Soil Erosion: Causes, Types, Effects, and Prevention Methods
Learn about soil erosion, its causes, types (sheet, rill, gully, wind, and splash erosion), and its impact on East Africa. Discover practical solutions to prevent soil degradation.
SOIL EROSION
Soil erosion simply refers to the removal or wearing away of the topsoil by agents such as wind, running water and glaciers. In East Africa, running water is by far the most important, widespread and destructive of the three. Soil erosion is mostly noticed in areas where the rate of soil removal is greater than that of deposition or soil formation. Soil erosion mainly occurs in areas where there is little or no vegetation cover e.g. in arid and semi-arid areas. In such areas, the weathering processes are present but there is no vegetation cover to protect the developing soils, which are then removed as soon as they are exposed to wind, glaciers or rain.
Types of soil erosion
Sheet erosion
This type of erosion results in the removal of a uniform depth of soil by surface run-off or wind. It affects large areas and it occurs when rain falls on a gentle slope or wind blows over a large area which is bare of vegetation. The process of soil removal is slow and it takes years to notice it e.g. Yatta and Uasin Gishu plateaus of Kenya.
Rill Erosion
This is an erosional process in which numerous small channels of only a few centimeters formed. Water is the main agent of rill erosion. it takes place in areas of both gentle and steep slopes. Itis the first stage of gully erosion.
Gully erosion
This is the advanced stage of rill erosion. It is an erosional process whereby water usually after heavy rainstorms accumulates in narrow channels over the landscape. Over a period of time, the water leads to the formation of well-defined depressions ranging from about 0.5 to 30 meters known as gullies. Gully erosion is most serious in areas where rainfall is heavy and where the slopes are steep e.g. in Uluguru Mountains and Dodoma region in Tanzania and Kabarole, Sironko, Kapchorwa, Kabale and Kisoro in western Uganda.
Wind erosion.
Wind is another active agent of erosion, especially in arid and semi-arid climates with rainfall less than 750 mm and which experience a very marked dry season. The low rainfall results in little or no vegetation cover. Wind blowing across such bare land lifts particles of sand and silt but leaves behind the larger pebbles and particles. Eventually, a surface layer of closely packed stones is formed as the sand and silt is removed. The removal of large quantities of loose material is called deflation. The areas affected by wind erosion include Moroto, Kotido, Katakwi, Soroti, Amuria, and Pader in northern and north eastern Uganda and most of northern Kenya such as Lodwar, Mandera, Marsabit and Wajir. The eroding and transportation power of wind involves the actual removal of dry unconsolidated material.
Splash erosion
This is the detachment of small soil particles caused by the impact of falling raindrops on unconsolidated soils. It is called slash erosion because the soil particles are splashed away by the force of the falling raindrops. It is common in arid and semi-arid regions like Karamoja and Kondoa incentral Tanzania.
CAUSES OF SOIL EROSION
Physical factors
Relief
Relief refers to the nature of the landscape. The rate of soil erosion is determined by the nature of the slope in terms of its length and steepness. Hilly areas are more prone to severe erosion than the undulating and gentle landscapes. The gradient in these hilly areas offer the required force for the removal of the top soil by running water by accelerating surface run off. In hilly areas, the steepness of the slope and its length play big role in enhancing soil erosion. The steeper the slope and the longer its length, the more the soil erosion. Area which experience soil erosion due to steep slopes include Kadam region in Karamoja, Kabale, Kisoro, Bundibugyo, Kapchorwa and Kabarole in Uganda, Uluguru, Kondoa and Dodoma areas in Tanzania, and Machakos, Kiisi and Baringo in Kenya. Most of the above areas suffer from gully erosion because of the steep rugged terrain.
Climate
This provides the agents of erosion, which are wind, running water and moving ice. The type of erosion agent varies with climate. Rainfall can be singled out as the most important climatic factor contributing to soil erosion in East Africa. The dominant factor on the amount of run-off and soil loss is usually the frequency of high intensity storms rather than the total annual rainfall. A number of areas in East Africa receiving heavy rainfall experience erosion by surface run-off and vertical erosion by leaching e.g. the Lake Victoria basin.
