Balancing green energy and materials recycling: woody biomass for combustion and green waste composting combined with compost for growing media?
We tackled the question on how the green waste compost industry can optimally apply the available biomass resources for producing both green energy by combustion of the woody fraction, and high quality composts as sources of carbon and nutrients. Compost trials with removal of woody biomass before or after composting were run at nine compost facilities during three seasons to include seasonal variability of the feedstock. In this paper we focus on the use of the composts in growing media. Removal of the woody fraction before or after composting did not affect plant-available nutrient concentrations in the compost, but had a small but significant effect on water and air volume in the compost. The composts with woody biomass removal after the composting process had significantly lower water volumes at -50 and -100 cm. For the composts based on material collected in spring, i.e., the compost with the highest organic matter content on a fresh weight basis, we additionally tested potential innovations in the composting process to create added-value composts for use in growing media. Sieving out the fine fraction rich in soil particles resulted in composts with significantly higher organic matter contents (both on dry and fresh matter basis) and higher moisture contents but we found no effect on the electrical conductivity nor on pH. The feasibility for optimizing green waste compost characteristics for use in growing media is discussed.
Vandecasteele, B., Boogaerts, C. and Vandaele, E. 2017. Balancing green energy and materials recycling: woody biomass for combustion and green waste composting combined with compost for growing media?. Acta Hort. (ISHS) 1168:143-148
woody biomass for bioenergy, combustion, biofuel, bioresources, energetic valorization of biomass, circular economy