Tei Tei Taveuni regenerate island’s soils with locally produced biochar
Tei Tei Taveuni is an NGO formed by a group of farmers with an interest in sustainable farming, soil regeneration, food security, conservation and environmental awareness. They live and farm on the island of Taveuni, the third biggest island in Fiji.
The group was established in 2009 to tackle declining soil fertility, which poses a substantial threat to the productivity of their farms. Not only does the island receive 3-6 metres of rainfall a year, which washes vital nutrients out of their volcanic soil, it also has the highest rate of deforestation in Fiji. Unsustainable land use affects the production of taro, a root vegetable of which Taveuni produce a large part of the export share. Taro is also the main reason for increased deforestation.
In order to address soil degradation and an over reliance on chemical fertilisers, Tei Tei Taveuni (TTT) have run a number of successful projects to educate growers in soil health and sustainable farming.
Following a sequence of Soil Schools for farmers on the Island – facilitated by Organic Matter Foundation – TTT became an active part of the Soil Health Project funded by AusAid and implemented by the Australian Centre for International Agricultural Research (ACIAR), SPC MPI and the TTT. The project has carried out a number of trials with organic and inorganic fertilizers to improve soil health on the Island. A key part of the work has been trials with locally produced biochar.
A sustainable, local supply of feedstock to process into biochar was easily identified. The island suffers from an invasive weed called guava, a woody plant that grows underneath coconut palms – impacting land use and preventing the harvesting of coconuts. The thick, dense wood is often used for cooking and smoking as it burns slowly and at a high temperature. Due to the high rainfall woody spices grow fairly fast and other sources of wood are also readily available.
The trials with ACIAR called for Biochar produced under controlled circumstances and so AusAid provided funding to purchase a SuperChar 100 Mk II pyrolysis kiln. The kiln is operated and used by the TTT.
So far the SuperChar Mk II has achieved around 20 successful burns, producing good quality biochar. To familiarise themselves with the kiln, guava wood was used for the initial burns. Now, the TTT are producing biochar from the low density part of waste coconut palms.
Their first trial was carried out in the middle of 2013. Biochar was added to the soil and the trial area planted with the legume Mukuna for “priming”. The plot was then planted in taro in April 2014. Applications of 5, 10, 20 and 40 ton/ha is currently being tested.
A second trial commenced in July 2014. The charcoal for these trials needed to be produced from low density coconut wood, a waste product in a process of using the high density part for coco-veneer. The coco-veneer project is funded by the ACIAR, who are looking to turn waste coconut palms into a usable product, which can be sold to finance the replanting of coconut plantations.
TTT is committed to producing low cost, locally sourced soil amendments that suit their island’s soils. As such, the biochar they have produced is mixed with fishmeal, soft rock phosphate and compost for priming. Some samples have been made with seaweed, fish emulsion and cow manure before being added to the land. The biochar they produce complements other more rapidly decomposing forms of carbon in the soil and provides a more diverse environment for the soil’s microbiology.
The SuperChar Mk II kiln has worked well and the initial training course provided by Carbon Gold was a necessary start.
The temperature/data-logger has been instrumental in producing consistent biochar for the trials and has made the workings of the kiln much easier to understand and explain.
The outcomes of the trials will evidence the benefits of biochar to the soils of Taveuni, however the Tei Tei Taveuni are quite sure they are on the right track, viewing biochar as an integral component of soil health in the humid tropics. As they say, “Life is interesting”.
Find out more about Tei Tei Taveuni