Coffee

and Important Nutrients for high yields

Nitrogen

improves vegetative growth
increases crop bearing capacity
increased bean size

Phosphorous

roots and bearing wood development
early berry maturity
bean density

Potassium

berry development and ripening
mucilage formation
water utilization efficiency

Magnesium

enhances bean colour (blue/green grey colour)
food formation

Zinc

plant hormone
influences leaf size
intensifies flower initiation and formation

Boron

promotes shoot growth
facilitates optimal flowering and fruit setting

Sulphur

enhances aroma of the liquor

Molybdenum

enhances Nitrogen metabolism

Typical Coffee NPK fertilisers are as follows:

NPK 15-5-20+te
NPK 17-17-17
NPK 20-10-10
NPK 22-6-12+S+MgO+Zn+B

Amount of trace elements are adjusted to meet local requirements.

For successful coffee farming, growers need to monitor their plots regularly. If there are visible or anticipated micro-nutrient deficiencies, at least one foliar application is required.

Popular formulations:

NPK 20-20-20 +B+Zn+Cu+Fe+Mn+Mo (Potassium source is Potassium Nitrate and SOP)
NPK 18-18-24+MgO+B+Zn+Cu+Fe+Mn+Mo
NPK 10-5-5+5B+5Zn

Photo: Arabica coffee growing in Ethiopia

A rule of thumb application recommendation is 250 kg/tree of NPK during the season. Normally the first application (125 g/tree) is approx 6 months before flowering and the second application (125 g/tree) is after flowering, when berries start to grow. it is also recommendable to have soil analysis every third year to fine-tune nutrient contents.

In East Africa, another general rule is that you need 1 kg of Nitrogen to be able to grow 10 kg of coffee berries. If your target yield is 2000 kg/ha of berries, you need to apply 200 kg/ha of Nitrogen.

Robusta in Uganda

Flowering Robusta in November

Tailor made robusta NPK 18-5-14+te applied by hand

Robusta coffee berries