Document Type
Unpublished Paper
Publisher
Utah State University
Publication Date
12-2025
First Page
1
Last Page
7
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Abstract
The Utah Reusable Root Module (URRM) is a zero-discharge plant-growth system designed for microgravity. We evaluated its performance across four consecutive ground-based crop cycles with mizuna (Brassica rapa var. nipposinica), dwarf ‘Rejina Red’ tomato (Solanum lycopersicum), and ‘Outredgeous’ lettuce (Lactuca sativa). Five root modules (RMs) used distinct top-cover/containment designs with peatmoss medium. Growth conditions were 23–28 °C, 16/8 h photoperiod, PPFD ≈ 800 µmol m⁻² s⁻¹, RH ~ 50– 60%, and air velocity ~ 0.8 m s⁻¹. Redundant moisture sensing (upper CS650, lower TEROS ONE) enabled accurate water-use accounting; slopes between sensor-derived water use and pump-based input were ≈1 ± 0.10, indicating consistent monitoring. Across crops, total water use and WUE (dry mass per liter) were: Mizuna (17-day cycle: 38 L; 2.1 g L⁻¹) and Mizuna (22-day cycle: 35 L; 1.9 g L⁻¹), tomato (104-day cycle: 168 L; 2.2 g L⁻¹), and lettuce (28-day cycle:30 L; 2.4 g L⁻¹). Vinyl covers reduced water use by 11–38% relative to permeable designs while maintaining equal or higher WUE. Overall, the system demonstrated reliable multi-crop operation with rapid harvest-and-replant cycles, identified peak ET (≤3 L d⁻¹) as a key operational constraint for condensation-recovery capacity, and showed that low-permeability covers improve water-use efficiency without apparent trade-offs.
Recommended Citation
Garrido-Ruiz, Claudia; González-Teruel, Juan D.; Dixon, Chihiro; Schreck, Sarah; Bugbee, Bruce; and Jones, Scott B., "Ground-Based Evaluation of the Utah Reusable Root Module: Summary of Three Crop Cycles With Mizuna, Tomato, And Lettuce" (2025). NASA. Paper 7.
https://digitalcommons.usu.edu/cpl_nasa/7