Characteristics And Influencing Factors Of Soil Trace Elements In Different Restoration Model Of Degraded Red Soil

Trace element are necessary for plant growth and development.Under the condition of soil nutrient loss,the chemical characteristics of trace element will change after vegetation restoration.Based on the field and laboratory experiments,the contents,forms and distribution characteristics of Soil Trace element in different vegetation restoration modes of degraded red soil were studied,and the effect of Trace element on the effectiveness of soil was analyzed The main conclusions are as follows:(1)The soil trace elements of severely degraded red soil after vegetation restoration in different patterns were all within the national average except for the iron slightly lower than the national average.The total content of manganese in the soil was significantly reduced by the artificial forest restoration model.(2)The forms of soil trace elements in different recovery models are mainly in residue state,and the proportion of strong organic state is also large.The recovery models of the three plantations are more conducive to the increase of copper content in water-soluble,exchangeable and weak organic state,while reducing the copper content in iron manganese bound state.The pure forest of slash pine has lower water-soluble state and higher carbonate bound state than other plantation models,but it is more favorable for the transformation from residue state to strong organic state.Compared with the natural recovery,the distribution of the form of the subway changed greatly,which showed the decrease of the residue state and the increase of the water soluble state,the weak organic state and the iron manganese oxide combined state.Compared with the plantation,the content of residual,strong organic and Fe Mn combined manganese was higher in the natural recovery control area,and the available state(water-soluble and exchangeable state)of Schima superba pure forest was the highest.The natural recovery control plot is beneficial to the transformation of residual zinc to strong organic zinc,but the available zinc content(water soluble and exchangeable)is not high.The pure forest of Pinus elliottii is beneficial to the activation of zinc form to available form.(3)The content of available copper and zinc in the soil was increased by the vegetation restoration model of plantation,and the content of available manganese in the soil was increased by the pure forest of Schima superba and the mixed forest of Pinus elliottii and Schima superba.(4)There is a significant correlation between the soil properties of vegetation restoration and available Cu,Fe,Zn,and litter properties are closely related to available Mn.The content of available copper is mainly affected by the content of soil N,and the content of available iron is mainly affected by the content of soil N,organic C and C:P.The effective zinc content is mainly affected by moisture content,p H,effective copper content and effective phosphorus content.The content of available manganese is mainly affected by N content,Fe content,P content and Mn content of litter.(5)The available iron,zinc and manganese are closely related to the available state,while the available copper and manganese are related to the potential use state.There is a significant correlation between weak organic copper and available copper in soil.There was a significant correlation between soluble iron and available iron.Water soluble,exchangeable and weak organic manganese are significantly correlated with soil available manganese.There was a significant correlation between exchangeable zinc and soil available zinc.