Valorisation of by-products from agriculture and nature management: Opportunities for potting media, composting or as soil improver

Introduction
Nowadays, by-products and waste from the agricultural and fisheries sectors and the related processing industries usually have only low-value applications. Nevertheless, many of these fractions could be used in higher value applications. This would lead to more efficient use of the basic resources, waste reduction and better closure of cycles of resource use. The focus of one of the four research lines in the innovative GeNeSys project is to investigate the possibilities of valorisation through composting using a transdisciplinary research approach. In addition, the intense involvement of external stakeholders (farmers, horticulturists, scientists, policymakers, etc.) will ensure development of scientifically supported as well as socially acceptable solutions for valorizing agrofood and fisheries by-products. Composting can reuse part of the biomass to create and maintain fertile and healthy soil. But the diversity and availability of feedstock materials and the composting circumstances lead to differences in the quality of the compost. Many questions about the cost efficiency, logistic and institutional limitations still remain.

Objectives
The main goal of the research is the development of qualitative, economically feasible compost products with an added value for agriculture in Flanders. This development is based on an evaluation and innovation/product development part.

Evaluation study:
-What is the current situation of compost products in Flanders (production, process, effects, …) and what are the problems and opportunities?
-How can the supply of carbon-rich feedstock materials be assured? Is there a possibility to cooperate with the nature-management sector (grass/cane clippings, sludge from ponds, cut sods from heaths, …)?
-What are the opportunities and stumbling blocks when incorporating a fraction of animal manure?
-What are the opportunities and stumbling blocks for alternative additives and feedstock materials?

Research strategy
The first year is an explorative cycle, followed by a 2.5-year innovation/research cycle. In the explorative cycle, the by-products with the highest valorisation potential are selected based on scientific/technological and socio-economic criteria. The second (innovation-research) cycle elaborates the valorisation pathway of these by-products in more detail and prepares for market introduction. Intensive interaction with a network of stakeholders will be achieved. During the first year compost experiments with different (mixtures of) feedstock materials will be performed at the farm level and in industrial installations. Feedstock materials and composts will be sampled and analysed for chemical and physical characterisation. Weight determinations will allow for mass balance calculations. Later, during a field trial and/or pot experiment, the effect of the different composts on the soil and on the growth of crops will be assessed.