Fertilizing Coffee with Polysulphate

Fertilizing Coffee with Polysulphate

Main features of Polysulphate fertilizer

  • Ideal multinutrient fertilizer with 48% SO3 plus potassium (14% K2O), magnesium (6% MgO) and calcium (17% CaO), all in sulphate form.
  • Prolonged nutrient release pattern that reduces risk of nutrient leaching.
  • Fully soluble, with all nutrients available for plant uptake during the growth period.
  • Excellent spreading haracteristics; spreads evenly and accurately in the field up to 36 m.
  • Low chloride, very low salinity index, neutral pH, no liming effect.
  • Natural mined mineral (polyhalite) approved for organic agriculture.
  • UK produced fertilizer with a low carbon footprint.

Functions of S, K, Mg and Ca in coffee crops

  • Sulphur is an essential constituent necessary for the synthesis of three amino acids and multiple enzymes. Necessary for high nitrogen use efficiency.
  • Potassium secures yield and quality, transport of sugars, stomatal control and is a co-factor of many enzymes. It reduces susceptibility to plant diseases and the impact of drought, and is essential for efficient use of nitrogen. Improves color, quality and resistance of the coffee beans.
  • Magnesium is fundamental for photosynthesis, being a central part of the chlorophyll molecule. Increases sugar formation.
  • Calcium is required for strong and healthy crops; it is a major building block in cell walls and reduces susceptibility to diseases and stress conditions.

Practical guidelines for fertilizing coffee with Polysulphate

  • Low-chloride Polysulphate is a sulphate-based source of water soluble potassium, magnesium and calcium, supplying all of the sulphur, magnesium and calcium needed, and a significant proportion of the potash removed at
    harvest without affecting the soil pH.
  • Coffee beans remove very large amounts of potassium at harvest and the proportion not supplied by Polysulphate can be applied as muriate of potash; both sources must be applied during the rainy periods to allow the gradual nutrients release from fertilizers, to provide a continuing fresh source to the growing crop, and to increase the four macronutrient uptake by the coffee plantations.
  • Polysulphate can be surface applied as a constituent of a fertilizer blend near the trunk twice or three times a year.
  • 600 kg/ha Polysulphate is generally a suitable dressing for supplying all Ca and S required by any coffee crop and reach maximum productivity.


Estimated nutrient offtakes (removal) by the coffee harvest

Nutrient Offtakes (kg/t of green
coffee beans - tgcb)
Offtakes (kg/ha)
    2 tgcb/ha 3 tgcb/ha 4 tgcb/ha
N 31.0 62.0 93.0 124.0
P2O5 5.2 10.4 15.6 20.8
SO3 3.0 6.0 9.0 12.0
K2O 44.3 88.7 133.0 177.2
MgO 3.8 7.5 11.4 15.2
CaO 6.0 12.0 18.0 24.0

Adapted from Manual Cafetero (2013)

Nutrients supplied by Polysulphate at the recommended dose (600 kg/ha) to coffee crop

Expected benefits

  • Higher yields
  • Improved fruit size and weight
  • Better cup quality
  • More balanced nutrition
  • Increased nitrogen use efficiency

 

Fertilizing Coffee with Polysulphate