In arid and semi-arid regions, the unreliable and erratic rainfall causes soil erosion. The erratic heavy rain results in slash, rill and sheet erosion. The loose dry soils, which had formed during the dry season, are easily carried away by erratic rains .e.g. Turkana in northern Kenya and Karamoja in Uganda. These rains fall in heavy showers and within short periods of time carrying away the large quantities of the top soil. In fact, most of East Africa's rains that break a period of drought are heavy.
Wind erosion is concentrated in the arid and semi-arid areas of East Africa such as Masailand, Turkanaland, Lodwar, Mandera in Kenya and Kumi, Soroti, Katakwi, Kotido, and Moroto in Uganda. Extensive wind erosion is pronounced during the dry seasons because the soils remain exposed to wind during prolonged dry months.
Glacial erosion in East Africa is confined to height above 4700m above sea level where temperatures can fall below freezing level e.g. on Mt. Kenya, Kilimanjaro and Mt. Rwenzori.
The combination of steep slopes and heavy rainfall results in devastating soil erosion. This was particularly the case during the intense El Nino rains of 1997-1998 in many parts of East Africa. Productive gardens of vegetables, potatoes and other crops were covered with sand and stones or the topsoil washed away from upper slopes.
Vegetation
Thick vegetation such as that provided by tropical rainforests reduces soil erosion as the tree roots help to bind the soil particles together while the leaves reduce the force of the falling raindrops. The vegetation further reduces the surface run-off and soil transportation. Therefore absence of a vegetation cover makes the soil particles to be loose, accelerating their removal by surface run-off. This is the case in parts of Iringa and Dodoma in central Tanzania where the natural vegetation consists of dry bush savannah. This vegetation largely consists of scattered grasses with bare sand between them hence offering little protection to the soils.
Nature of soil
The nature of soil texture influences the rate of erosion. This is in terms of finess or course-ness of the soil texture. Areas with fine textured soils are vulnerable to erosion e.g. the volcanic ash soils in Kisoro in south western Uganda and on Nyambeni Hills north of Mount Kenya. Structurally stable soils do not easily detach and therefore less vulnerable to soil erosion. On the other hand, the structurally unstable soils are detached and easily moved by agents of erosion. Such soils include the sandy soils which are common in the drier areas of Marsabit, Mandera, Turkana in northern Kenya, Morogoro, Dodoma and Iringa in central Tanzania and Karamoja in north eastern Uganda. Furthermore, soils high in salt content such as those in Kasese and Semliki areas are prone to gully formation as the salts are removed in solution.
Human causes of soil erosion
Over grazing
In many places in East Africa, especially in the semi-arid and arid areas, large numbers of animals are still kept for prestige among other purposes. This usually leads to the rearing of animals far beyond the carrying capacity of the land. The land becomes overgrazed and the soils remain exposed to agents of erosion especially running water when the rains begin or wind in the dry season. The animals also form intermeshing paths, which turn into rills and galleys during rainy seasons. This is very common in pastoral communities like Karamajong in north eastern Uganda, Turkana region and the Masailand.
Bush burning
This is a practice of practice of burning off old grasses at the end of the dry season. The cultivators use it in preparation of the fields for planting before the rains begin e.g. in Gulu, Lira, Soroti and Kumi. The pastoralists practice bush burning in anticipation of the growth of fresh pastures on the onset of the wet season. However, when the rains begin they find bare ground carrying off large quantities of the top soil. The above condition is experienced in parts of Mbarara, Nakasongola, Masailand, Turkaland and Karamoja were pastoralism is practiced. A part from promoting soil erosion, burning kills the micro-organisms thus robbing the soils of organic mater which leads to the deterioration of the soil structure.
