Temporal and spatial variation of Cu,Zn,Mn and Fe content in soils with long term trace fertilizer application on the Loess Plateau

Based on the 19 years fix position experiment on microelement fertilizer application on the Loess Plateau,the distribution of trace elements on soil profile was studied in this paper.The result showed that the content of available trace element was increased in topsoil after 19-year application of microelement fertilizer,in which the content of available Cu and Zn was increased by more than 5 times and 3.58 times,respectively.In term of the spatial variation in the profile,the change tendency of available Cu of all treatments was unanimous,and the available Cu content under the topsoil was lower than that on the topsoil.The change tendency of available Zn showed a similar pattern to that of Cu.The highest content of Mn on soil profile was observed in the layer of 80cm, the content of available Mn in other layers were obviously lower than that in 80cm soil layer,indicating that eluviations and accumulation of available Mn occurred.The effect of microelement fertilize application on the content of available Fe was divergent.