Greenhouse gas emissions from Terra Preta substrates in India

For all investigated concepts, the production and application of the Terra Preta Substrate (TPS) lead to negative emission results under the selected assumptions, resulting from an assumed carbon sequestration that exceeds the greenhouse gas emissions from the production of the TPS. Whereby, the concepts with advanced pyrolysis technology are the most advantageous due to the reduced CH4 emissions from pyrolysis.

Emissions of methane and nitrous oxide from composting and pyrolysis process are by far the most significant emission sources in the overall result. The result shows a high influence of carbon sequestration in the overall balance. The carbon introduced and permanently sequestered, mainly via the biochar, leads to high CO2 credits.

TPS production, including pyrolysis and composting processes, and the application to agricultural soils interact with the environment and climate system in multiple complex ways, this results in many uncertainties.

In order to reduce these ranges in the future and to further increase the robustness of the accounting results, measurements of actual emission values or sequestered carbon should be taken regularly during the further implementation and operation of the investigated technologies in India.