Evaluation of Continuous In Situ Monitoring of Soil Changes with Varying Flooding Regimes

Abstract

To support investigations of flood tolerance occurring at a field-based research facility, changes in soil volumetric water content, temperature, redox potential, dissolved oxygen content, and pH over the course of flood events were monitored. Electronic sensors connected to dataloggers for continuous monitoring of these parameters were installed, and soil redox potential and pH were also monitored manually for comparison. Soil volumetric water content showed that soils became saturated quickly following inundation. Soil redox potentials revealed a reduction of the soil with inundation; however, stagnant water treatments did not result in lower redox potentials than flowing water treatments. Similarly, dissolved oxygen content was not lower in the stagnant water treatment. The automated and manual systems detected similar trends in redox potential response to flooding; however, redox potentials measured manually were generally higher and significantly different from those obtained with the automated system. Anomalous readings were detected with the automated measurement of soil pH, indicating further need for improvement of this system.

Heterogeneous oxygenation of wetland soils with increasing inundation: Redox potential, water depth, and preferential flow paths

“…Studies of soil-zone oxidation-reduction (redox) potential almost invariably report reducing conditions beginning soon after inundation and continuing until soils once again become aerated (e.g. D'Amore, Stewart, & Huddleston, 2004;Dorau & Mansfeldt, 2016;Eshel & Banin, 2002;Fiedler, 2000;Mansfeldt, 2003;Moorberg, Vespraskas, & Niewoehner, 2018;Unger, Rose-Marie, Motavalli, & Kabrick, 2008). Exceptions have been reported only where water is advectively flowing through the soil zone, delivering oxygenated water faster than it is consumed by biological decay and respiration.…”

Redox potential (Eh) and pH as drivers of soil/plant/microorganism systems: a transdisciplinary overview pointing to integrative opportunities for agronomy

“…Literature on the subject is sometimes controversial, as shown by numerous reviews (Bartlett and James 1993;De Mars and Wassen 1999;Fiedler et al 2007;Gantimurov 1969;Greenland and Hayes 1981;Kaurichev and Orlov 1982;Kovda 1973;Rabenhorst et al 2009;Snakin et al 2001;Unger et al 2008;Zakharievsky 1967). These reviews reported two main problems: (i) the quality and the reliability of the equipment, especially for Eh, as different types of electrodes have been developed and as leaks or polarization of the electrodes can occur and distort the measurements; and (ii) the high spatial and temporal variability of soil Eh and pH, and consequently, the limited reliability of sampling and analysis methods, which needs to be carefully addressed.…”

Peatland porewater chemistry reveals field redox ranges for specific decomposition processes

“…Quantitative Eh-measurements were considered to be notoriously unreliable in uncontrolled environments (Appelo, C. A. J., & Postma, 2004; Unger et al, 2008). Fortunately, measuring and logging equipment has evolved and reliable stable continuous measurements in the eld are possible (Vorenhout et al, 2011) with Paleoterra redox probes (Vorenhout et al, 2011).…”