By Kikonyogo Ngatya
THE harvesting season is here again. Many farmers concentrate on the yields and look at crop left overs as a burden in the field. Some burn them while others use them as mulch for other crops, especially coffee and banana plantations.
When chopped into smaller and easy to swallow pieces for the livestock, it can increase the animal nutrition for more milk and beef, according to a study by Dr Jolly Kabirizi, published in The Journal of Agricultural Sciences.
But there is a new use, which can fetch more money when the left overs from the stem to the leaves are turned into charcoal for cooking.
Charcoal briquettes offer a much cleaner and higher burning capacity than that of wood, according to a study by Agro Rural Technology Initiative (ARTI-UG), as displayed during the recent Source of the Nile Agricultural Show in Jinja.
Currently, many youth in villages cut down trees to make charcoal at the expense of environment. Basic charcoal is produced by burning a carbon-rich material such as wood in a low-oxygen atmosphere. This process drives off the moisture and volatile gases that were present in the original fuel. The resulting charred material not only burns longer and more steadily than whole wood, and it is much lighter.
â€œFarm waste is not a burden. It can be transformed into charcoal or even gas for cooking,â€ the study notes.
K.Potavis one of the scientists promoting the technology said the briquetts are easy to make, even at home.
Four small metallic drums are cut open and filled with dry farm residues. They are then placed into a bigger drum, with some space left in between them.
Potavis explained that small quantities of dry residues are placed in the spaces between the drum inside the big one. The small drums are then covered, together with the big drum, but with an opening at the lid of the big metallic drum to let off smoke.
The residues in between the small drums are lit. After about forty five minutes, the grass or residues in between the small drums turn into ash, while the residues inside the small drums form a black, charcoal-like substance. Leave them to cool then pound the black burnt substance into powder.
Add it with water and mingle using a stick or in a machine. A small machine used to mince meat is then used to produce bigger charcoal briquetts. â€œBut it is important that the part that produces the briquetts is modified so that they come out bigger. Local artisans can do this,â€ Potavis said.
The briquettes are at this point squeezed out and are the side of the machine outlet. Place them under the sun or solar drier to dry. â€œThis is an environmentally friendly way of making charcoal. Since most Ugandans depend on wood fuel, this kind of charcoal is ideal,â€ according to the study.
â€œThey light faster and are made of pure carbon and magnesium. They also burn longer compared to ordinary charcoal, some of which is made from soft wood which may not be good,â€ the study notes . Out of a tonne of farm residues, between 30 and 40kg of pure dried charcoal briquettes can be made.
Potavis said they were embarking on a drive to senstise farmers in rural environs to save trees by turning to briquettes since they are easier to make and save the environment.
He said charcoal is a more desirable fuel because it produces a hot, long-lasting, virtually smokeless fire.