Clearing of vegetation
Vegetation especially forests reduces the rate of soil erosion as the tree roots help to bind the soil particles together. Any continued unplanned cutting of trees without appropriate replacement exposes the soil to agents of erosion like running water and wind. The cutting down of forests especially on the higher slopes results in soil erosion and the spreading out of the transported soil over the lowlands. This is what is happening in Kenya and Kigezi Highlands as man attempts to collect firewood, make charcoal or cut wood for industrial purposes. Such bare surfaces are vulnerable to heavy soil erosion. In the Uluguru Mountains in Tanzania, almost all the lower altitude forests has been cleared and replaced with farmland and villages and hence experience soil erosion.
Poor cultivation methods
There are various poor farming methods, which lead to soil erosion in East Africa some of which are discussed below;
Monoculture
This refers to the practices of growing the same type of crop year after year without the application of fertilizers or manure, which impoverishes the soil making it loose its cohesiveness and soil erosion sets in e.g. banana growing in Mbarara, Budadiri, and Masaka, tobacco growing in West Nile and coffee on the slopes of Mount Elgon.
Nature of crops grown
Some crops offer little protection to the soil against soil erosion especially when they are still young e.g. cotton growing Lira, Dokolo and Soroti. This is made worse for crops, which are grown in rows because the soils between the rows are exposed to agents of soil erosion. Crops such as cotton and tobacco generally offer very little protection to the soil against erosion.
Ploughing of land up and down the slopes.
The cultivation of steeply sloping land without the use of adequate measures to check the rapid run-off of surface water leads to soil erosion. The ploughing of land up and down the slopes leads to the formation of man-made channels, which can be enlarged into gullies by surface run-off. This is mainly the case in the highlands of Kapchorwa, Bukwo, Manafa and parts of Kigezi.
Cultivation of crops in regions which do not have a reliable rainfall.
The cultivation of crops in regions which do not have a reliable rainfall i.e. dry years following wet years and which have only sufficient rainfall for crop farming. The crops use up the available little moisture which would have been used to support a natural vegetation cover.
Shifting cultivation
In shifting cultivation, a piece of forest is destroyed by fire and crops are grown in the soils of the cleared patch which are now enriched by wood ash. After 2-3 years of cultivation, the patch is abandoned and a new clearing is made. The abandoned, exposed part soon experiences soil erosion by rainfall. It is important to note that in many parts of East Africa shifting cultivation has died out due to increase in population and hence no land to keep shifting to.
Population pressure
In some parts of East Africa, population is rapidly increasing and this is exerting pressure on the available land. This has resulted into shortage of land suitable for cultivation. In Kabale, Kisoro and Rukungiri in western Uganda, and in Kikuyuland, Kiisi and Nyanza areas in Kenya the land is over used by growing crops on the same piece from season to season without giving it ample time to rest to regain its fertility.
The continued use of small parcels of land quickly exhausts the soils, leads to deterioration in the texture of soil, making it susceptible of both sheet and gully erosion. In addition, the high population has resulted in land fragmentation in the heavily populated districts of Kisoro, Kabale, Rukungiri, Kapchorwa, Mbale and Bushenyi, which hinders the use of proper soil conservation measures.
Mining and quarrying.
Open cast nature of mining and quarrying disrupt the soil structure exposing it to erosion. In addition, mining involves the removal of vegetation which affects the stability of the soils e.g. limestone miningin Tororo and Hima, and quarrying at Mbalala in Mukono district.
Construction of roads and buildings.
These leave the ground unprotected and generate large volumes of surface runoff that cause both on- site and off-site soil erosion. In Uganda, for instance most roads have murram surfaces e.g. Mpigi- Gomba road, Soroti-Moroto road and Fort Portal Bundibugyo road. The large volume of surface runoff generated on roads particularly those poorly constructed without adequate drainage, culverts and drop inlet structures lead to serious soil erosion. In addition, most homesteads in rural areas of Buganda, Busoga and Gulu leave a large area in the form of compounds and courtyards exposing the soils toagents of erosion.
