In Summary
  • Farmers can put compost or manure in the holes to raise the soil fertility and water-holding capacity, and then sow maize or beans, writes Lominda Afedraru.
  • Organic matter is the decomposed product or by-product of animals and plants that when applied to the soil is converted into humus.The most common locally available organic fertilisers are cattle manure, poultry manure compost, pig manure, sawdust, grass and leaf litter.

Land degradation can either be a natural or man-made process which impairs the capacity of the land to function.
Soils are affected in the process when acidification, sedimentation, contamination and erosion, occurs.
Land degradation lowers the soil fertility status due to the removal of change in the chemical and physical properties in the top soil and organic matter.
The situation in Uganda indicates that soil degradation is on the increase coupled with farmers over tilling the land minus replenishing it to cause fertility.
As such there is concerted effort by different players including Naro, Ministry of agriculture and Agri pro focus under an initiative Soil Cares aiming to bring on board farmers in a bid to improve their soil fertility.
In a recent stakeholders meeting in Kampala by Agri Pro Focus to discuss the way forward on how to help farmers adopt practices to improve on their soil fertility, Seeds of Gold caught up with Robert Muzira Research Officer at Mbarara Zonal Agricultural Research Development Institute and below are the excepts.

Soil conservation
It is important for farmers to practice terracing by constructing barriers along the contours of the land with the purpose of preventing the rapid flow of water down the slope.
Cultivation along steep slopes may cause severe soil erosion. The ideal way is to cultivate shallow rooted crops such as vegetables on terraces.
“Before planting any crop it is important to carry out soil sampling and testing to identify the actual nutrient. Do not apply fertiliser before testing the soil nutrient,” says Muzira.

Vegetative barriers
Vegetative barriers made up of one or more rows of trees or shrubs planted so as to provide shelter from the wind. It is also used to protect the soil from erosion and act as wind breakers.

Contour cultivation
Contour cultivation is when crops are planted along the contour lines. This helps to prevent soil erosion on sloping land. Farmers can cultivate crops such as sweet potato, cassava, pineapple, banana and fruit trees.

Strip cropping
Strip cropping is practiced on steep slopes involving two crops. One of the two crops is preferably a fruit tree with well-developed root system and the other a shallow rooted crop such as a vegetable.
Crops are cultivated in alternate strips where the speed of flowing water is constantly reduced by the alternate strips of crops.

Manure
Farmers are advised to process manure obtained from fermentation of feces and littre of animals.
There are different types of manures used locally. Poultry manure is high in nitrogen and good for leafy vegetables. There is also green manure obtained from any crop grown to increase soil fertility. They are plants that can provide nitrogen to the soil through their ability to fix nitrogen.

Inorganic fertilisers
Application of inorganic fertilisers processed from salt containing one or several nutrients required by plants is another means of containing soil fertility.
The correct timing and quantity of fertilisers is important so that the crop grows at the normal rate.
It should be used depending on the type of soil. Alkaline forming fertilizers should be used in red soils and acidic sandy soils.

Mulching
Mulching is important to protect the plant and the soil. It provides a source of plant nutrients and acts as a weed suppression agent.
It also maintains the optimal soil moisture level, reduces soil evaporation and protects plant root from extreme temperature.
In the case of the tree crops, it is recommended that the mulch is placed about 30cm away from the base of the trunk.
Mulch has to be applied before the rainy season and the mulch layer should not be too thick as it will be difficult for the germinating plant to reach the surface.

Irrigation
Irrigation is necessary for plant life and growth. The aim is to maintain an adequate soil moisture level around the seedlings and seeds of plants. Open ended horse, Watering can, Overhead sprinklers, Mini-sprinklers and drip irrigation system are recommended.

Nutrient management
Integrated nutrient management is one of the modern approaches of farming in which inorganic fertilisers are used to a minimum.
The practice involves using organic fertilisers instead of synthetic fertilisers. This is aimed at achieving the balance between the conservation of nutrients in the soil and the uptake of nutrients by the crop.

Intercropping
Through intercropping the rooting systems of the various crops use different elements in the soil profile, ensuring better nutrient uptake.
Whilst practicing intercropping, vegetable of the same family, such as eggplant, chilli, sweet pepper and tomato should be avoided as they are affected by the same pests and diseases. There should be a mixture of leguminous plants such as beans with leafy and fruit vegetables.
Crop rotation
Crop rotation makes use of residual nutrients, pests and diseases are also controlled and it helps to reduce soil erosion as it provides soil cover. Improve soil fertility with the decomposition of leave litter and farmers should avoid rotating plants from the same family.
Drains

Drains are dug-up structures for the disposal of excess surface water during and after rainfall. The drains should be reticulated and be linked so as to dispose of the excess water from the entire cultivated area.
Organic matter
Organic matter is the decomposed product or by-product of animals and plants that when applied to the soil is converted into humus.The most common locally available organic fertilisers are cattle manure, poultry manure compost, pig manure, sawdust, grass and leaf litter.