[Effect of soil moisture and wetting-drying on Mn release in Ca(NO3)2-amended soils]

A study on the effects of two moisture levels (200 and 400 g.kg-1) and wetting-drying on the solubility of Mn in Ca(NO3)2-amended soils showed that water regime was a factor affecting Mn availability. Easily reducible Mn was transformed into soluble and exchangeable Mn, when soil water content was high. Salt had a definite effect on the transformation of easily reducible Mn. NO3- could decrease soil redox potential, and inhibit the transformation of easily reducible Mn. Wetting-drying significantly(alpha < 0.05) decreased the content of soil water-soluble and exchangeable Mn, while Ca(NO3)2 increased the insolubility of Mn, which might eventually lead to the deficiency of soil Mn.