Variation of soil trace elements under peach trees with different planting ages in typical rocky desertification areas

In order to identify the variation of trace elements of peach orchard soil with different tree ages in typical rocky desertification areas, this work selected the peach trees with planting age of two years, ten years, and twenty years, five pieces each, as the study object. Compared with the abandoned agricultural land（zero year）, we analyzed the vibrations of the content of Fe, Cu, Mn, Zn, and B in the soils, and established the relationship between the content of available trace elements and their physicochemical properties. The results show that，(1) The total content of trace elements belong to a medium variation level except the total content of Fe. (2) The total contents of Fe, Cu, Zn and B increase when planting age reaches 2 a, but decrease between 2 a and 10 a(P<0.05). The total content of Fe decreases with growing ages (P<0.05),but the tendency of the rest trace elements is opposite between planting 10 year and 20 year(P<0.05). (3) The content of soil available Fe, Zn, and B increase between planting 0 year and 10 years (P<0.05),but decrease in 20 years. The content of soil available Mn is opposite, which keeps consistency with the total content of Mn. Thus, planting 10 year is a turning point. (4) Changes of the soil property for different planting ages of the fruit trees (the change of pH, organic matter, and total phosphorus) are the main internal reasons for that the available content of trace elements change with time and human activity, such as applying organic fertilizer, is the main external cause. So after planting 10 year, attention should be focused on the application of fertilizer of trace elements.