The above is a video from re:char fellow Dr. N. Sai Bhaskar Reddy. He describes the video as follows:
This is an effort to discover the Terra Preta Signatures by observing several fields in parts of India in the last 5 months. I had the hypothesis that if terra preta soils happened in Amazon basin, there is no reason why other civilizations around the world have not discovered similar properties of charcoal and adopted. For photographs and notes please see http://e-terrapreta.blogspot.com/. Charcoal as a component for soil fertility improvement in agriculture production is a fact known to people from ancient civilizations. Improving the soil fertility by all means for food security was the major concern of farmers since several centuries. Farmers are more sensitive in this aspect, because farming is their livelihood.