By John Ssekamwa
Achieving high maize yields requires more than favourable weather and good seed—it depends on precise nutrient management, proper timing and sound agronomic practices, according to a senior agronomist at Yara Uganda.
John Ssekamwa says maize productivity is largely determined by how well farmers align crop nutrition with the plant’s growth stages, ensuring consistent nutrient supply from early development through to grain filling.
“High-yield maize is not achieved by chance. It is the result of aligning the crop’s biology with the right nutrition, the right timing, and sound field management,” he said.
Ssekamwa explains that the foundation of maize yield begins with strong root development and early crop vigour, which enable the plant to efficiently absorb nutrients and water.
Maize yield is mainly influenced by the number of kernels formed on each cob and how well those kernels are filled. This process depends on maintaining a healthy leaf canopy and uninterrupted nutrient availability throughout the growing cycle.
Different nutrients play distinct roles. Nitrogen supports vegetative growth and grain formation, phosphorus is critical for root development, while potassium improves water regulation and grain filling. Other nutrients such as magnesium, sulphur, calcium and zinc are equally important for overall plant health.
A deficiency in any one of these nutrients can significantly reduce yield potential.
The timing of fertiliser application is equally important. Nutrient uptake peaks during rapid growth stages, meaning farmers must anticipate crop needs rather than respond after deficiencies appear.
Experts recommend applying fertilisers in stages to ensure a steady supply of nutrients, improving efficiency and reducing losses.
Soil testing is central to this approach, as it helps farmers understand nutrient levels, identify deficiencies and address soil conditions such as acidity that may limit nutrient uptake.
Ssekamwa notes that modern maize farming is increasingly adopting data-driven approaches, where soil and plant analysis guide fertiliser decisions.
He says balanced nutrition, particularly the use of key nutrients such as phosphorus and zinc during early growth stages, can significantly improve crop establishment and uniformity—factors that ultimately influence yield.
When deficiencies occur, timely intervention is critical to prevent irreversible yield losses.
For farmers, a successful maize production strategy should begin with soil testing, followed by balanced fertiliser application at planting, and supplemented with top-dressing and foliar feeding during peak growth stages.
Attention should also be given to soil pH, as highly acidic soils can limit nutrient availability and root performance.
“A pale or slow-growing crop is not always due to lack of fertiliser. It may indicate poor timing, wrong nutrient application or soil-related constraints,” Ssekamwa noted.
As farmers seek to increase productivity, experts say adopting precision agriculture practices—combining balanced nutrition, proper timing and targeted interventions—will be key to improving yields.
“The science of high-yield maize is ultimately the science of precision,” Ssekamwa said, adding that matching nutrient supply with crop demand throughout the growing cycle is essential for consistent performance.
