A Mulching as a form of no-till farming is a good method of mitigating soil erosion and generating organic manure. PHOTO/MICHAEL J SSALI
The business of crop production involves a lot of activities carried out by the farmer with a view to maximise harvests and profits. However, labour and inputs costs must be put into consideration so that when the crops are harvested and sold, the farmer makes reasonable profit.
Some people are now resorting to cheaper and more soil-health sustaining farming practices in order to increase yields and profits. One such practice is no-till farming.
According to an article posted on the online newsletter “Genetic Literacy Project” (GLP) on December 18, 2024, the world is increasingly looking for sustainable solutions in agriculture and no-till farming has gained attention as a viable way to preserve soil health to reduce erosion, and to improve farm productivity. No-till farming is described as a method where the soil is left undisturbed by avoiding traditional plowing or tillage, which can disrupt soil structure, lead to erosion and contribute to loss of organic matter.
Conserving the soils
Dr Eseri Nankya, a soil scientist working under National Agricultural Research Organisation (Naro), says no-till farming is a good way of conserving the soil.
“It minimises soil disturbance, the risk of erosion by wind and water, and exposure of soil to hot temperature and moisture loss,” she said. She advises farmers to use what she refers to as ripper planters, the tools that make small holes in the ground into which the seeds can be planted. She discourages repeated plowing of the soil in what is traditionally known as seed bed preparation.
“The ripper is used to make small holes on the ground into which seeds are planted without disturbing most of the soil surface in the garden,” she said during a phone conversation with Seeds of Gold. “In some cases, the farmer may use field knives to make small holes into which the seeds are planted. There is very limited disturbance of the soil and hardly any chance for the soil to get washed away when it rains or to be blown away.”
Organic matter
She strongly advises farmers to mitigate weed growth by covering the ground with organic matter such as leaves or grass, or crop residues in what is known as mulching. The organic material covers the soil and preserves moisture, as well as protects the soil from rain and wind, which would drive the soil away. The mulch also minimises weed growth. In Buganda, mulching was practiced in banana plantations using banana leaves and banana stems. Any weeds that managed to emerge were manually uprooted and heaped on what was known as kibibi where they dried up and gradually became manure.
“Some people slash the weeds instead of using hand tools such as hoes. Seed bed preparation carried out with heavy machines such as tractors also has the risk of facilitating soil erosion,” Dr Nankyasaid.
She added that any form of weed control that involves scratching the ground or digging carries the risk of resulting in soil erosion. She also recommends well guided usage of herbicides, which actually destroys the weeds leaving the soil surface intact. Farmers have to understand that over-cultivation of a garden often results in soil erosion, especially if the field is located on a slope.
Dr Nankya, however, said once in a while, after a few years, it is good for the farmer to loosen up the soil for the rain water to infiltrate it and to facilitate underground aeration. “In many cases, when the soil surface becomes too hard, rainfall reception is impeded and there is no soil air circulation, which may not be good for plant root growth and development, resulting in low crop yields.”
When grass or any other organic material is used to cover the soil, it decomposes after some time and becomes manure, which is crucial for soil health. The Genetic Literacy Project article states: “Organic matter improves soil structure, enhances water retention and provides a habitat for beneficial organisms such as earthworms and microbes. These organisms play a vital role in nutrient cycling, breaking down organic matter into nutrients that crops can absorb.”
Enhancing the soil’s ability to retain moisture
It further states that no-till farming significantly enhances the soil’s ability to retain moisture. The presence of mulch on the soil surface reduces evaporation and helps maintain a consistent level of moisture in the soil. “By conserving water, no-till farming makes agricultural systems more resilient to drought conditions,” the article says.
“Additionally, improved soil structure in no-till systems such as mulching allows for better infiltration of rainwater. Instead of water running off the surface, it can penetrate the soil and recharge groundwater supplies. This not only supports healthier crop growth but also contributes to better water management at the landscape level.”
The other advantage of no-till farming, according to the article, is that it is cheaper and therefore profitable because it does not require much labour or fuel. Normal seed bed preparation involves hired labour or diesel to operate machines such as the tractor. Yet fossil fuel is the source of a greenhouse gas (CO2) that is one of those responsible for climate change.
Another advantage of no-till farming according to the GLP article is enhanced carbon sequestration. It says, “When soil is tilled, organic matter is exposed to air, which accelerates the decomposition process and leads to the release of carbon dioxide into the atmosphere. No-till farming minimises this disturbance, allowing organic matter to accumulate and sequester carbon in the soil. By storing carbon, no-till farming can help mitigate climate change and reduce the overall carbon footprint of agriculture.”
Another significant benefit of no-till farming mentioned in the GLP article is the promotion of biodiversity within the soil.
“By avoiding disturbance, the soil becomes a more hospitable environment for a wide range of organisms, including fungi, bacteria, and insects. These organisms contribute to a healthy soil ecosystem by breaking down organic material, cycling nutrients, and improving soil structure. The presence of diverse microbial communities is essential for nutrient availability, plant health, and disease resistance.”
Challenges
As Dr Nankya pointed out, no-till farming has challenges. One of them is management of weeds which has forced many farmers to resort to herbicides.
Yet the problem with dependence on chemicals is contamination of water systems, environment problems and the chemicals’ impact on non-target plant species. Some no-till farmers have resorted to planting cover crops such as mucuna or applying mechanical methods like slashing and mowing.
Pest control can be a challenge since no-till farming permits using crop residues to act as mulching material. Farmers are advised to practice crop rotation to confuse the pests and to disrupt their lifecycles. The use of improved seeds and planting of pest resistant crop varieties can also be preventive.
To realise the benefits of no-till farming does take time and its application certainly requires some specialised equipment, such as precision agriculture tools, which many of our ordinary farmers are not even familiar with. It may also require further training for our agricultural services extension officers.
No-till farming is now seen as the new hope in the wake of the challenges facing modern agriculture given its ability to promote soil health, sequester carbon, reduce erosion and improve soil water retention.
