Field Trials

From the biochar vineyard trial in the Swiss Alps (2007) to a nine-system carbon farming experiment in subtropical Nepal, the institute's field trial programme spans nearly two decades, three continents, and crops ranging from pumpkin, chili, and banana to cocoa, coffee, and tobacco.

The Ithaka Institute's field trial programme is among the longest-running and most geographically diverse in biochar research. It began in 2007 with the field trial at the Mythopia vineyard in the Swiss Valais  and made it round the world by setting up experiments with farmers and/or providing characterized materials and/or designing concepts to other researchers. 

Nepal has been the institute's principal field research site since 2014. The introduction of the Kon-Tiki kiln gave Nepalese farmers access to self-produced biochar, enabling a series of 21 multi-crop field trials across the country (Schmidt et al. 2017) that demonstrated the concentrated root-zone application method across 13 crop species. Founding Ithaka Nepal, we continued with forest gardening and afforestation activities where biochar always played a decisive role. In 2023, the institute established the Carbon Farming Field Trial in Ratanpur — nine farming systems on 10 hectares under long-term comparison, globally unique in its systematic approach to evaluating carbon farming under subtropical conditions. The Nepal programme is operated in partnership with the Ithaka Institute Nepal, led by Bishnu Hari Pandit.

Bangladesh scaled the approach to community level. Through the BUNCH and BUNCH2Scale projects (2016–19), biochar-based fertiliser production was introduced to 80 villages, demonstrating the feasibility of decentralised organic nutrient cycling for improved household food production (Sarahadara et al. 2021).

Cuba provided a unique testing ground from 2017 onwards, combining the recycling of organic waste materials with food, feed, and bioenergy production in a country progressing toward fully organic agriculture. Research focused on biochar produced from the invasive species Dichrostachys cinerea (marabú), testing nutrient retention capacity and agronomic performance under tropical conditions (Bio-C project, funded by the Swiss National Fund).

Ghana and Indonesia hosted cocoa root-zone trials from 2020, adapting the concentrated application method to perennial tree crops using injection technology and, subsequently, lower-cost alternatives including boreholes and living mulch (Meyer zu Drewer et al. 2022).

Colombia and Timor-Leste tested biochar-based fertilisation in coffee production systems, addressing the specific challenges of implementing new methods where construction materials, technology, and transport logistics are severely constrained.

Brazil extended the programme to tobacco production, while Benin — through a GIZ project within the German Federal Ministry's "One World, No Hunger" initiative — focused on the introduction and adoption of biochar-based fertilisation in West African smallholder farming.

In Europe, the institute's contribution to field research extends beyond its own trials. The institute also produced characterised miscanthus biochar on Europe's first commercial pyrolysis unit (Pyreg 500, Swiss Biochar) that served as reference material for field and laboratory trials across European research groups — including the first medium-scale biochar persistence study under field conditions in Norway (Rasse et al. 2017, PLOS ONE), which used the C4 isotopic signature of miscanthus to trace biochar carbon fate in temperate soil.