Transformation of Fe, Mn, Co, and Ni compounds in humic podzols at different moisture

Incubation of humic podzol at soil moisture of 60 and 100% field capacity (FC) and after addition of peat and glucose increased the content of nickel and cobalt compounds in the water-soluble, exchangeable, organic matter-bound, and amorphous iron-bound fractions. At the same time, the content of elements bound to crystallized iron compounds decreased twofold and fourfold at 60 and 100% FC, respectively. The content of cobalt and nickel decreased in the residual fraction by 25 and 50%, respectively. The transformation of cobalt and nickel in soil is closely related to the transformation of iron and manganese compounds as well as to redox processes. The lowest pH and redox potential (RP) as well as the highest increase in the mobility of the elements was observed after soil incubation with glucose at 100% FC.