Malawi - Commercial Agriculture in Thyolo and Mulange

As previously mentioned, most of the commercial agriculture estates in Thyolo and Mulange have several crops grown on a large scale but concentrate on one crop as their strength.  These crops will each have an associated type and amount of waste.  Along with this, there will be waste from supporting exercises such as carpentry and engineering works.  Thirdly, it is expected that, due to the potentially high labour population of the estates, there will be rather high levels of human waste and some municipal waste also.

At this point, the exact waste products which will be focused on for energy recovery have not been finalised as relevant data collection is still in progress.  It is assumed however that, owing to the time available, investigating agricultural, human and municipal waste will be too broad a study and only lead to weak investigations.  However, potential feed stocks for energy recovery could be obtained from the following:


Processed Tea (Leaves and Fibre) in Thyolo
Tea is grown extensively in Malawi, particularly in the South, and “is the second largest producer of tea in Africa after Kenya. Malawi produced 41.6 million kilograms of tea in 2001”[1] and “it contributes some 7.9% of total export earnings”[2]  Approximately 25 000 hectares[6] of tea is grown in the Thyolo and Mulange area and is grown for its leaf which is processed into black tea (left side of picture).  It is a perennial crop which is plucked by hand and so, apart from pruning once every several years, the leaves are the only part of the bush that leaves the field.  Consequently, the leaves and by-products of the leaves are the only regular waste product which could be used as a feed stock.  The usual waste products associated with tea production are rejected or over-withered leaf, tea fibre (the stalks of the leaf shown on the right side of the picture) and tea dust (very small pieces of leaf).  With the exception of the rejected and over-withered leaf, which would require drying, the waste products are dry and so could be used in a thermal energy recovery process immediately.  With regard to pruning, the pruned bushes could be treated as timber would be.

Macadamia Nuts

Macadamia Nuts in Tree
“Malawi produces an average of 5 metric tonnes of macadamia nuts per year”[1] and is "among the most important cash crops in [the country with] total area under macadamia cultivation [at] 2,200 both smallholder farming and large-scale estates"[4].   Macadamia nuts leave the field in their shell and are then shelled and hulled in the factory process.  The shell and hull are the waste products and could be used most effectively in a thermal process due to their high calorific value of around 10 000BTU/lbs[3].  Alternatively, as they are an organic waste, they could be composted.


Tobacco Plants
Malawi produced 124.7 million kilograms of tobacco in 2001 [and] is the main foreign exchange earner accounting for about 70% of total exports and it has continued to dominate the trade returns for Malawi”[1].  The main waste associated with tobacco is mouldy stem and scraps.  This waste would be relatively dry and so appropriate as a fuel for a thermal energy recovery process, or alternatively, as a composting ingredient.  Further data analysis and collection is required to determine whether enough waste is produced in the production of tobacco to merit energy recovery research.


Eucalyptus Plantation in Thyolo
Most commercial agriculture estates in Thyolo and Mulange have some timber plantations for various reasons such as fuel for boilers, construction material and fire wood.  In the southern region, the most common timber is Eucalyptus as it is a very fast and straight growing perennial timber with a maturation time of 7 years.  Whilst data for exact quantities of timber produced on estates in Thyolo and Mulange is currently being obtained, it is assumed that any large estate with several crops will have a fairly significant area dedicated to timber.  Furthermore, as a large percentage of the timber grown by an estate is done so for fuel for boilers and fires, a thermal energy recovery process could in fact make use of both the timber waste and the timber harvest itself and even potentially improve the current fuel to energy/benefit ratio.  Additionally, scraps and sawdust from an estates carpentry department could be used as a fuel also.


Unprocessed Coffee Beans
“Malawi grows Arabica type of coffee with an average production of 4,176 metric tonnes per year”[1].  Coffee pulp is a by-product of wet coffee processing which would require drying before it can be used in a thermal energy process.  In its moist state, it could potentially be composted.  Parchment is another by-product but is only obtained after the processed coffee has been dried.

Human Waste

The population of a commercial estate in this area can be quite high, in the region of several hundred or several thousand people.  This is due to high numbers of employed labour who are often housed with their families on the estate.  Sewerage systems on agricultural estates are usually minimal with very few houses having running water or flushing toilets.  The vast majority of the human waste is therefore collected in latrine type systems where when filled, it is simply covered over.  This therefore represents a large amount of unused energy, which could be recovered.


Maize Field
In the 2002/3 maize season, 1.983 million tonnes of maize was produced in Malawi and in the 2003/4 season, 1.733 million tonnes was produced[5].  Maize is a staple food in Malawi so it is likely that current figures are relatively similar.  This gives an idea of the quantity of maize that Malawians consume, especially as Malawi is generally a net importer of maize.  As most estates feed their labour on a daily basis, they usually grow substantial amounts of maize rather than buy in large quantities and, consequently, have to deal with the by-products.  The by-products associated with maize are the stover (stalk and leaves) and cobs, which are either burned, composted or land filled.  When dry however, both of these could be a potential fuel for a thermal energy process.

Livestock and Poultry Waste

Jersey Cow
Many estates in Thyolo and Mulange run beef and dairy cattle herds along with sheep and in one case chickens.  The livestock and poultry is predominantly run for internal consumption with any excess beingb sold on the open market.  Typical cattle herds in the area tend to be under 100 strong and slightly less for sheep.  In the case of the estate rearing chickens, the flock numbers several thousand as the operation is run as a commercial unit.  As only the one estate rears chickens in large numbers, it is thought that chicken waste will be ignored in this study.
Solid waste from cattle and sheep should be considered at the outset as energy recovery from such waste could be significant depending on the exact herd and flock numbers.  It might be suggested that human waste and livestock waste could be treated in a similar way, reducing the energy recovery start-up costs and physical space and number of locations required to carry out the energy recovery process.  Combining waste amouns from these two sources also has the advantage of increasing the level of fuel available to justify any potential energy recovery process.

This list is not exhaustive and may change as data collection continues.


[1] Malawi Confederation of Chambers of Commerce and Industry, Highlights of Malawi Export Products, Food Stuffs, Accessed on 30.10.2009
[2] Malawi Confederation of Chambers of Commerce and Industry, Agricultural Sector Business Opportunities in Malawi, Tea Production and Processing, Accessed on 30.10.2009
[3] Rosengarten, F. "The Book of Edible Nuts", Walker and Co New York, 1984
Picture courtesy of the Harnakua Macadamia Company, Accessed on 30.10.2009.
[4] Malawi Confederation of Chambers of Commerce and Industry, Agricultural Sector Business Opportunities in Malawi, Macadamia Nuts Processing, Accessed on 30.10.2009
[5] National Statistics Office of Malawi, 2003/04 Agricultural production estimates survey results, Table 1: Production of selected crops 2004, Accessed on 30.10.2009
[6] Stephen Mullan, Chairman of the Tea Association of Malawi, 2008/09 (03.11.2009),
Picture of tea taken by Alasdair Walker
Picture of jersey cow courtesy of Accessed on 01.11.2009.
Picture of macadamia nuts on tree courtesy of (Provided by th Harnakua Macadamia Company,  c 2006) Accessed on 30.10.2009.
Picture of tobacco plant courtesy of Accessed on 30.10.2009.
Picture of Eucalyptus plantation
taken by Alasdair Walker.
Picture of coffee beans courtesy of Accessed on 30.10.2009.
Picture courtesy of Accessed on 30.10.2009.

Home      Back      Arran Feedstocks