CASE STUDIES
Kigezi Highlands
Photo showing Kigezi area.
Causes of soil erosion.
· Over-cropping due to increased population. The land is used over again without being givenrest.
· Monoculture i.e. growing some crops year after year.
· Deforestation of steep slopes.
· Steepness of the slopes accelerates surface run-off of water.
· Nature of rain falling with intensity i.e. heavy raindrops hit the ground resulting in movement.
· Nature of soils.
Karamoja region of N.E Uganda
Causes of soil erosion:
· Hilly nature of the landscape.
· Nature of soil i.e. easily eroded.
· Nature of rainfall received. Rain falls in heavy showers within a short period of time resultingin soil-wash.
· Overgrazing resulting from overstocking.
· Burning of vegetation
· Deforestation on hill slopes.
· Growing of crops in areas with unreliable rainfall.
· Drought which kills off any vegetation.
Kondoa District of Tanzania
Causes of soil erosion:
· Steepness of land,
· Nature of soils:- unstable easily eroded.
· Nature of rain falling with high intensity.
· High population density resulting in over cropping
· Overgrazing.
· Deforestation.
Kenya Highlands
Causes of soil erosion:-
· High rainfall falling with high intensity.
· Slopes are steep accelerating surface run-off.
· Increasing population densities leading to over cultivation.
· Nature of main crops grown: maize, which gives little protection to the soil.
· Deforestation.
EFFECTS OR CONSEQUENCES OF SOIL EROSION
The most obvious effect of soil erosion is the loss of soil productivity and subsequently low crop yields in the eroded areas such as in Karamoja, slopes of Mt. Elgon and central Tanzania. The surrounding areas, although not themselves eroded may also suffer a reduction in productivity, as a result of eroded material being deposited over them. It is usually, the coarser and less fertile particles of soil, which are deposited on the surrounding areas, while the finer and more fertile particles are transported longer distances.
Soil erosion results in the deterioration of underground water supplies leading to the drying up of boreholes and wells in Sebabule, Isingiro, Moroto and Nakapiripirit. This is because a high proportion of the rainwater runs directly at the surface instead of being absorbed by the soil.
Soil erosion also results in flooding. This is because water reaches streams by overland flow rather than by soil through flow. Soil generally retains part of the rainwater, which falls on it, only gradually releasing in to streams and rivers thus helping to regulate the flow of water throughout the year. In areas where the top soil has been removed most of the rainwater runs directly into the streams and rivers. As a result, rivers tend to flood immediately following periods of heavy rain but during periods of dry weather, their flow is abnormally reduced. Most bridges in Karamoja are high because of this reason. Rivers such as Moroto, Dopeth, Agule, Chapeth and Okok in Karamoja suffer fluctuations in water level limiting the usefulness of rivers as means of transport and source of hydro- electric power.
Severe soil erosion is responsible for the rapid silting up of reservoirs and harbours. The water storage capacity of reservoirs is considerably reduced as a result of the deposition of large quantities of silt c.g. in Mbarara, Kiruhura and Isingiro. The depth of water in harbours which are located at the mouth of Henry M. Kichodo rivers may also be greatly reduced by the deposition of silt. Costly dredging operations become necessary.
Soil erosion results into the deterioration of water supplies and increasing costs of purification. Rivers originating from Mount Elgon for example carry large quantities of sediments especially during the rainy season. The water purification station on River Manafwa, which supplies Mbale town, and River Malaba, which supplies Tororo town, suffer increased costs during heavy rains.
Soil erosion leads to frequent occurrence of landslides. Although landslides may occur without soil erosion, this is only where there is exceptionally heavy rains or earthquakes. Landslides thus mainly occur in areas severely hit by soil erosion such as Bududa, Bulambuli and Bulucheke on the slopes of Mt. Elgon.
