Chemically versus thermally processed brown shrimp shells or Chinese mitten crab as a source of chitin, nutrients or salts and as microbial stimulant in soilless strawberry cultivation

Brown shrimp ( Crangon crangon ) shells and Chinese mitten crab Eriocheir sinensis were chemically demineralized deproteinized (denoted as M1 to M4 for the M5 M7 crab), torrefied at 200 300 °C R200, R255, R300), compared with a commercially available chitin source reference chitin). Based on their chemical characteristics, selection of sources was tested N mineralization capacity. The release high treated crab, but not or without acid treatment, indicating that treatment higher resulted in low availability. Interaction nutrients leaching experiment limed peat three thermally two processed source. K concentrations leachate lower than during fertigation. Irreversible retention observed one shells, chitin. had significantly net P, Na Cl Three shell based materials (M4, R200 R300) greenhouse trial strawberry dose 2 g/L peat. A very positive significant effect Botrytis cinerea disease suppression leaves found chitin, unamended control. 3 linked an increase microbial biomass 24% 28% due decomposition 9–44% uptake plants. • Production method rather feedstock determines properties Shrimp by torrefaction contained amounts salts. Chitin total plant uptake. Higher rhizosphere sources. Chemically retained exposure fertigation solution.