Ask your Agronomist: Use manure and mineral fertiliser for best results

A farmer attends to her maize crops. Manure provides organic matter in the soil and has an important role to play in crop production. FILE | NATION MEDIA GROUP

What you need to know:

  • Manure provides organic matter in the soil and has an important role to play in crop production.
  • Organic matter has a negative charge, which means it helps to absorb nutrients and make them available to the crop.
  • Fertilisers, on the other hand, provide plant nutrients in a concentrated form, availed in granules/ prills or other formulations for ease of application over a wider area.
  • This allows for the delivery of the nutrients in amounts as demanded by the crops, and the application can be timed to coincide with periods of peak demand by the crop to ensure best uptake and productivity.

Q: I am a farmer growing maize and vegetables in western Kenya.

I want to know if it is necessary for me to buy fertilisers in the shop or to only use manure from my cows.

Samuel

Optimum crop production requires that a farmer critically looks at the nutrition programme that they adopt for whatever crop they grow.

So, whether you grow maize, vegetables or any other crop, understanding the nutritional needs of the crop, and supplying the nutrients in a plant-available form, in the right amounts and at the right time, is the key to success.

Mineral fertilisers and indeed organic manure have the potential to supply needed nutrients.

But lets look at the potential for each:

Organic manure

Manure provides organic matter in the soil and has an important role to play in crop production.

It helps to improve soil buffering capacity and soil structure, which leads to better soil aeration and drainage, improving root development of the crops.

Organic matter has a negative charge, which means it helps to absorb nutrients and make them available to the crop.

However, manure itself depending on the source – whether cow, pig, goat or chicken, will have only a limited amount of nutrients, averaging less than 8kg of N, P and K per tonne.

So, to adequately supply a maize crop that need more than 80kg of N per ha, a farmer would need more than 10 tonnes of manure.

This may not be readily available and is quite expensive for the farmer.

Mineral fertilisers

Fertilisers, on the other hand, provide plant nutrients in a concentrated form, availed in granules/ prills or other formulations for ease of application over a wider area.

This allows for the delivery of the nutrients in amounts as demanded by the crops, and the application can be timed to coincide with periods of peak demand by the crop to ensure best uptake and productivity.

Way forward

Given the very important benefits of organic matter, we do recommend that farmers use manure whenever they have it as much as possible, but clearly it will not satisfy the nutrient needs of the crop hence mineral fertilisers will also be required.

Therefore, for best results apply both fertilisers and other organic sources that you may have.

For crop-specific fertiliser recommendations, please consult your Yara Agronomist near you or the Yara-accredited stockists and distributors in your area.

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Vitalis Wafula
Yara East Africa Regional Agronomist
Contact us on: 0726596050
or 0724255370.