By Joshua Kato
Experts have identified horticulture as an enterprise that can enhance national productivity, competitiveness and incomes. It has the economic potential on both local and international markets.
All plants can grow naturally if farmers provide the necessary natural ingredients to support the development of natural fungi, scientifically called mycorrhiza.
“Although soil microbes, particularly the root based mycorrhiza fungi, are extremely important, they are taken for granted by farmers and even destroyed by fungicides,” Peter Celestine Byaruhanga, a researcher at Bukalasa says.
This fungus is particularly interconnected and interdependent with plants.
At his research farm in Bukalasa, inside Bukalasa Agricultural College, Luwero district, Byaruhanga, a retired professional agricultural scientist, has nearly every plant, basically for research purposes.
The farm has all common fruit trees, including jackfruits, avocados, guavas, mangoes and sour soup. There are also coffee trees, bananas, maize, beans and rare pulses.
Byaruhanga, who graduated in 1976 from Makerere University, worked as an agriculture officer in Luwero before he retired and started a private farm research business in 1998.
His main focus is using ‘nature’ to practice farming. A mycorrhiza is a symbiotic association between a green plant and fungus.
The plant makes organic molecules by photosynthesis and supplies them to the fungus in the form of sugars or lipids, while the fungus supplies the plant with water and mineral nutrients, such as phosphorus, taken from the soil.
Mycorrhiza are located in the roots of vascular plants. The most common is present in 70% of plant species, including many trees and crop plants such as cereals and legumes.
“If the fungus can access all its needs or requirements, particularly soil, moisture, optimal temperature, and soil carbon, then the plant can also access all its critical needs, including soil nutrients,” Byaruhanga says.
He explains that because of this, the crop will be resilient to potential stress factors, including deadly viruses such as wilts.
Byaruhanga explains that plants are facing a lot of stress due to the low carbon in the soils, since elements of nature, such as useful fungi, have been affected by the use of artificial farm chemicals.
“The fungus on the roots is responsible for linking the plant with the soil,” he says.
He explains that it is responsible for producing hormones, enzymes, and antioxidants that are responsible for crop growth.
Byaruhanga, however, points out that this is a plant growth element that the majority of farmers take for granted. Although it is not easily visible on smaller plants, the fungus can be seen growing on trees.
In natural forests, almost every tree carries this fungus.
He says this explains why uninterrupted natural forests have survived without fertilisation for centuries.
“People may wonder why forests and wild crops survive without fertilisers, but it has everything to do with this fungus,” he says.
Mycorrhizal plants are often more resistant to diseases, such as those caused by microbial soil-borne diseases.
These associations have been found to assist in plant defence both above and below ground. Mycorrhizas have been found to excrete enzymes that are toxic to soil-borne organisms, such as nematodes.
More recent studies have shown that mycorrhizal associations result in a priming effect in plants that essentially acts as a primary immune response.
When this association is formed, a defence response is activated similarly to the response that occurs when the plant is attacked.
“This fungus is responsible for regulating and controlling the retention and slow release of all essential nutrients that the plant needs and, in the process, reducing the risk of nutrient leaching and loss,” he says.
Byaruhanga, however, points out that the use of artificial farm chemicals affects the growth of these useful fungi.
He advises farmers to use organic, bio-fertilisers, chemicals to enhance nature growth and prevention of pests.
What is needed for organic compost
Byaruhanga says farmers can use vegetative materials and farm waste such as tithonia, stovers of maize, soybeans, beans and finger millet, banana peelings, rice and sorghum straws.
One can also use sweet potato vines, cassava or potato peelings, dry and green grass, Mexican sunflowers, animal and poultry wastes, or even kitchen wastes.
How to process organic compost
Byaruhanga uses plastic buckets to process the compost. However, farmers can also dig pits.
- Dig a pit 1.5ft deep by 4x4ft wide and place four poles (6ft long), one for each corner of the pit.
- Chop selected vegetative materials into small pieces and dump them in the pit as the first layer. Sprinkle 10lts of water.
- Add a second layer of dry vegetation of hedge cuttings to about 20cm thick and sprinkle water.
- Add the third layer of animal or poultry waste or slurry, which provides micro-organisms that are essential for decomposition.
- Please sprinkle ash as it contains essential minerals.
- You can then add the fourth layer (about 20cm thick), consisting of green materials from leguminous trees such as Calliandra, Leucaena and Tithonia. Sprinkle a little topsoil up to 5cm thick. The soil contains bacteria which helps in decomposition.
- Repeat the placement of layers as in the steps above, starting with dry vegetation, then animal or poultry waste or slurry, ash, green vegetation and topsoil. Remember to sprinkle water on every layer.
- The final pile should be 1.5–2m high, with vertical sides and a flat top. To complete the pile, cover it with a layer of 10cm thick topsoil. Finally, cover the whole compost pile with dry vegetation (banana leaves) to reduce moisture loss through evaporation.
- Decomposition starts three days after pile formation.
- Drive a long-pointed stick at an angle to check the decomposition. The stick should be left in the pile and only removed once a week. When you pull out the stick from the pile, it should be warm and moist but not wet. This confirms that decomposition is in progress. A cold stick is an indicator of no decomposition.
- Sprinkle 20lts of water on the pile every three days during dry spells. After two–three weeks, turn the pile. Compost is ready after six–nine weeks. Ready compost should have a fresh soil smell and should not contain grass, leaves, or animal or poultry waste.
LEAD PHOTO CAPTION: A compost heap. Farmers can use all forms of kitchen waste and vegetations to make compost for their crops.
