,however there no correlation between the contents of available Zn,Cu,Ca,Mg and pH values in soil.There were a very significant positive correlation between the contents of available Zn,Cu,Mg and soil organic matter of citrus orchard,which indicated that improving soil organic matter help to soil nutrients status.