Washington, April 11 (IANS) Scientists have discovered an extraordinary source of some of the richest, most fertile soil in the world, often called ‘black gold’. They simply have to mix charcoal in the soil. And it can battle global warming as well by holding the carbon in the soil instead of letting it escape into the atmosphere, according to a new study.

The discovery goes back 1,500 years to the central Amazon basin where tribal people mixed their soil with charcoal derived from animal bone and tree bark.

This indigenous and “revolutionary” farming technique holds promise as a cheap, carbon-negative strategy to rein in world hunger and curb the emission of greenhouse gases by trapping them in the charcoal-laced soil.

“Charcoal fertilisation can permanently increase soil organic matter content and improve soil quality, persisting in soil for hundreds to thousands of years,” said Mingxin Guo of Delaware State University and co-author of the study.

The findings of the study were presented Thursday at the 235th national meeting of the American Chemical Society.

The earth’s soil is the largest terrestrial pool of carbon. But if a lot of chemical fertilisers are used, soil microbes will quickly decompose organic matter into carbon dioxide and release them into the atmosphere, leaving the soil nutrient-poor, Guo said.

He found that soils receiving charcoal from organic wastes were much looser, absorbed significantly more water and nutrients and produced higher crop biomass.

Soil deterioration from depletion of organic matter is an increasingly serious global problem that contributes to hunger and malnutrition. Often a result of unsustainable farming, overuse of chemical fertilisers and drought, the main weapons to combat the problem - compost, animal manure and crop debris - decompose rapidly.

Guo is “positive” that this ground breaking farming technique can help feed countries with poor soil quality. “We hope this technology will be extended worldwide.”