Biochar is the charcoal applied to the soil along with other amendments to enhance the fertility of the soils. Terra Preta is more than 5000 years practice in parts of Amazon basin until the Europeans arrived. Along with charcoal the rural trash consisting of pottery shards, fish bones, compost, etc. was added to the less fertile acidic soils to improve fertility of the soils. The biochar application is useful as a means of carbon sequestration and mitigating global warming issues too.
The value of charcoal was known to Indians and utilized as part of traditional and cultural practices for various purposes. The charcoal was never considered as a waste material. The crop residue burnt in the fields gets converted into charcoal and ash. In the process, the earth (soil) also gets burnt. This practice benefited the soils and farmers since ages (here no comparison with composting the biomass). The slash and burn in the margins of the forests or inside the forests is a very well known practice all over India (although it is no more sustainable because of huge population demands and costing the sustainability of forests). The charcoal, a byproduct of the traditional stoves is added to the farm yard manure / compost, which gets inoculated with the soil microbes, which was later transferred to the fields. The waste from the potters kiln a combination of charcoal, pottery shards and little ash was always a valuable source for improving the fertility of the soils. Although the addition of charcoal to the soils was existing as a practice, but it was not explicit, it remained as part of traditional best practices in India. As we explore more and more evidences are visible and proves that the Indian farmers were using charcoal since hundreds of years. Because of such good practices agricultural activity is still sustainable in many parts of India.
Publicly available: yes
Countries where available: Worldwide
Price range (USD): Free
Available online: yes