Organic Waste Conversion Into Innovative Fertilizers?.

Dr. Kor Zwart's Abstract

World-wide the demand for biomass will increase tremendously during the next decades. Demand for food, animal feed and biomass for the industrial processes are the driving factors in this process. Food and animal feed demand will rise in response to the increasing global population and its higher prosperity with more animal products in diets. Industrial use of biomass will increase in response to the rapidly developing bio-refinery activities and the increasing demand for biomass in renewable energy production. A higher biomass demand will lower the return of biomass to the soil, be it as raw crop residues or processed material. Most likely this will lead to a conflicting situation in which on the one hand soil fertility may decline with decreasing soil organic matter (SOM) contents, while on the other hand a higher soil productive capacity is required to support more biomass production. A lower return of biomass to the soil may further lead to undesired risks from e.g. higher water and wind-erosion.

Consequently, it is a prime challenge to develop biomass production systems which not only allow for a nearly complete removal of primary biomass from fields yet simultaneously support a sustained and sufficient level of good quality SOM. In order to guarantee the return of high quality organic matter to soils, we need innovations in the production of effective organic fertilizers. The characterization and tuning of such organic fertilizers and of the processes to produce them need to be developed. We may use existing soil science to provide the understanding and concepts that allow us to characterize such new organic fertilizers in terms of e.g. its labile - to - stabile fraction ratio, the C:N (and :P) ratio and the CEC. We will outline the requirements on the desired properties of such innovative organic fertilizers and possible processes to produce them. We will present information from the EU-FERTIPLUS project on the current amounts of organic residues available in the EU, agricultural, industrial and municipal, and trends therein. In addition we will discuss if composting and/or biochar production can  be used in production of the required innovative fertilizers or if alternative innovative production processes are required to produce better fertilizers.