This application aims at finding a solution to a problem that exists in greenhouse production. Greenhouses have long been considered to be closed systems with no leakage to the surrounding environment. However, it has been shown that plant protection products (PPP) are found in the environment outside the production. The handling of the residual plant materials generally needs to be improved and processes that break down PPP:s developed. This application aims to study how fly larval composting (FLC) can contribute to finding a solution to an industry-wide concern, but also to develop a better handling of the plant nutrient-containing residual streams. The project is divided into four focus areas. In Focus 1, the volume and properties of the residuals are mapped, to be evaluated in the FLC process in Focus 2. A mobile FLC plant is prepared and tested in Focus 3; and in Focus 4, fly larval composting of the residual streams are conducted at a greenhouse in the mobile FLC plant.