Gullies resulting from soil erosion cause two main problems to the agricultural land. Where they occur across fields, agricultural land is destroyed as well as making cultivation difficult. They are also an indication that fertile top soil for agriculture has been washed away e.g. in Kondoa region of Tanzania as well as in Kabale and Kasese. Secondly, they help to lower the water table and this makes it difficult for short-rooted plants to survive.
Soil erosion affects transport systems particularly roads. In some places, roads are covered with great patches of material, which has been swept down from the hills during a period of storm. The tarmac roads have always to be kept cleared of this material. On moving around Kampala City, one cannot fail to see roads covered by large quantities of soil deposited after a rainstorm from the surrounding hills of Namungoona, Muyenga, Makerere, Rubaga and Namirembe hills.
Severe soil erosion promotes drought and desertification especially in the arid and semi arid regions of Baringo and Marsabit in Kenya and Karamoja in Uganda. Overgrazing leaves the land bare and once rain falls, large quantities of the top soil are washed away from the bare patches. Once the top soil has gone, it is difficult for the grass to re-establish itself. The lands become bare, barren and ultimately drought and desertification set in.
Positive effects of soil erosion
Eroded soils especially from highlands are deposited on the lower slopes leading to the formation of deep soils which sustain agricultural production e.g. on the lower slopes Mts. Elgon and Kilimanjaro.
Soil erosion has led to the exposure of out crop rocks which are quarried to provide building materials e.g. in Kachumbala in Kumi, Nakasongola, and Mubende.
Soil erosion has led to the exposure of minerals of importance to man e.g. the wolfram bearing rocks at Nyamiriro mine in Kabale and limestone bearing rocks at Tororo.
Soil erosion leads to the exposure of new un-leached rock which helps in the formation of fertile soils. This has been the case in Hera Juu plateau of north west Tanzania, cultivation takes place on top of the ridges because it is there that the soils is being renewed most rapidly.
SOIL CONSERVATION
This includes using important methods, which check soil erosion. Always prevention is better than cure. The methods of controlling soil erosion include the following:-
Afforestation
Very steeply sloping hillsides should not be brought under cultivation but rather be kept under forests. Forests provide the most complete protection against soil erosion than any other type of vegetation. The trees reduce the force of the falling rain while the tree roots bind the soil particles together. Afforestation is practiced in the Kigezi and Kenya Highlands.
Re-afforestation
This includes re-planting of forests where they have been cut e.g. in the Mt. Elgon Forest Reserve. Many tree nurseries have been established for this purpose. Such programmes are publicised by mass media campaigns using slogans such as 'cut one, plant two".
Agro forestry
Agro forestry is the growing of trees and crops on the same farms to improve the livelihood of the rural farmers as well as to protect the environment especially the soils from erosion. Agro forestry provides one way of improving soil fertility. Trees and shrubs with many uses improve soil fertility by capturing nutrients from deep layers of soil, making food (fixing nitrogen from the air) and putting it back into the soil. These trees also reduce soil erosion by holding nutrient rich soil in place and by reducing the rate of run-off. Apart from controlling soil erosion, trees on farms provide farmers with high value products such as food, fruit, medicines, fodder, timber, fuel wood, poles and manures. Agro forestry is practised in areas of Munono, Luwero, Mpigi, and Buikwe.
Terracing
Where population pressure makes it necessary to cultivate steep hill slopes, the land should be protected by terracing. Terracing refers to the cutting of series of wide steps or benches 2-3 metres wide on a hill slope on which crops are grown. Bunds or earth banks are constructed to hold back the surface runoff. Terracing helps to divide the slope into many shorter slopes, which reduce runoff down slope. In Uganda, this method of soil conservation is best seen in the highlands of Kigezi in south western Uganda. The flooding of the terraces is a good indication of the ability of the terraces to prevent soil erosion.
