Coventry University (Innovation Fund)


September 2013 - present


Stockholm, Sweden: Biochar - for a Better City Ecosystem


Donna Udall

Project Objectives

Biochar is the product of thermal degradation of organic materials in the absence of air (pyrolysis), and is distinguished from charcoal by its use as a soil amendment (Lehmann and Joseph, 2009).  Its addition to soil, in which it can remain for thousands of years, means that it is currently viewed as a means of carbon sequestration (Laird, 2008). 

However, it also offers other benefits, including increased soil fertility, increased health and diversity of soil microbial populations critical to soil function and ecosystem services, and hence and improvement of soil structure, stability, nutrient cycling, aeration, water use efficiency and disease resistance (Lehmann et al. 2011).

However, research remains limited and results have been conflicting with more research being called for (Quilliam et al. 2012). With regard to crop yield, results have varied considerably and appear very much dependent upon experimental set-up, soil properties and conditions. This project seeks to address these gaps in an experiment involving participants across the UK with many different soil types.


How the BIOCHAR project will continue and the research impact it will create:

  1. Continuation of the 2014 biochar experiment assessing the impact on yield of biochar that has been in the ground for 12 months, by issuing new seeds and record sheets
  2. Launch new biochar experiment 2015 for growers and gardeners in conjunction with a similar initiative in Stockholm, Biochar – for a Better City Ecosystem.
  3. Conduct field trials to assess the impact on yield of biochar with farmers
  4. Set up mini steering committee (advice via phone and one on-site meeting) to advise on scope and methodology of experiment, ensuring compliance with regulation (EA) and organic standards (SA) and raise awareness of CAWRs work with these organisations
  5. Create track record for a bid currently being developed for Horizon 2020 – Biochar and Anaerobic Digestate, an Economic, Environmental and Social Assessment (BADEESA).

This work has acted as both pilot and inspiration for the PhD project of Donna Udall.  The title of her thesis is: Investigating the Impact of Biochar and Digestate on Soil Fertility and Arable Crop Yield. The aim is to assess the economic and environmental impact of biochar and digestate on a range of soils. This will encompass soil, crop quality and crop yield analysis in conventional systems. Objectives include pot, field and commercial scale trials to establish the impact of biochar and digestate, alone and, uniquely, in combination, on soil quality and crop yield and quality. The duration of the work is four years starting from 2016.

More details and instructions for the experiment (7MB download) | Experiment Results Record

For more information about this project please contact Donna Udall

Latest News

Is Biochar A Wonder Material? Only Farmer-Led Science Will Tell