Fertilizing Wheat with Polysulphate

Main features

  • Multi-nutrient fertilizer: sulphur, potassium, magnesium and calcium in sulphate form
  • Natural mineral (polyhalite) with single crystal structure
  • Fully soluble, with all nutrients available for plant uptake
  • Low chloride, neutral pH, very low salinity index
  • Good and uniform spreadability in the field, up to at least 36 m
  • Completely natural, low carbon footprint, approved for organic agriculture

Functions of S, K, Mg and Ca in wheat crop

  • Sulphur is an essential constituent of proteins: S is required for the synthesis of three of the necessary amino acids
  • Potassium secures yield and quality: transport of sugars, stomata control, cofactor of many enzymes, reduces susceptibility to plant diseases
  • Magnesium for high photosynthesis: central part of chlorophyll molecule
  • Calcium for strong and healthy crop: a major building block in cell walls, and reduces susceptibility to diseases

Sulphur guide recommendations based on N application rates

Nitrogen rate Sulphur recommendation guide
kg N/ha kg SO3/ha kg S/ha
100 25 10
150 38 15
200 50 20
250 63 25


Nutrient offtake (removal) by wheat crop

Nutrient Offtakes (kg/t) Offtakes (kg/ha)
  grain straw total grain
5 t/ha
straw
2.5 t/ha
total grain
8 t/ha
straw
4 t/ha
total
K2O 5.0 12.5 17.5 25 30 55 40 50 90
K 4.1 10.3 14.4 21 21 42 33 41 74
SO3 3.4 1.3 4.7 17 3 20 27 5 32
S 1.4 0.5 1.9 7 1 8 11 2 13
MgO 1.3 0.8 2.1 4 2 8 10 3 13
Mg 0.8 0.2 1.3 4 1 5 6 2 8
CaO 0.6 1.9 2.5 3 5 8 5 7 12
Ca 0.4 1.3 1.7 2 3 5 4 5 9

Source: UNIFA

Practical guideline for wheat fertilization with Polysulphate

  • One Polysulphate application will supply all the sulphate needed by the wheat crop
  • Sulphur is needed to balance the nitrogen applied so that complete proteins can be produced. Protein content is an important aspect of wheat grain quality
  • 100 kg Polysulphate is generally a suitable dressing for wheat, supplying all of the sulphur and calcium needed, and 50% or more of the potash and magnesium removed in the grain
  • Ensure sufficient potash is applied when straw is removed from the field
  • Apply Polysulphate in early spring, as growth starts in winter wheat – usually at the early tillering stage
  • For spring wheat apply Polysulphate in the seedbed at sowing

Nutrients supplied by Polysulphate at the recommended dose (100 kg/ha) to wheat crop at 6 t/ha grain yield

Nutrients supplied by Polysulphate at the recommended dose to wheat crop at 6 t/ha grain yield

Expected benefits

  • Higher yield
  • Better quality of grain proteins
  • Improved baking quality
  • Increased nitrogen use efficiency

 

Wheat Fertilization with Polysulphate