Today as the world experiences crises associated with climate change and over population in some places, farmers are forced to cultivate the same piece of land repeatedly, which in turn leads to soil erosion and depletion.
To overcome the resulting land infertility and low productivity, farmers are increasingly looking to both organic and synthetic fertiliser.
Over cultivation of the same piece of land and soil erosion contributed to soil depletion, which has prompted farmers in Uganda resorting to the use of fertilisers to boost crop growth.
There are many fertilisers, which are applied at different stages in a crop’s lifespan in the garden.
The stages when farmers can apply fertiliser include the planting stage, knee height, flowering stage with different mineral composition.
In the case of maize for example, Uganda farmers use different modes of fertiliser application such as fertigation, foliar spray on leaves and soil as a drench, top dressing, side dressing, broadcasting and ring placement.
The common fertilisers available in Uganda and East Africa at large include NPK, DAP, MOP, UREA, CAN triple sulphate ammonia.
These are available in both liquid and granular form with different mineral rations depending on the user and producers’ preference.
From interaction with Luke Ssenyonga, a senior agro-dealer in Hoima district, maize farmers face challenges identifying the right fertilisers to use at a given stage of crop growth.
According to him, farmers are untutored when it comes to interpreting manufacturer prescriptions and are shy to ask the responsible parties for assistance.
When it comes to fertiliser application different stages of crop growth and each stage requires unique handling. Such handling depends on stages in plant growth.
Planting
At this stage we apply a phosphate rich fertiliser such as DAP di-ammonium phosphate, NPK nitrogen, phosphorus and potassium rich combination.
All these fertiliser combinations are good for planting as they contain element phosphorus responsible for root development. Root development is an important start in a plants lifecycle.
A well-developed root system will set the foundation for a big cob during harvest which every farmer needs.
Phosphate fertilisers also helps in balancing the greenish colours on crop leaves which helps in absorption of sunlight responsible for photosynthesis.
The recommended application rate is 10grams equivalent to one bottle top of Ugandan mineral water.
Here a farmer scoops a bottle top full of fertiliser and pours it into a well-prepared hole then covers it with light soil.
After the normal practice of putting the seed in the hole with fertiliser, the farmer can wait for germination. The mode off application is called basal application.
Knee height
At this stage a nitrogenous rich fertiliser combination is highly recommended since it maintains the greenish colour on the crop leave scientifically known as chlorophyll.
Chlorophyll is responsible for photosynthesis. Photosynthesis is the process by which a crop manufactures its own food.
For any fertiliser combination nitrogen ratio should at least be higher than other elements. Urea is among the best fertiliser rich combination required by a maize crop at knee height as it contains high ratios of nitrogen.
Other fertilisers combinations available in Uganda include NPK, CAN, DAP as they contain nitrates with different trace elements.
In Uganda they are sold in different brand names from different manufacturers and distributors such as Kayosh, panda power, grain pulse, clear green, super green. Aminocop, super grow, among others.
For granular fertiliser top dressing is the best mode of application. At this stage where a 10grams of fertiliser equivalent to one full bottle top of Ugandan mineral water is applied on soil one centimetre away from the crop to prevent scotching.
Foliar fertilisers are applied via foliar sprays. For example, super grow is applied after mixing 20mls into a 20-litre of water which is then sprayed onto a crop in mist form using a knapsack.
Note that it’s advisable to mix a sticker into a mixture of water and super grow before spraying onto the crop to give excellent fertiliser penetration and also reduce on fertiliser wastage as it attaches the fertiliser firmly on the maize leaves.
Flowering stage
This is the most neglected stage in maize farming as most farmers think adding fertiliser is a wastage.
Yet maize needs well balanced soil nutrients responsible for producing pollen grain required in fertilization.
A well-balanced soil nutrient with all trace elements increases flowering, proper grain formation, reduces fungal diseases, as a plant can fight against them hence a healthier crop.
Fertiliser with trace elements like baron, mulbidium, iron, zinc, copper are applied to the crop through folia sprays, since they can easily be used by the flowering plant via the leaves.
The common folia fertiliser available in Agro-shops in Uganda with these trace elements essential for flowering include veg-max, kara, easygro fruit and flower.
The mode of application is via foliar sprays which involve direct spraying of a well-mixed fertiliser in water using a knapsack sprayer.
These fertilisers are mixed in water with different ratios as they differ in strength such as vegmax needs 5 millitres into 20-litres of water, kara 60mls to 20-liters of water.
The ration for easygro fruit and flower is 30g to 20 litres of water. Again 30g equivalent to 3 tablespoons.
The Author is a Researcher, Senior Agricultural Extension Officer, Agribusiness Consultant and CEO at Royal Agro-Input suppliers Buhimba Shop in Kikuube district.
