Design and Construction of an Automated Irrigation System for Simulating Saltwater Intrusion in a Tidal Freshwater Wetland
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Sea-level rise is expected to cause saltwater intrusion into tidal freshwater wetlands. The resulting changes in the soil environment would likely cause shifts in plant and microbial communities and alter ecosystem functions. To simulate saltwater intrusion, we constructed a solar-powered automated irrigation system. The system consisted of holding tanks that were filled with freshwater or artificial brackish water during high tide. During low tide, the water was gravity-fed through solenoid valves and metered out to each plot. This system was controlled by an open-source microcontroller platform and built from off-the-shelf electronics at a cost of $1800. Porewater salinity in near-surface soils of the plots receiving brackish water was increased from freshwater to oligohaline levels within one month of operation and was maintained throughout the first summer of operation. This porewater manipulation led to changes in the plant community and in exchanges of carbon dioxide and methane between the marsh and atmosphere. The system has proven to be a reliable way of manipulating wetland salinity for studying changes in the physicochemical environment. With modifications, it could be used to manipulate nutrient loads, hydrology, and sediment supply in other wetland systems.
KeywordsSea-level rise Tidal freshwater wetland Salinization Automated irrigation system Arduino Environmental manipulation
We thank Meredith Doswell, Joseph Morina, Ben Colteaux, Georgios Giannopoulos, Bonnie Brown, and Rima Franklin for helpful brainstorming discussions while designing the system and/or their assistance with data collection and lab analyses. We also thank members of HackRVA (Richmond, Virginia) for providing invaluable help building the irrigation system. We greatly appreciate the comments provided by the editors and reviewers, which greatly improved the quality of this manuscript. This research was supported by the National Science Foundation, primarily through DEB-1355059 with additional support from DEB-1458633.
- Ferrarezi RS, Dove SK, van Iersel MW (2015) An automated system for monitoring soil moisture and controlling irrigation using low-cost open-source microcontrollers. HortTechnology 25:110–118Google Scholar
- Taylor JH (1995) The effects of altered inundation and wrack deposition on nitrification, denitrification, and the standing stocks of NO3 − and NO2 −. East Carolina UniversityGoogle Scholar