Environmental and Economic Potential of Using Co-Composted Biochar for Agriculture and Soil Remediation

Brett Nolan Gallagher

Master's thesis

Abstract:

Transitioning to agricultural systems less dependent on fossil fuels is necessary for sustainable production of food in the future. Free sources of organic materials are widely available and can be composted or turned into biochar to provide long term fertility and soil remediation. The experiment conducted was designed to test the limits of compost and biochar’s ability to remediate even the most polluted, lifeless soil. Co-composting small amounts of biochar (2-5%) sped up the composting process, reduced unwanted odors and gases, and appears to have a beneficial effect on plant growth and increased biomass. The addition of biochar had mixed results on the uptake of Pb, Zn, and Cd, however, the addition of compost always had a beneficial effect. Homemade green-waste compost outperformed commercially bought packaged compost in all comparisons. Additionally, a macro-economic discussion is made about the role of energy in agriculture using an “energy returned on energy invested” (EROI) framework. We conclude that the costs to people and the planet of a broken nutrient cycle is a root cause of ecological degradation. Fixing the nutrient cycle by properly composting organic matter mixed with biochar is a cost-effective solution to solving many of the world’s most pressing ecological and economic issues such as soil degradation, polluted water systems, and eutrophication. Going forward, a paradigm shift in social perspective is needed, from “dirt”, to a living, breathing soil that supports all life on earth.

Keywords

biochar, compost, energy, value, terra preta, risk elements, heavy metals, cycle

Language used: English

Date on which the thesis was submitted / produced: 16. 4. 2019

Thesis defence

• Supervisor: doc. Mgr. Lukáš Trakal, Ph.D.

Czech University of Life Sciences Prague

Faculty of Environmental Sciences

Master programme / field:
Geology / Environmental Geosciences