Location: Aquatic Animal Health Research
Project Number: 6010-32000-028-004-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 1, 2021
End Date: Feb 28, 2025
Objective:
Evaluate edible purslane species for saline tolerance and growth rates in a marine aquaponic production system.
Approach:
Purslanes (Portulaca ssp.) are salt-tolerant edible plant species. Purslanes, while not a common green leafy vegetable, are increasing in popularity due to their nutritional value. Purslanes are beneficial due to their high phytonutrients and high omega-3 fatty acid contents. Purslanes are also increasingly sought after as ground cover horticultural plants due to their showy flowers, low fertilizer needs, and drought tolerance. Because of their high saline tolerance and low nutrient needs, purslanes could make an ideal species for marine aquaponics. Their high value as a green leafy vegetable could aid in the profitability of marine aquaponic fish production. Three purslane species will be evaluated for saline tolerance in hydroponic systems – Portulaca oleracea, Portulaca pilosa, and Portulaca umbraticola. Plants will be grown in a hydroponic environment with six levels of salt tolerance. Using ocean level salt levels as a baseline (1X), the following scale of salt concentration will be evaluated: 0, 0.125, 0.25, 0.5, 1.0, and 2.0 levels of sodium chloride. Plants will be grown for eight weeks with other nutrients supplemented with half strength Hoagland’s nutrient solution. Plants will be rated for general plant health at 2, 4, and 8 weeks after planting. Plant biomass will be collected 8 weeks after planting. Following optimization of growth conditions, a demonstration trial using conditioned culture water derived from systems rearing marine species (e.g, Florida pompano; Trachonitus carolinus) will be evaluated for plant and animal growth and performance at the USDA ARS Aquatic Animal Health Research Unit.
