Reduction state and extractable compounds of Fe, Mn, and Al in flooded soils
1999
Dzhokova, M. | Kaloyanova, N. | Kostov, O. (Institut po Pochvoznanie i Agroekologiya "N. Pushkarov", Sofia (Bulgaria))
The dynamics of the reducing capacity (RC) illustrates the intensity of the reduction processes of soils dyring the flooding and they are related to the changes in pH. The results of RC are agreed with the results of nitrogen fixing activity (NFA). The flooding causes the increases of the content of the water soluble compounds (Fes, Mns, and Als), possessing higher migration ability. After the drying of the flooded soils the content of the dithionite and oxalate extractable and iron crystalline forms decreases in all soils, with exception of the content of oxalate extractable (amorphous) form of Al (increasing in all soils after flooding) and of Fe (increasing in a soil with more intensive reduction processes). The decrease of most form content indicates that they are consumed during the reduction course. The reactants of the reduction processes in the cultivated soils are mainly iron compounds and in the paddy solis - mainly organic matter constituents, since iron compounds have already reacted.
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