Biochar solutions for reducing pollution in the Netherlands Guido van Hofwegen, Joep A. van den Broek, Gertjan A. Becx, Ellis Hoffland, Oene Oenema

Overview of this presentation Two Projects: Assessment of the use of bio char as manure improver to reduce nitrogen pollution Exploring the possibilities of charring green wastes in NL

Charcoal as manure improver - Intro Relevance: Fast intensification of animal and arable sectors 2005: 11,5 mln pigs, 100 mln chicken, 1,5 mln dairy cows EU Nitrate Directive and Water Framework Directive

Charcoal as manure improver Research question: Can charcoal improve the nutrient retention of Dutch sandy soils prone to leaching which are heavily fertilized with pig manure?

What can we expect? Charcoal is reported to reduce N leaching by Physical and chemical binding of N (in several ways) Stabilizing SOM (hypothesizing) But: Nitrate concentrations increases(?) What will happen with P? (Dutch sandy soils are P- saturated, increased availability might lead to leaching) Increased bacterial activity might increase gaseous losses (N 2 O).

Methods & Planning Pot experiments with several sand, charcoal and manure mixtures, representing the Dutch situation Experiments will start in September

Upcoming issues Which charcoal to use? How should we treat it before use (milling / NHO 3 treatment)?

Exploring possibilities of charring biomaterials in the Netherlands Exploratory study: Exploring the possibilities of charring green wastes and other biomaterial for a) generating energy b) reducing the emissions of greenhouse gasses other than CO2

Expected results Household and other organic waste (1 Mt C) 0.1 C in compost tons C02 equivalent NOW `Char scenario’ 0.5 C in biochar tons CO 2 equivalent

Issues to be addressed Will it be cost effective? Is it possible to char ‘wet’ wastes? Will the charcoal be usable (heavy metal content / P content etcetera)?