Waste conversion by insects: validation of a new method for improved performance

The resulting fertilizer from this process, referred to as ‘frass’, is rich in plant nutrients but rather unstable, biologically and chemically.

In this project, funded by Kungl. Skogs- och Lantbruksakademiens (KSLA) and under the responsibility of Dr. Ivã Guidini Lopes, the novel methodology of “frass recirculation”, i.e. the transfer of fresh frass from one bioconversion process to a second bioconversion step will be tested and evaluated for its potential in increasing the quality of waste bioconversion as well as the quality of the resulting organic fertilizer (“recirculated frass”).

This will be tested considering a long-term experimental design, in which several steps of recirculation will take place and the quality of the fertilizers with distinct recirculation levels will be tested chemically, microbiologically and using plant models as well. This project is expected to contribute to two major knowledge gaps currently existing in the insect industry, namely the strong need for using commodities (e.g. soybean and wheat bran) as drying agents for wet substrates used to rear larvae, as well as the poor biological stability of frass, which requires further processing before it is safe for use in agriculture.