This archive report was first published on 14 August 2019.
Kenyan farmers are facing a significant challenge in achieving optimal maize yields, with many recording low yields of between nine to 11 bags per acre. This is a far cry from the target of 30 to 40 bags in most regions.
According to experts, poor farming practices are a major contributor to this problem. One key area of concern is the application of fertilizers, particularly nitrogen.
Top-dressing, which involves applying nitrogen in granular fertilizer form to crops, is a crucial practice that can boost yields. However, it must be done at the correct crop growth stage and at the right rate.
Urea or CAN, a source of nitrogen, works best when applied when the maize is knee-high, around 18 inches tall. This is because the plant's root ball will have grown to around nine inches of depth under the soil, allowing the fertilizer to be absorbed effectively.
However, urea should only be used when rain is guaranteed, as it will hydrolyse and be lost as gases to the atmosphere if not dissolved in the soil within 24-48 hours. In uncertain weather conditions, CAN is a better option, despite being more expensive.
It's also essential to note that nitrogen and other nutrients are not taken up at a constant rate through the crop's life. Many farmers apply fertilizers too early, around the three to four leaf stage, which is too early for the nitrogen requirement of the plant.
Experts recommend weeding between the rows of maize until the plants achieve their natural canopy, which will then suppress further growth of weeds. Weeding during dry spells can have a negative effect, removing soil moisture, so it's best to do it when the rain is around.
Additionally, weeding before the plants flower is crucial to prevent them from seeding and regrowing. Weeding by hand or mechanically is possible, but the latter must be done with GPS guidance to avoid uprooting the planted maize.
Inter-cropping maize with beans or other leguminous crops can provide some benefits, such as reducing crop failure risk and providing a cover crop. However, in the long-term, crop rotation is a more effective way to achieve a good natural soil nutrient balance and maximize yields.
Robley, the managing director of FMD, the Massey Ferguson distributor for East Africa, emphasizes the importance of embracing good farming practices to achieve optimal maize yields.