Contour ploughing
In this method, the furrows in which the crops are planted follow the contours of sloping lands to minimize erosion and runoff. This avoids the ploughing up and down of slopes, which leads to soil erosion. Both terracing and contour ploughing form the widest measures being used to control soil erosion in the Kenya highlands, Kigezi highlands, Rwanda and Burundi.
Mulching
This is a farming practice which involves the covering of the soils especially in gardens with bananaleaves, grass or any other vegetation matter. Mulching is a good practice because of its many advantages. It prevents loss of moisture from the soil, improves soil fertility by adding organic matter to the soil, protects the soil from the direct impact of rain drops, protects the soil against wind and water erosion, suppresses weeds, maintains good temperatures for germination, crop growth and the life of soil organisms. Mulching is a common practise in the banana plantations in Bushenyi, Mbarara and on the slops of Mount Elgon where the plantations are mulched with their own old stems and leaves and occasionally supplemented by grass or coffee husks.
Strip cultivation
This a method of cultivation that involves alternating strips of crop and uncultivated land left with grass to minimize erosion and water runoff. This method is mainly used where crops are grown in rows and thus offer little protecting against soil erosion. One strip has the crops while the adjacent strip is under grass or any other type of vegetation. If wind blows or water erodes soil off the cultivated strip, it will be caught by the vegetate strip e.g. on the slopes Mt. Kilimanjaro.
Crop rotation
Crop rotation is the growing of crops in a sequence on the same piece of land rather than utilizing a one-crop system or a haphazard change of crops. In the rotation system, crops are alternated on the basis of the amounts and types of organic matter that each crop returns to the soil. In Soroti, Kumi and Kaberamaido, crops such as maize, sorghum, millet, groundnuts, cotton, cow peas, cassava and sweet potatoes are grown using crop rotation method. This ensures that the soil remains fertile and does not lose its structure. It sticks together better and is less likely to be blown by wind or washed away by running water. Crop rotation has also the effect of reducing pests and diseases.
Fertilizers and manure
Use of fertilizers and manures ensures that the soil remains fertile and does not loose its structure. Organic manures refer to sources of plant nutrients that are naturally occur such plant and animal residues and green manure plants, minerals like rock phosphate that are mined from the earth and used without undergoing any chemical treatment. Widely used organic manures include kraal manure Mbarara, Mbale and Ntungamo, coffee husks in Manafwa and Masaka districts as well as use of other crop residues, household refuse and others. Chemical fertilizers are sources of plant nutrients that are derived from a chemical manufacturing process. In East Africa, chemical fertilizers are mostly used of plantation farms such as Kericho and Kasaku tea plantations, and on floriculture farms in such as Ziwa Horticulture, Nile Roses Ltd, Nsimbe Estates and SCOUL in the districts of Mukono, Buikwe, Wakiso and Mpigi.
Land rotation
This is a system where land is cropped and rested in turns. Annual crops are best considered against the background of land rotation. This is common in the rural areas of Buganda and Teso. However with increasing population there is limited land to practice land rotations.
Cover crops
Creeping legumes such as beans and peas as well as sweet potatoes are commonly used as cover crops and provide a dense protective cover for the top soil e.g. in Kisoro, Kabale, Rukungiri, Sironko and Budadiri. Legumes are preferred because of their Nitrogen Fixation, a biological process by which molecular atmospheric nitrogen is converted into a chemical compound that is essential for plant growth.
Reduction of livestock numbers
In areas where pastoralism is practiced, the number of animals is carefully being regulated in order to avoid overgrazing. This is partly through the establishment of ranching schemes such as Kisozi in Gomba (Mpigi) and Kaputiei ranch in south of Machakos in Kenya.
Water points
Livestock water points are being properly protected and widely distributed to prevent the gully formation along animal paths and to avoid consolidation of soils in Mbarara and Kiruhura.
Planting of shelter belts
Belts of trees are often planted across a flat region, which is liable to suffer from wind erosion. The trees break the force of the wind and thus protect the strips of land between the belts from being eroded.
