Reductie veen-ontginning door productie veenvervanger middels recycling Champost

This report decribes experiments with anaerobic digestation of champost and organic rest products for re-use in mushroom casing. The digestates will reduce the emission of carbon dioxide by peat use for casing and will reduce the number of transport movements. Both reductions serve the mushroom sector. Wageningen UR Greenhouse Horticulture is measuring the quality aspects of the digestates with standard methods used in the potting soil industry such as texture, organic matter and nutrient and ash content. In this report a literature review and measurements of digestates and casings are combined. The literature review lists critical values for amongst others salt, water and air content. It is argued values per unit volume are more informative on water and air distribution than values per unit weight. Extract indicate nutrient levels but only deliver an indirect indication of how plants or mushrooms experience their environment. Measurements indicate it is necessary to wash digestates thoroughly to arrive at EC values <1.0 dS/m. Stability and phytotoxicity of the end products are positive. Using the properties in a model for mixing various materials together did not deliver positive results until late in this project part. A second project part has started.