Effect of Redox Processes on Soil and Water Quality
Investigators (most current known information)
Redox potential was continuously measured and recorded over a whole year using a field station installed in a commercial sod-production operation at Kibbutz Givat-Brenner, Israel. Combination Pt electrodes were installed at depths of 7.5, 15, 30, 60 and 90 cm. Combination pH electrodes were installed at 40 cm depth. Potentials were continuously monitored and recorded. Temperature and water inputs (rain and irrigation) were recorded. Field measurements continued from the summer of 1999 to the summer of 2000. Soil and water samples were taken periodically and analyzed in the laboratory.
The site is characterized by a sandy-clayey soil. It has been irrigated with reclaimed wastewater for about 25 years, and used for lawn-production for the last 10 years. A permanently reduced layer (pe=0.3±3.0) was found at 15 cm depth. Higher and lower horizons were, on average, more oxidized. The pe variability at a given depth was caused by seasonal, soil and agrotechnical variations. It appears that the low redox potential at the 15 cm horizon was related to a combination of the irrigation regime, input of effluents, root activity and cultivation practices. Higher weighted average redox potential at deeper horizons (to 90 cm) was due to lower local concentrations of organic matter. At the shallow depth (7.5 cm), higher average redox potential was due to faster gas exchange with the atmosphere.
The study is continuing at other sites, having different soil conditions and cultivational histories. The effect of prolonged soil drying on the redox potential in situ is studied as well as the effects of water quality parameters (fresh vs. reclaimed wastewater).
The results of the study has established the feasibility of long-term, non-disturbing in situ measurement of the redox potential variations in field soils. Further study will contribute to the ability to manage soil redox under conditions of continued heavy loading of wastewater, as is anticipated in Israeli agriculture in view of the scarcity of freshwater.
Articles in Journals
Banin, A. and I. Negev. 2003. "Long-term redox potential regimes in sod-producing fields irrigated with reclaimed sewage effluent." (in preparation).
Lee, K., J. Wu, J.W. W. Stucki and A. Banin. 2002. "Mitigation of the effect of Fe oxidation state on potassium fixation in redox-treated ferruginous smectite using trimethylphenylammonium." (in preparation).
Eshel, G. and A. Banin. 2002. "Feasibility study of long-term continuous field measurement of soil redox potential." Commun. Soil Sc. Plant Anal. 33:695-709.
Huo, D., K. Lee, J. Wu, J.W. Stucki and A. Banin. 2002. "Effects of Fe oxidation state on selectivity for Ca2+, K+, Cu2+ and quaternary ammonium cations in ferruginous smectite and soil clays."
Stucki, J.W., K. Lee, L. Zhang R.A. Larson. 2002. "The effects of iron oxidation state on the surface and structural properties of smectites." Pure and Applied Chemistry 74:2079-2092.
Lee, K. and J.W. Stucki. 2001. "Effect of trimethylphenylammonium on potassium fixation in redox-treated ferruginous smectite." Annual meeting of The Clay Minerals Society, Abstracts:47.
Kocherginsky, N.M. and J.W. Stucki. 2001. "Investigation of water and ions transport through a supported clay membrane." Adv. Environ. Res. 5:197-201.