Most farmers across the country usually treasure land on the foothills of mountainous areas knowing they are fertile and can cause good yields.

These areas include the Kigezi region in Western Uganda and the Rwenzori region in Eastern Uganda.

However much as land on the foot hills are believed to be fertile, there is a challenge of water run offs during rainy season causing soil erosion which depletes much of the soil nutrients becoming a problem in crop yield.

This therefore leads to farmers adopting the necessary technology which includes practicing terracing and contours to conserve the soil health.

Scientists at Kachwekano Zonal Agricultural Research and Development Institute (KaZARDI) in Kabale have improved on the terracing system which works far better in conservation agriculture.

Conservation agriculture

Amos Justus Mutayomba Matungulu, a research scientist at KaZARDI describes Conservation agriculture as a farming approach that emphasizes the preservation of soil health, water retention and biodiversity while promoting sustainable agricultural productivity.

He notes that farmers practicing agriculture in hilly areas are encouraged to adopt conservation agriculture practices which is vital for combating soil degradation, climate change effects to ensure food security.

He says several conservation agriculture techniques have been introduced across different regions, supporting farmers in managing natural resources effectively while increasing productivity. His team has specialised in improving the terracing and contour system to improve farmer yields

Terracing Technology development  

According to Mutayomba his team at Kachwekano Zardi have developed an innovation that integrates a number of technologies to harness and address challenges farmers are faced with concerning soil erosion. This includes contour reserve bends, terraces and agro forestry practices.

How the technology is made

According to Mutayomba farmers in hilly sloppy areas have been practicing terracing and contours before but in rather a rudimentary way

In 2023, the team under a project called BRIGHT funded by the International Fertilizer Development Centre (IFDC) in the USA developed the technology mainly to help farmers in Kigezi and Rwenzori region.

The team identified sites at Kachwekano Zardi research Institute in Kabale, in Kariba village in Rubanda district and in Nyarugono village in Bunyagabu district.

After identifying the sites, the farming community were mobilised to carry out the landscaping together with the scientists in order to determine the category of the ecosystem

The team then established Terraces where they constructed the foundation but maintain the top soil. The next step is to level subsoil gravels, build the upland and lower land, level the terrace, splash back the op soil and establish stable beds.

What is important to consider are the geological factors depending on the soil type, hydrological factors where the level of water draining in the soil is considered as well as the altitude.

This therefore determines which agricultural crop fits in which specific terrace design. A case in point is where the spacing of the terrace levelling for Apples is expected to be 3 meters by 3 meters and for Irish Potatoes in 5 meters by 5 meters.

This technology according to the scientists eliminates flooding and soil erosion and it restores degraded water shade in a period of less than one an half years.

It also restores lost nutrient and assures increase in crop yield because it facilitates regenerative agriculture.

Farmers can also use the water catchment in the water shades for irrigation during dru season.

The second technology which has been tested is contours, where grass bends, shrubs, Agro forests are planted and tree hedges at the slopes to hold running rain water.

Farmers in the Rwenzori and Kigezi region growing assorted crops namely potatoes, climbing beans, apples and banana among others have already adopted the technology.

The scientists are already working another technology which will help in minimising landslides in hilly areas of the country.

The technology called underground water pressure release will control underground water levels rise which ends up causing landslides.

According to Mutayomba, farmers living on hilly slopes end up covering natural paths where water is expected to flow downstream. Once the cover these water paths with soil, it will gradually cause holes and the heavy rains will soften the soil causing landslides.

The technology will create diversion of the ground water allowing the remaining land to dry and stabilize.

The technology involves establishment of structure including vertical trellises, French drains and diversional tunnels to allow water uphill to flow.

Recommended conservation Agriculture Practices

According to Mutayomba as a team of agricultural scientists handling solutions to address soil health for increased yields, farmers are required to observe practices which include minimal soil disturbance referred to as No-Till Farming.

This practice involves reducing or eliminating ploughing to preserve the soil's natural structure and by avoiding soil disturbance, farmers help maintain organic matter, reduce erosion and improve water infiltration.

