Reclaimed water irrigation system for enhancing soil microbiome activity and carbon sequestration
A controlled irrigation research platform that uses reclaimed (treated wastewater) water to stimulate soil microbiome diversity and increase soil organic carbon. The team offers collaborative validation using programmable reactors and crop trials, with expertise in water quality, soil science, and microbiome analysis.
Overview
This research platform investigates how reclaimed water—treated wastewater containing residual nutrients such as nitrogen and phosphorus—can be used to stimulate soil microbiome activity, improve microbial community diversity, and increase soil organic carbon. Prior field observations from plots irrigated with reclaimed water showed measurable changes in soil microbiome composition and elevated soil organic carbon in areas receiving the highest nitrogen loads. The offering centers on a set of programmable irrigation reactors designed for controlled, replicable hypothesis testing, enabling partners to validate the agronomic and environmental benefits of reclaimed water irrigation across different crops and soil amendments.
Technical specifications
Reactor infrastructure:
- Individual reactors measuring 6 feet by 3 feet with a 2-inch gravel drainage layer for water sample collection
- A 2-foot sandy loam soil column overlying the gravel
- Programmable pumps delivering irrigation from controlled water quality tanks, with a separate clean water tank for control reactors
- Side ports enabling soil sample collection at depths of 8 inches and 16 inches
Monitoring and analysis capabilities:
- Bi-weekly soil organic carbon and soil microbiome tracking
- Soil respiration assays combined with digital droplet PCR to quantify bacterial, archaeal, and fungal biomass
- Illumina sequencing targeting Bacteria 16S, Archaea 16S, and Fungi ITS for community structure profiling at experiment start and end
- Drain water quality monitoring to document plant and microbial uptake of nitrogen and phosphorus
Modeling and validation:
- HYDRUS 1D simulations validated against reactor data to accurately predict water movement through the soil profile
- Existing short-rotation coppice poplar plantings with capacity to test alternative crops and arbuscular mycorrhizal fungi amendments supplied by collaborators
Technology readiness level
The platform is at an advanced validation stage. Field-scale evidence already documents that reclaimed water irrigation influences soil microbiome composition and soil organic carbon. Controlled reactor infrastructure is operational, and HYDRUS 1D modeling has been benchmarked against physical reactor behavior. The next phase involves side-by-side comparisons of reclaimed water versus clean water irrigation across selected crops, with and without arbuscular mycorrhizal fungi additions, to quantify effects on soil carbon and microbiome diversity under partner-specified conditions.
About University of Washington
The University of Washington is a large public research university with campuses in Seattle, Bothell, and Tacoma, known for a broad portfolio from fundamental discovery to applied innovation. Industry partners engage through a South Lake Union research campus adjacent to a major life sciences district and through collaboration programs that place faculty and students alongside corporate R&D. The university’s integration with a major academic health system enables clinical translation and large-scale trials. Research is supported by competitive federal funding from NIH, NSF, DOE, and DoD. A dedicated technology transfer office manages IP, licensing, and startup incubation with prototyping resources.
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