Caracterização físico-química do frass de Gryllus assimilis (orthoptera: gryllidae) e sua aplicação como biofertilizante para cultivo de microverdes

Abstract

Frass is a valuable byproduct of insect farms. These excrements emerge as a promising source of plant nutrition; however, there is limited research on the use of fertilizers derived from cricket frass. In light of this, the present study aims to characterize the physicochemical properties of frass from the black cricket (Gryllus assimilis) and assess the potential use of frass as a biofertilizer in the cultivation of beet microgreens (Beta vulgaris). The physicochemical characterization of frass was carried out using specific protocols for the determination of pH, dry density, wet density, current moisture, electrical conductivity, nutrients (N, P, K, S, Na, Ca, and Li), and proteins. For the evaluation of frass as a biofertilizer, a completely randomized experimental design was employed, comprising four treatments (0, 10, 20, and 30% frass) with 15 repetitions each. Each experimental unit consisted of a gerbox with 50 glomerules each. The parameters assessed included germination time and percentage. In the physicochemical characterization, the pH was 6.7, and the wet density was 481 kg/m3. Nitrogen, phosphorus, and potassium levels exceeded the requirements for a product to be recommended as a biofertilizer. However, the results indicated a negative effect on the germination time and percentage of beet seeds exposed to all evaluated concentrations of frass. Thus, it is concluded that substrates enriched with cricket frass are not viable for microgreen production.