95% of the food that feeds the world’s population comes from the soil, where plants get 15 of the 18 chemical elements needed for plant growth, but soils continue to be degraded world over.
According to the Uganda Bureau of Statistics Annual Agricultural Survey 2018, soil fertility has declined due to land degradation, soil erosion and demand for the establishment of homesteads.
The situation has been made worse by reports from the Ministry of Agriculture, indicating that fertilizer use that could enhance soil fertility remains low at 0.23 -1.5 kg per hectare, far below the average of 8 kg per hectare as per the Abuja Declaration in Africa.
Additional information from fertilizer manufacturers such as SR Kuku, indicates that despite the importance of the soil, its depletion rate is alarming.
They attribute the depletion to over-reliance on chemical fertilizers that have increased the acidity of soil further rendering it less productive.
Their assertion has been further backed up by soil scientists from the National Agriculture Research Laboratories (NaRL) Kawanda, who adds that Ugandan soil has low levels of nitrogen and phosphorus which are key for plant growth.
According to Dr Crammer Kaizi Kayuki, a soil scientist, from NaRL, the low levels of soil nutrients are due to soil erosion, deforestation among others.
“Despite the decline in soil fertility, Ugandans are reluctant to apply fertilizers and that is why Uganda’s soils lose 21kg of Nitrogen, 8 kgs of phosphorus and 43 kgs of potassium per hectare per year,” he added.
Suggested solutions
That is why Ravi Sankar, the Production Manager and Senior Agronomist at SR Kuku is calling for the integration of organic matter into the soil to enhance its fertility.
“Organic matter is a critical factor in the soil because it maintains the soil structure which enhances water retention, supporting microbial activity, and improving nutrient availability,” Sankar explained.
Organic matter consists of the living organisms within the soil, along with plant and animal residues in various stages of decomposition. It also includes the substances produced by plant roots and other soil organisms.
The advantage of organic matter according to Sankar is that they quickly boost production while excessive use of chemical inputs leads to soil hardening, and reduced microbial activity (processes and biological functions carried out by microorganisms, such as bacteria and fungi, in a specific environment, like soil,) and increased leaching (a process where water moves downward through the soil profile, carrying dissolved nutrients and potentially contaminants with it) of essential nutrients, making farmlands less productive over time.
“Scientific research has demonstrated that the best approach to fertilization is a balanced one, combining organic matter with essential mineral nutrients. Organic fertilizers restore soil fertility by improving biological activity and soil structure, while mineral nutrients ensure immediate plant needs are met. This dual approach to fertilization ensures that both soil health and crop productivity are sustained in the long run,” he added.
Although stakeholders in the agriculture sector are now pushing for the use of organic fertilizers, some scientists argue that this may not be sustainable. This is because of the limited production of organic fertilizers on the market.
To make sure that organic fertilizers are available and accessible, SR Kuku is pioneering the production of high-quality organic fertilizers designed to restore soil fertility, improve yields, and support eco-friendly farming.
Some of the advantages of applying organic fertilizers to the soil are that they improve soil fertility, texture and water retention in the soil, which can be used during dry days.
Organic matter also promotes natural nitrogen fixation and biological activity, ensures steady supply of raw materials to the soil, promotes soil regeneration and prevents useful chemical and nutrient loss by trapping running water, hence preventing soil erosion, according to SR Kuku.
Other organic fertilizer products on the market that farmers can look out for include blended fertilizers from Grain Pulse, and more recently organic fertilizers.
Dr Hillary Rugema, the head of agronomy and advisory at Grain Pulse, said apart from producing blended fertilizers, they have gone into the production of organic fertilizers using chicken dung and water including black soldier fly.
