Because coffee trees produce a high biomass and high economic yield every year, their nutrient requirements are also very high. They need heavy fertilization with a well-balanced nutrient supply to maintain high, stable, and sustainable yields.
Coffee requires large amounts of macro-, secondary-, and micro-nutrients. For every metric ton of green coffee beans produced, the crop removes about 26.7 kg of nitrogen (N), 2.7 kg of phosphorus (P), 28 kg of potassium (K), 3.3 kg of calcium (Ca), 3.3 kg of magnesium (Mg), 4 kg of sulfur (S), plus significant quantities of trace elements. This shows that coffee needs especially high levels of N and K (roughly ten times the demand for P) and also has very high requirements for the secondary nutrients Ca, Mg, and S (even higher than for P).
Young coffee trees in the establishment phase, when root systems are still weak, need an abundant supply of phosphorus to stimulate root growth.
Proper fertilization and care during the flowering and fruit-set period not only improve yields but also reduce harvesting labor and enhance the quality of the beans. Uniform flowering leads to more synchronized ripening, which helps create the distinctive aroma and flavor of high-quality coffee.
Before this stage—right after the previous harvest—growers should fertilize while pruning and reshaping the canopy. Pruning is an important technical step that prepares the tree for flowering and fruiting. At this time, apply organic fertilizer, phosphate fertilizer, and an appropriate amount of NPK to “recharge” both the soil and the plant, rejuvenating the root system and fruit-bearing branches. Choose NPK formulations designed for the dry season and follow the manufacturer’s recommended rates. In addition, supply secondary nutrients such as dolomite, serpentine, or agricultural lime at about 500 kg/ha.
During flowering and fruit set, supplement with nitrogen (N) and potassium (K) to nourish the developing fruit, and provide the micronutrients boron (B) and zinc (Zn) to improve pollination and fruit set.
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If irrigation is not available, avoid applying granular fertilizers because soil moisture is needed for them to work effectively.
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If irrigation is available, foliar sprays of a fertilizer with an NPK ratio around 30-10-10 plus trace elements (especially boron) can be used, or add extra B to enhance pollination and fruit set.
Using coffee-specific fertilizers tailored for the early-season flowering and fruit-formation stage will best meet the crop’s nutritional needs.