Black Soldier Fly (Hermetia illucens) Frass on Sweet-Potato (Ipomea batatas) Slip Production with Aquaponics

Abstract

Nutrient supplementations are often added to aquaponic systems to optimize plant production, and black soldier fly larvae frass is a promising organic fertilizer. However, the mineral composition of the frass is substantially influenced by the initial substrate. In an 8-week study, sweetpotato slips were cultured at commercial stocking densities in an aquaponic system which received weekly additions of either BSFL frass made from high-nitrogen expired fish diets or low-nitrogen fruits/vegetables. The sweetpotato slips (≥8 nodes) were harvested weekly. Despite differences in the mineral composition between the frass types, the water quality as well as slip production/sugar content were unaffected by frass type. The results indicate that a wide array of substrates may be suitable for producing black soldier fly larvae frass as a fertilizer in aquaponic systems. Lastly, aquaponics is a viable system to commercially produce sweetpotato slips.

Impacts of black soldier fly, Hermetia illucens, larval frass on lettuce and arugula production

“…In sweet potato slips there were no differences in mineral composition of treatments pertaining to the two top dressing dosages of BSFL frass, including K, P, Cu, Mg, Ni, and Zn. Cu and Fe were highest in the control and Mn was highest in the BSFL frass treatments (Romano et al, 2023).…”

“…The greatest lettuce dry and wet weights were found in the raw manure treatments, though the frass treatments did achieve significantly greater lettuce wet and dry weights than plants grown on the undigested coffee husks (Putra et al, 2017). BSFL frass was applied as a top dressing in two treatments (333 g/m 2 and 667 g/ m 2 ) to sweet potato (Ipomoea batatas, L., Convolvulaceae) slips, produced similarities in length, number of nodes, stem diameter, and chlorophyll between the control and treatments (Romano et al, 2023).…”