Viability assessment for the use of floating treatment wetlands as alternative production and remediation systems for nursery and greenhouse operations

Abstract

Floating treatment wetlands (FTWs) are deployed in nursery and greenhouse water retention reservoirs to help manage and mitigate nutrient contaminants within irrigation return flow. One management issue for FTWs is the need for plant harvest to avoid releasing nutrients back into the water column when plant tissues begin to senesce. Some researchers recommend harvesting the entire plant to prevent nutrient release. Resale of plants harvested from FTWs is one possible use of this live biomass by the nursery and greenhouse industry. To determine if nursery and greenhouse operations could use FTWs to clean water and simultaneously produce saleable plants, the objectives of this study were to (1) quantify the survival and aesthetics of plants after transplant from a FTW and (2) compare the time to market between traditional (containerized) and FTW production systems. Overall, plants harvested from FTWs were resalable. Plants transplanted from FTWs had higher survival and aesthetic ratings (scale of 1–5, 5 = highest quality) when transplanted to containers (4.26) compared to directly into the ground (2.81). The growth of Panicum virgatum and Canna × generalis ‘Firebird’ in FTW systems was two weeks slower than that of plants grown in traditional production areas. Sustainability of FTW systems combined with the capacity to produce salable plants that will return a profit improves adoption feasibility for production horticulture.