Dilmah Tea started applying biochar – a nutrient rich soil enhancer which can also offset greenhouse emissions – to its plantations in 2010. Dilmah has also, started making its own biochar from waste tea generated during production processes. Dilmah produced biochar is currently being used and tested within the Kahawatte Tea Plantations. This project contributed significantly towards Dilmah’s carbon neutral project and helped the Dilmah headquarters in Peliyagoda Sri Lanka achieve carbon neutrality in 2017.
Biochar is a type of highly porous charcoal. It is produced by the process of pyrolysis which includes heating natural organic materials (such as plant matter) in a high temperature in a low-oxygen environment that prevents combustion. Biochar application can prevent soil nutrient leaching. This can reduce the amount of fertiliser needed and boost agricultural productivity. It can also significantly reduce groundwater pollution.
Biochar has the potential to vastly improve soil functions by: absorbing toxic substances, improving nutrient and water retention, reducing soil acidity, and increasing soil microbial population size and diversity. A one-time application of biochar can remain active in the soil for 100s of years and offset a significant proportion of green-house emissions. Practices similar-to biochar application can be traced back thousands of years to ancient Amazonian civilizations.
Studies have suggested that Biochar is able to sequester a significant amount of carbon dioxide from the environment and helps reduce the emission of non-CO2 greenhouse gases such as methane (CH4) and Nitrous Oxide (N2O).
The overall objective is to evaluate the effectiveness of biochar as a potential soil enhancer in tea cultivation and to hopefully aid in the reduction of harmful chemical fertilizer use and organically improve the quality of plants as well as surrounding ecosystems and environment both above and below ground.
Large scale applications were completed in several Dilmah plantations, which have yielded extremely positive results for productivity. The first site for the biochar application was at Rilhena Estate followed by Kahawatte Plantations, chosen for its different agronomic and climatic conditions.
At present, research is being conducted at the Endana estate. More specifically, this research conducted by Dilmah Conservation expects to evaluate the potential usage of biochar as a multi-beneficial soil amendment to be incorporated in tea fields to increase yield and quality of tea.