Slash-and-char is an alternative to

slash-and-burn Slash-and-burn agriculture is a form of shifting cultivation that involves the cutting and burning of plants in a forest or woodland to create a Field (agriculture), field called a swidden. The method begins by cutting down the trees and woody p ...

that has a lesser effect on the environment. It is the practice of

charring Charring is a chemical process of incomplete combustion of certain solids when subjected to high heat. Heat distillation removes water vapour and volatile organic compounds (syngas) from the matrix. The residual black carbon material is Char (chemi ...

the

biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

resulting from the slashing instead of burning it. Due to incomplete

combustion Combustion, or burning, is a high-temperature exothermic redox chemical reaction between a fuel (the reductant) and an oxidant, usually atmospheric oxygen, that produces oxidized, often gaseous products, in a mixture termed as smoke. Combustion ...

(

pyrolysis Pyrolysis is a process involving the Bond cleavage, separation of covalent bonds in organic matter by thermal decomposition within an Chemically inert, inert environment without oxygen. Etymology The word ''pyrolysis'' is coined from the Gree ...

) the resulting residue matter

charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ca ...

can be utilized as

biochar Biochar is a form of charcoal, sometimes modified, that is intended for organic use, as in soil. It is the lightweight black remnants remaining after the pyrolysis of biomass, consisting of carbon and ashes. Despite its name, biochar is steril ...

to improve the soil fertility. Meiler 5

In that context, charcoal can be made using numerous and varied methods. The simplest, used historically in charcoal production, involves burning a pile of biomass by lighting it on the top (known as "top down burn" or "conservation burn") or an earth cover on the pile of wood, with strategically placed vents. A more sophisticated modern method involves equipment that recuperates and processes strictly all exhaust gases into pyroligneous acid and

syngas Syngas, or synthesis gas, is a mixture of hydrogen and carbon monoxide in various ratios. The gas often contains some carbon dioxide and methane. It is principally used for producing ammonia or methanol. Syngas is combustible and can be used as ...

. Slash-and-char offers benefits to the environment when compared to slash-and-burn. It results in the creation of biochar, which can then be mixed with biomass such as

crop residue Crop residues are waste materials generated by agriculture. The two types are: * Field residues are materials left in an agricultural field or orchard after the crop has been harvested. These residues include stalks and stubble (stems), leav ...

food waste The causes of food going uneaten are numerous and occur throughout the food system, during food production, production, food processing, processing, Food distribution, distribution, Grocery store, retail and food service sales, and Social clas ...

, or

manure Manure is organic matter that is used as organic fertilizer in agriculture. Most manure consists of animal feces; other sources include compost and green manure. Manures contribute to the fertility of soil by adding organic matter and nut ...

and buried in the soil to bring about the formation of

terra preta ''Terra preta'' (, literally "black soil" in Portuguese language, Portuguese), also known as Amazonian dark earth or Indian black earth, is a type of very dark, fertile human impact on the environment, anthropogenic soil (anthrosol) found in the ...

. Terra preta is one of the richest soils on the planet – and the only one known to regenerate itself. It moreover sequesters considerable quantities of

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

safely and beneficially, as opposed to the adverse effects of the slash-and-burn. Switching to slash-and-char can sequester up to 50% of the carbon in a highly stable form.Lehmann – Biochar sequestration in terrestrial ecosystems,'' supra'' note 11 at 407 (“If this woody aboveground

were converted into biochar by means of simple kiln techniques and applied to soil, more than 50% of this C would be sequestered in a highly stable form.”) The nascent

carbon trading Carbon emission trading (also called carbon market, emission trading scheme (ETS) or cap and trade) is a type of emissions trading scheme designed for carbon dioxide (CO2) and other greenhouse gases (GHGs). A form of carbon pricing, its purpose ...

market that sponsors sequestration projects could therefore help supplement the farmers' income while supporting a decrease in the pace of

deforestation Deforestation or forest clearance is the removal and destruction of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. Ab ...

and the development of a more

sustainable agriculture Sustainable agriculture is agriculture, farming in sustainability, sustainable ways meeting society's present food and textile needs, without compromising the ability for current or future generations to meet their needs. It can be based on an ...

References

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Sustainable agriculture Tropical agriculture Deforestation Forest management Soil improvers {{Agri-stub

See also

References

External links