This technique can also be used during times of drought to preserve soil moisture.

Crop Rotation and Crop Diversification is another method which helps improve soil fertility and reduce pest and disease cycles.

Farmers rotate nutrient-demanding crops such as maize with nitrogen-fixing legumes like beans, groundnuts and soybeans.

In areas such as Kabale and Kisoro in South-western Uganda, where soil erosion and nutrient depletion are major issues, crop rotation has proven to be highly beneficial in restoring soil fertility and increasing yields.

Another practice is mulching which involves covering the soil with organic materials, such as crop residues or leaves, to reduce water loss, suppress weeds and protect the soil from erosion.

This according to the scientists is highly adopted in Mbarara and Bushenyi districts where mulching is used to conserve moisture in banana plantations and other crop fields, contributing to sustained productivity even during dry spells.

The team recommends farers to adopt Agro-forestry which is the integration of trees and shrubs into agricultural landscapes providing benefits of improved soil fertility, erosion control for improved crop yields.

Trees such as Grevillea, acacia and fruit trees are planted alongside crops. In regions like Mount Elgon and the Rwenzori Mountains, agroforestry is promoted to reduce soil erosion on steep slopes and provide additional sources of income through timber and fruit production.

It is recommended for farmers to plant cover crops are grown to protect and enrich the soil during off-seasons.

Leguminous plants such as cowpeas, pigeon peas and clover are commonly used as cover crops to add nitrogen to the soil.

In regions where rainfall is inconsistent, water harvesting techniques such as rainwater collection and the use of small dams are essential for ensuring adequate water supply during dry seasons.

The most applicable method for farmers on slopes of hills and mountains is Contour Farming and Terracing.

Contour farming involves ploughing along the contour lines of slopes to reduce water runoff and soil erosion. This practice is particularly useful in hilly areas, such as Kabale and Mbale where terracing and contour farming help preserve soil fertility and control erosion on steep slopes.

The local communities here benefit from reduced soil loss and better water retention, which significantly improves crop yields.

Traditional types of terracing practiced by farmers

Mutayomba contends that Farmers in the hilly areas of Kabale district practice a sophisticated, traditional form of terracing to manage steep slopes which is essential for reducing soil erosion, conserving water and creating arable land.

This system is characterized by a forward-sloping terrace design, primarily developed through long-term, intensive human effort, commonly referred to as progressive or bench terracing. 

Evolutionary Progressive Terracing:  this is where farmers create terraces over time rather than all at once. They start with a, contour bund or a trash line, which gradually accumulates soil washed down from above, eventually forming a flat bench-like structure.

Contour Hedgerows: This involves planting vegetation, specifically Napier grass across the slope at intervals of roughly 15 meters. These grass strips hold the soil in place and act as a .barrier that builds up soil behind them which becomes stable

Tillage Erosion: The unique shape of the terraces is partly caused by the traditional practice of hand-hoeing while facing uphill, which slowly moves soil downhill over many years to settle against the contour bunds.

Bench Terracing Construction: This practice is where farmers build bench terraces. This involves cutting into the hillside, removing topsoil, levelling the subsoil and then returning the topsoil to the new level surface.

Integrating Complementary Techniques: Terracing is rarely used alone. It is integrated with agroforestry.

The practice has turned steep, otherwise unusable slopes into highly productive, deep-soiled, and sustainable agricultural plots. 

Farmer experience

Nr Charles Byarugaba who comes from Katanga Parish in Kabale district is a progressive potato farmer and seed producer.

He notes that he has been engaged with the scientists in testing the terracing and contour technology which he already implementing of his Irish potato farm.

“The technology works well because the scientists sensitized farmers to follow the spacing of the terrace construction depending on each crop type. The spacing for Irish potato is different from beans, apples and banana,” he notes.

He contends that farmers never observed spacing calculations for various crops when constructing traditional terracing and this did not solve the challenge of soil erosion and water retention to improve soil nutrient.