H. J. Laanbroek
Oct 1, 1990
Citations
8
Influential Citations
210
Citations
Quality indicators
Journal
Aquatic Botany
Abstract
Abstract Plant growth in waterlogged soils may be greatly affected by reduced minerals such as ammonium, manganous and ferrous ions, and sulphide. A more detailed description is given of the microbial and chemical processes that lead to reduced minerals, as well as of the micro-organisms involved. Reduction processes do not occur simultaneously, but consecutively according to a fixed sequence: oxygen, nitrate, manganese (IV) oxide, ferric oxide, sulphate and carbon dioxide. Special attention is paid to the microbial mechanisms of mutual exclusion of reduction processes. Re-oxidation of reduced minerals occurs at the oxic-anoxic interfaces in the flooded soil, i.e. at the oxidized upper layers of the soil and in the oxidized rhizosphere of waterlogged plants with aerenchyma. The micro-organisms involved in the oxidation processes with oxygen are mentioned in relation to their ecological niches. Leakage of oxygen by plants with aerenchyma may be a way to counteract the toxic effects of reduced minerals. The conclusion, however, is that hardly anything is known about the sequence of oxidation processes in the oxidized rhizosphere.