Distichlis palmeri: Perennial Grain Yields under Saline Paddy-style Cultivation of Grains on Seawater

Abstract

All our major grain crops are glycophytic grasses that require irrigation with quality water, annual tillage and reseeding of non-salinized soils. Farming of perennial halophytic crops has the potential to circumvent these restrictive issues. The present study reports perennial yields and proximate analysis of Distichlis palmeri grain. D. palmeri is a C4 dioecious halophytic grass endemic to the Sea of Cortez where native Cocopah gathered its 8 mm long grain as a wild harvest. We grew first generation D. palmer perennially over four consecutive crop years under experimental saline paddy-style conditions that reflect its natural tidal-flat habitat. Mean grain yield from our experimental system with a 1:3 male to female ratio was 176 g m -2 (SD = 28.2). Crude protein ranged from 7 -12.5% with a net energy between 60 -75%. Grain from Crop 2 germinated and grew under brackish conditions into fully flowering plants in two years. Our model in Tucson, Arizona demonstrates feasibility of developing paddy-style landscape based cropping systems for the domestication of D. palmeri as a perennial grain crop for human consumption. Cropping of D. palmeri may serve soil remediation and carbon sink functions for salinized soils and as a repurpose for saline waste water supplies.

Total Coliform and Generic E. coli Levels, and Salmonella Presence in Eight Experimental Aquaponics and Hydroponics Systems: A Brief Report Highlighting Exploratory Data

“…Despite the small sample size of the study reported here, the results are consistent with the findings of several past studies [32][33][34]. For example, a study that collected basil, lettuce, barramundi and water from 6 laboratory aquaponics-systems over 118 days failed to detect generic E. coli, E. coli O157:H7, or Salmonella in any of the samples [34].…”

“…This previous study, like the study reported here, found similar levels of coliforms (between 13 and 1820 CFU/100-g; calculated using data reported in the study; [34]). Also similar to the study reported here, a study that assessed microbial contamination on lettuce and water samples collected from two Puerto Rican hydroponic facilities failed to detect Salmonella [32]. Interestingly, the low levels of microbial contamination reported here and in previous aquaponics and hydroponics studies, contrasts to the substantially higher levels of microbial contamination reported by studies conducted in conventional production environments.…”

“…While this may suggest a lower likelihood of food safety hazards in aquaponic and hydroponic systems compared to conventional agriculture, additional studies are needed to directly compare food safety hazards in these to conventional environments. Despite this need for additional research, the results of this and other aquaponics/hydroponics food safety studies indicate that contamination in aquaponics/hydroponics systems occurs at low-levels [32][33][34], and that large sample sizes are needed in future observational studies to fully characterize pathogen prevalence in these systems.…”

“…Although relatively few studies have investigated the prevalence and distribution of food safety hazards in aquaponics systems, these systems are of increasing interest as a way to address food sustainability and security needs. Studies conducted in conventional and greenhouse production environments, and fish supply chains indicate that multiple pathways exist for the introduction of foodborne pathogens into hydroponic and aquaponic systems, including, but not limited to, fish feed, fish waste, the system's water, and the vegetable seeds [3,[23][24][25][26][27][28][29][30][31][32]. Due to the limited number of studies that investigated food safety hazards in aquaponics or hydroponics systems [27,[32][33][34][35], additional prevalence data are needed to fully characterize and manage food safety hazards associated with various aquaponics and hydroponics inputs.…”

“…Studies conducted in conventional and greenhouse production environments, and fish supply chains indicate that multiple pathways exist for the introduction of foodborne pathogens into hydroponic and aquaponic systems, including, but not limited to, fish feed, fish waste, the system's water, and the vegetable seeds [3,[23][24][25][26][27][28][29][30][31][32]. Due to the limited number of studies that investigated food safety hazards in aquaponics or hydroponics systems [27,[32][33][34][35], additional prevalence data are needed to fully characterize and manage food safety hazards associated with various aquaponics and hydroponics inputs. This need is particularly pressing, since the data that currently exist vary substantially between studies.…”