Tillage
Ploughing or any other form of cultivation which breaks a surface soil crust, will temporarily increase rainfall infiltration and reduce erosion by run-off water.
Sensitization
We used to see soil erosion extending to our homesteads, but we could do nothing to stop it. Now I know how to control soil erosion using the skills acquired from training". This is a statement by a farmer in Matheniko County in Karamoja. The National Environmental Management Authority through mass media is promoting such sensitization in many areas of Uganda such as Kabale, Kisoro, Sironko, Bududa, Bundibugyo among others. Often the local leaders in the respective areas help in the community mobilization.
In East Africa, chemical fertilizers are mostly used of plantation farms such as Kericho and Kasaku tea plantations, and on floriculture farms in such as Ziwa Horticulture, Nile Roses Ltd, Nsimbe Estates and SCOUL in the districts of Mukono, Buikwe, Wakiso and Mpigi.Land rotationThis is a system where land is cropped and rested in turns. Annual crops are best considered against the background of land rotation. This is common in the rural areas of Buganda and Teso.
However with increasing population there is limited land to practice land rotations.Cover cropsCreeping legumes such as beans and peas as well as sweet potatoes are commonly used as cover crops and provide a dense protective cover for the top soil e.g. in Kisoro, Kabale, Rukungiri, Sironko and Budadiri. Legumes are preferred because of their Nitrogen Fixation, a biological process by which molecular atmospheric nitrogen is converted into a chemical compound that is essential for plant growth.Reduction of livestock numbers.In areas where pastoralism is practiced, the number of animals is carefully being regulated in order to avoid overgrazing.
This is partly through the establishment of ranching schemes such as Kisozi in Gomba (Mpigi) and Kaputiei ranch in south of Machakos in Kenya.Water pointsLivestock water points are being properly protected and widely distributed to prevent the gully formation along animal paths and to avoid consolidation of soils in Mbarara and Kiruhura.Planting of shelter beltsBelts of trees are often planted across a flat region, which is liable to suffer from wind erosion. The trees break the force of the wind and thus protect the strips of land between the belts from being eroded.
TillagePloughing or any other form of cultivation which breaks a surface soil crust, will temporarily increase rainfall infiltration and reduce erosion by run-off water.Sensitization"We used to see soil erosion extending to our homesteads, but we could do nothing to stop it. Now I know how to control soil erosion using the skills acquired from training". This is a statement by a farmer in Matheniko County in Karamoja. The National Environmental Management Authority through mass media is promoting such sensitization in many areas of Uganda such as Kabale, Kisoro, Sironko, Bududa, Bundibugyo among others. Often the local leaders in the respective areas help in the community mobilization.
Research
Institutions involved in developing better methods of soil conservation and passing them to farmers include the Forestry Resources Research Institute, International Center for Research in Agro- forestry (ICRAF), and National Environmental Management Authority (NEMA). The institutions also help in the provision of agro-forestry materials for soil conservation.
FAQs:
1. What is soil erosion?
Soil erosion is the process of removal or wearing away of the topsoil by agents like wind, water, and glaciers.
2. What are the main causes of soil erosion?
The key causes include deforestation, overgrazing, poor farming practices, climate change, and steep slopes.
3. What are the different types of soil erosion?
The major types include sheet erosion, rill erosion, gully erosion, wind erosion, and splash erosion.
4. How does soil erosion affect agriculture?
Soil erosion reduces soil fertility, decreases crop yields, and leads to land degradation, making farming unsustainable.
5. What are the best ways to prevent soil erosion?
Some effective methods include planting vegetation, contour farming, terracing, mulching, and using windbreaks.
6. Which areas in East Africa are most affected by soil erosion?
Regions such as Karamoja (Uganda), Turkana (Kenya), and Dodoma (Tanzania) are highly affected due to steep slopes and low vegetation cover.
7. How does climate influence soil erosion?
Heavy rainfall accelerates water erosion, while dry, windy conditions in arid areas increase wind erosion.
