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Jeffrey Gogo Climate Story
WORRIED that deforestation could ultimately be bad for business as well as for the environment, the Tobacco Research Board (TRB) has released a new barn design, the kutsaga barn, hoping to encourage farmers to use more fuel-efficient methods of curing their crops. The kutsaga barn is still based

on rocket principles, but is a much finer improvement on the rocket barn that was introduced not more than five years ago.

TRB chief executive, Dr Dahlia Garwe, said the new barn aims to improve energy efficiency, cut firewood use and minimise pollution when curing tobacco leaves.

The rocket barn did all that, but the kutsaga barn does it better, she said. The barn is currently being rolled out in Marondera and Karoi, key tobacco producing areas.

“The new barn is bigger in capacity. Although it takes in more in terms of quantity of tobacco at a time, it is actually more efficient than the rocket barn in that it will burn less fuel per kilogramme of tobacco,” said Dr Garwe last week, by telephone.

The rocket barn derives its name from its ability to draw in dry air using exhaust smoke, rather like a rocket which gains its upward thrust from exhaust. As for the kutsaga barn, well, the TRB “is looking for a much nicer name,” she said.

Zimbabwe is the world’s largest producer of flue-cured tobacco after China, Brazil and the United States.

However, with the number of small-holder farmers growing tobacco tripling to 100 000 since 2011, plantation forests and natural woodlands – key to stabilising the climate at both micro and macro levels – have suffered great damage.

Farmers destroy a total of almost 50,000 hectares of forest each year gathering wood to cure tobacco, according to the Forestry Commission.

This is due to ignorance, poor farming practices and, until recently, a lack of alternative options.

According to data from the UN Food and Agriculture Organisation, Zimbabwe has around 15,6 million hectares of forest – much of it sparse, dry or open canopy forest.

Between 1990 and 2010, the country lost 29,5 percent of its forest cover, an average of 327 000 hectares per year.

Now, the TRB, which has been researching on tobacco for the past 100 years, is looking for new ways to reduce the 15 percent share of deforestation accounted for by tobacco production, and to ensure the crop is grown sustainably.

Improved energy efficiency

One strategy for achieving that goal is the kutsaga barn. Unlike the rocket barn where air enters the curing room randomly, the kutsaga barn introduces air uniformly, helping to extract more heat from the hot fluid, said Wisdom Munanga, an agricultural engineer with the TRB.

“There hot flue have more residence time in contact with the ambient air, thereby enhancing more heat exchange,” Munanga said, by email.

“There are no flue pipes involved in the new barn, making it cheaper and easier to construct and maintain. In short, it has low fuel consumption despite its capacity, 45 000 leaves per cure, compared to 15 000 leaves in the rocket barn per each curing cycle.”

It also improves the quality of the cured leaf, he added. With the old barns, the tobacco leaf would be damaged due to excessive heat from metal pipes.

Mr Munanga said the kutsaga barn is designed to promote high-combustion efficiency, minimising the release of ozone pollutants into the air. As a result, it uses up to 62 percent less fuel wood than the rocket or conventional barns.

Where before the conventional barn used 9kg of wood to cure a kilogramme of tobacco, and the rocket barn between 4 and 4,5kg, the kutsaga barn uses just 3 to 3,5kg.

The rocket barn has a grass insulation 50 mm thick on its higher parts meant to boost efficiency.

With the new barn, it is the bottom of the firebox that is insulated using broken pieces of kaylite, making it much more efficient, said Munanga.

The kutsaga chimney is built inside the barn to make use of waste heat. That compares with the rocket barn’s larger diameter-sized chimney, which removes smoke from the furnace and expels moisture from the barn.

Costing just $782, many farmers will find the new barn much cheaper to build compared to the rocket barn, which costs $1 600.

Centralised curing

Some experts believe there is a better way of tackling tobacco-related deforestation – centralise all curing, make it communal, they say.

This way, the industry will minimise the existing chaos which allows each of the 100 000 small growers to cure their own leaf using illegally obtained fuel-wood, argues Mr Tich Mushayandebvu, head of operations, UN Industrial Development Organisation in Harare.

“Instead of the small farmer trying to cure their crop, and doing a terrible job of it, in the end losing the crop’s value, that tobacco can be transported to a central place where it can be cured more efficiently to retain its value, giving the farmer a better return,” said Mr Mushayandebvu, in an interview.

His choice of energy for such a centralised curing plant is solar, helping to cut the current levels of deforestation linked to tobacco production. But just how could such a plan work, especially in an industry punctuated by individualism and distrust? Who will run the centralised curing stations?

“My thinking is that this has to be a privately operated system,” said Mushayandebvu.

“We need to find an investor willing to pilot the project say with 40 small-scale farmers in a small area like Rafingora or Banket in a contract type of arrangement.

“Farmers grow the leaf, the private investor harvests, transports, processes, cures, packages and sells as a cluster (for the farmers).”

Centralised curing is successfully used in China where several curing barns are installed in rows in a vast open space, helping to improve the leaf quality, lower curing costs and use more efficient energies.

Dr Garwe is less convinced that kind of a plan will work in Zimbabwe. “It (centralised curing) is something that has been considered at a local level, I know Boka Tobacco has considered it, but I do not know whether it will work given the local dynamics,” she said.

“The main issue is that people need to understand right from the beginning what the deliverables are, and to understand the reasoning behind it, and then we can have public buy-in.

“Without doubt, communal barns will introduce certain kind of efficiencies, but this may be difficult in our environment. We are generally selfish here, people just do not like working together.

“You can see this in the new resettlement areas where you have common curing facilities, the troubles that arise when people are deciding on how to use those facilities, one can write an entire book on it.”

As part of strategies to curb deforestation, Government passed a law in 2012 restricting the use, trade and movement of firewood. It also requires smallholder tobacco farmers to establish a hectare of fast-growing eucalyptus for every 10 hectares of tobacco grown.

God is faithful.

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