DTPA Exchangeable Soil Fe,Mn,Cu and Zn Contents in Different Cultivation Management

The aim of this work was to investigate the influence of different management practices on soil DTPA-extractable Fe,Mn,Cu and Zn contents in the cultivated soils.Soils under greenhouse and open field cultivation were sampled from the fields in Shanghai,China,where organic farming had been conducted for three years or conventional faming had been carried out in the same area.The results showed that the contents of soil DTPA-extractable Fe,Mn,Cu and Zn under organic management system were much larger than those under conventional management system.While soil DTPA-extractable Mn,Cu and Zn contents at 0-20 cm depth in the open field under organic management strategy were higher than those of conventional management.On the contrary,soil DTPA-Fe contents followed the different trend.ANOVA revealed that cultivation and management had a significant impact on the contents of soil DTPA-extractable Fe,Mn,Cu and Zn,especially under greenhouse condition.We concluded that the distribution and characteristics of soil exchangeable bases were changed significantly under different cultivation and management.