Fertilizer use
Maize can be produced using either organic or inorganic fertilizers. Organic fertilizers commonly used for maize production include compost or animal manure. Organic manure provides the desired plant nutrients, improves the water retention and the physical condition of the soil.
You can apply well composted farmyard manure at the rate of 4 tons/acre. However, under severe soil fertility deficiencies, apply the manure at the rate of 8 tones/acre. The farmer should apply the manure immediately after the first cultivation and incorporate it into the soil thoroughly on the second cultivation to enable efficient uptake by the crops currently under cultivation.
The farmer can also use different types of inorganic fertilizer at different stages of crop growth. The inorganic fertilizers can be applied as a standalone nutrition treatment or in combination with organic fertilizer. The rates given in this manual are general recommendations for good agricultural practices. However, the farmer needs to conduct soil tests to determine the precise nutrient requirements of their farms and the corresponding optimal rates and best fertilizer types to use. Generally, applying DAP as the basal fertilizer at the rate of 50 kg/acre at planting and CAN at the rate of 92 kg/acre is sufficient for farms with moderate soil fertility levels. In cases of heavy rainfall, split application is more suitable and the final top dressing should be conducted just two weeks before flowering. Fertilizers should be applied on moist soils.
The basal fertilizer should be placed in the hole first, covered with approximately 5 cm of soil depth before placing the seeds. For top dressing, making a circular or parallel furrow of 5 cm in diameter on both sides of the crop, whichever is more practical and faster, fertilizer placed in the furrow of and covered with soil. Placing fertilizer in furrows and covering reduces loss through leaching and volatilization.
Liming
Liming is necessary in acidic fields to help raise the soil pH to neutral or near neutral levels which are optimal for maize production. Naturally, several agricultural farmlands in Kenya are acidic in nature. However, applying lime in maize production fields should only be considered after testing the soil pH of individual farms. The optimal pH for maize production ranges from a pH of 6.0 to 7.0 and therefore lime should only be applied when the farm's pH is below the optimal pH range.
There are several products in the market which you can consider for liming the farmland. Some of the commonly used and effective examples include Calcium oxide and Calcium carbonate presented in the form of limestone rock powder. Further, there are commercially available fertilizers in the market with liming effect and using them in acidic soil has exhibited increased yield output.
These include MEA mavuno, Mavuno basal that are both applied at the recommended rate of 100kg/acre and Mavuno for top dressing which should be applied at the rates of 75kg/acre. Lime should be applied on dry soil, spread evenly, approximately two weeks before planting to provide sufficient room for the lime to react with the soil.
