Ash Fix
Introduction
Manure and synthetic fertilisers applied to agricultural soils across the globe are a huge, and growing, source of potent greenhouse gases. Nitrous oxide forms about half of these emissions. It has now been found that biochar—charcoal used to treat soil—not only increases soil fertility and natural carbon storage capacity, but also drastically reduces nitrous oxide emission from the soil. Soil plots treated with biochar were found to emit 55 per cent less nitrous oxide than those that had not been treated. Apart from wood, biochar can be made out of anything from municipal waste to manure.
Source
Down to Earth May, 2013