Factors Influencing Oxygen Consumption Rates in Flooded Soils1
- K. R. Reddy2,
- P. S. C. Rao3 and
- W. H. Patrick4
Thirty-seven surface soil samples varying in physico-chemical properties were incubated under reduced (anaerobic) conditions to study the factors influencing oxygen consumption rates. Oxygen consumption rates were measured after introduction of a known amount of oxygen into a reduced (anaerobic) soil system and following the disappearance of oxygen as a function of time.
The time dependence of oxygen consumption in all flooded soils could be described as a two-phase first order reaction process. Rapid oxygen consumption during Phase I was followed by relatively slower consumption during Phase II. The first-order rate coefficient (k1, hour−1) for Phase I was approximately the same for all 37 soils evaluated, whereas each soil was characterized by a different rate coefficient (k11, hour−1) for Phase II. The average value for k1 was 0.15 hour−1 (coefficient of variation = 20%) while the values of k11 ranged from 0.0027 to 0.054 hour−1. Step-wise regression analysis of the data showed that NaOAc-extractable Fe of a reduced soil was the single best predictor of k11 and also the fractional consumption associated with Phase I. Significant improvement in these regressions was obtained when total NH4-N content of the reduced soil, in addition to reducible Fe2+ was considered.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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