Abstract

Organic waste generation in aquaculture worldwide requires circular economy approaches. The revalorization of wastes in the Chilean salmon industry could be a potential soil amendment. We investigated the thermo-drying process on salmon sludge, evaluating it as an alternative to reusing in horticulture. The chemical characterization of untreated sludge (wet sludges: WS) and dried sludges (DS) were evaluated with thermogravimetry, IR spectroscopy, and fluorescence. Additionally, the germination index of the DS was determined in L. sativa, R. sativus, and S. lycopersicum. The results show that DS reduces salinity, ammonium content, and pathogens compared to WS. During the thermic process, there were no significant decreases in organic matter, phosphorus, potassium, and humic and fulvic substances. The high salinity in DS inhibited seed germination. This research constituted a novel contribution to studying the DS as a strategy for horticultural production. In the same way, the drying technology for salmon sludge favored the management of wastes, contributing to the circular economy in both the agricultural and aquaculture sectors. However, we recommend considering that excessive incorporation of DS into germination substrates or direct application into the soil could affect the crop's performance due to its high salinity.