Study on the transformation and iron provision mechanism of iron fertilizers in the calcareous soil

The iron transformation , their effects on soil factors and iron availability of compound iron fertilizer (CF,self-made iron fertilizer) and sulphate iron(FeSO4) in calcareous soil were investigated by using soil incubation method. The results indicated that compound iron fertilizer could improved the distribution in available iron forms, having more powerful ability in regulating soil factors. Treatment with CF contained strikingly more available iron than FeSO4. The results also pointed out that exchangeable iron, carbonate-bound iron and Mn-oxide-binding iron are the main provider of available iron in calcareous soil. In addition, soil organic matter and pH value related closely with the transformation of iron in calcareous soil.