Beyond the Ashes of Devastation
Poku Adaa
The year 1983 was the year in which bush fires devastated farmlands in the tropical West African region. POKU ADAA discusses the long term effects of bush fires on soil capabilities and the damage to the ecology of rural environments.Last year, 1983, lack of rainfall and dry winds from the north gave rise to large scale bush fires which swept through farms and villages in the Ivory Coast, Ghana, Togo and Benin. The obvious visible effects of the conflagrations was the loss of farm produce and incomes as cash crop plantations and food farms succumbed to the ravages of the fires. In addition to those, there are long term effects that may not be easily calculable and which may not be so immediately apparent although measures taken today may avert the destructive outcome in the next decade or so.
In the Ivory Coast, reports estimated about 250,000 hectares of cocoa and coffee plantations were destroyed along with rural and village settlements. In Ghana, every region of the land had its share of bush fire carnage. From Nsawam to Kibi stretching up to the edge of the Afram plains in Begoro and onto the Kwahu hills, in the Volta Region and in the Western and Brong- Ahafo Regions, fire raged day after day fuelled by strong winds and intensive drought. Similar outbreaks occurred in neighbouring Togo and Benin. The invisible effects after the fires have died down and the belated rains have trickled down, are worth considering in order that normal ecosystems can be aided to restoration.
After the havoc of fires, vast areas are laid bare and exposed to the later rains and the incidence of soil erosion becomes more acute especially along mountainsides and hilly areas, like Kwahu ridges in Ghana lying between Nkawkaw and the hill-towns of Obo, Mpraeso and surrounding villages. Soil erosion upsets the balance in the landscape as more soil is lost than can be reproduced naturally. The runoff from erosion are deposited, in the form of sediments or earth rubble, in nearby drinking water sources causing severe water pollution and long term health hazards.
Sometimes floodplains and irriga- tion schemes become recipients of soil erosion deposits, choking the canals and impeding water flow and distribu- tion. Besides, soil erosion washes away the soil nutrients most particularly on newly fertilised farmlands. Soil carbon is easily lost and cannot be replaced. The effects of soil erosion can be measured in terms of the amount of sediments deposited away from sloping landscapes and in countries with similar experiences of bush fires, rates of up to 34,000 tonnes per square kilometre per year have been recorded.
EXPERIMENTS
A direct result of bush fires even when there have been no later rains to cause soil erosion, is the loss of soil nutrients which just turn into vapour due to the heat of the raging fires. Particular crops like cereals need the chemical element sulfur as a necessary nutrient and this sulfur exists in the soil in an organic form which easily burns into the atmosphere. Thus bush fires completely deprive soils of their organic nutrient contents and yields of cereals like maize, rice, millets, may be reduced in the cropping season after the bush fires unless artificial fertilization is encouraged right away.Experiments conducted by some North American scientists have revealed that up to 50 percent of fertilizers applied to farmlands may often be lost as a result of burning lands. There are also crops like beans, peas, groundnuts, who depend on specific soil micro-organisms to be able to contain soil nitrogen. If these organisms are burned out or destroyed by fires, it is certain that these crops cannot be sustained unless regular planned fertiliser applications are actively encouraged on a massive scale after the fires have died down. There are yet more soil organisms which ordinarily help to retain soil moisture, absorb and retain salts essential for healthy growth of plants, and all these natural cycles are destroyed by bush fires.
Let's take the example of termites, harmless creatures who do a marvellous job of digesting rotten wood and recycling the nutrients back to the soil. Beetles, larvae, fungi, all do similar jobs as nature has apportioned to them. Whole farmlands and forests depend on these invisible do-gooders and bush fires do no more greater menace then devour these helpless creatures who are part of this life of ours. Recent reports indicate that in Guinea, rice farms which usually produced 300 kilograms per hectare in 1976 could only return one-tenth of that, 30 kilograms, the year after the lands were devastated by fire outbreaks. Guinea, like other West African countries, has had her share of fires in the past. Between 1975 and 1978, over 160,000 hectares of farmlands were ravaged by fire and agricultural output in the years that followed were catastrophic.
There are other less appreciated effects of bush fires. There is the complete elimination of wildlife and many other medicinal vegetation which mean so much to rural communities, a situation which send ripples across the corridors of conservationists camps. In Ghana, for instance, although statistics are not available, the country has lost, over the last twenty years, several unique species of animals. Wild pigs, for instance are practically extinct these days just like many others.
There is reason to believe that in areas of West Africa where economic hardships do not allow room for any effective wildlife conservation, bush fires are only a worsening addition, out to exacerbate the problem. The next generation will perhaps have to contend with a half populated world contrary to natural laws of existence. And not only that, the natural cycle of reforestation tend to break as forest trees suddenly turn into oaks in a Scottish winter, completely denuded of leaves and freshness.
Most natural vegetation are multiplied by 'Pollination' by birds, bats and insects and when these creatures are killed in bush fires or driven away by the obnoxious smell of carbon monoxide or other emissions from burning wood and leaves, it creates a break in the natural cycle of vegetative production. The effects of these in the next ten to twenty years is unimaginable.
Now what can be done? There are two things: a comprehensive reforestation and replanting programme, both to check soil erosion and to restore vegetation. Secondly, mixed cropping on devastated farmlands can help raise some crops where others, because of loss of particular nutrients in the soil, can no longer thrive well. Soil erosion can also be checked practically by the building of tough ridges across the usual direction of runoff flows. But above all, more wildlife and plant conservation programmes may be needed in the short term.
Finally, farmer reassurance and education on these matters are crucial.
