Fertilizing Wheat and Barley with Polysulphate

Fertilizing Wheat and Barley with Polysulphate

Main features of Polysulphate fertilizer

  • Ideal sulphur fertilizer with 48% SO3 and additional benefit of potassium (K), magnesium (Mg) and calcium (Ca), all in sulphate form.
  • Reduced risk of sulphate loss through leaching due to prolonged nutrient release pattern.
  • Fully soluble, with all nutrients available for plant uptake during the growth period.
  • Excellent spreading characteristics; spreads evenly and accurately in the field up to 36 m.
  • Low chloride, very low salinity index, neutral pH, no acidifying 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 cereal crops

  • Sulphur is an essential constituent of proteins: it is required for the synthesis of three of the amino acids which make up true proteins.
  • 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 impact of drought and is essential for efficient use of nitrogen.
  • Magnesium is fundamental for photosynthesis, being a central part of chlorophyll molecule, and is key to grain filling.
  • Calcium for strong and healthy crops; it is a major building block in cell walls and reduces susceptibility to diseases.

Sulphur main dressing - guide recommendations

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 winter and spring wheat and barley

Nutrient Offtakes (kg/t) Offtakes (kg/ha)
  Wheat and barley Winter cereals Spring cereals
  grain straw grain
8 t/ha
4 t/ha
total grain
6 t/ha
3 t/ha
winter spring
K2O 5.6 9.5 12.5 45 38 83 34 38 72
K 4.6 7.9 10.4 37 32 69 28 32 60
MgO 2.0 1.2 1.3 16 5 21 12 4 16
Mg 1.2 0.7 0.8 10 3 13 8 2 10
CaO 0.6 1.9 1.9 5 8 13 4 6 10
Ca 0.4 1.4 1.4 4 6 10 3 4 7

Sources: UK Fertilizer Manual, PDA and UNIFA

Practical guidelines for fertilizing cereals with Polysulphate

  • One Polysulphate application will supply all the sulphate needed by cereals.
  • Polysulphate can be applied as a straight or included in a blend as part of a tailored fertilizer program.
  • Sulphur is needed to balance the nitrogen applied so that complete proteins can be produced. Protein content is an important aspect of grain quality.
  • 100 kg/ha Polysulphate is generally a suitable dressing for cereals, supplying all of the sulphur and calcium needed, and a large proportion of the potash and magnesium removed in the grain at harvest.
  • Ensure sufficient potash is applied if straw is removed from the field.
  • Apply Polysulphate in early spring, as growth starts in winter cereals – usually at the early tillering stage.
  • For spring cereals incorporate Polysulphate into the seedbed at sowing.

Nutrients supplied by Polysulphate at the recommended dose (100 kg/ha) to cereal crops at 6-8 t/ha grain yield

Nutrients supplied by Polysulphate at the recommended dose (100 kg/ha) to cereal crops at 6-8 t/ha grain yield

Expected benefits

  • Higher yields
  • Better quality of grain proteins
  • Improved baking, malting and feed quality
  • Increased nitrogen use efficiency


Fertilizing Wheat and Barley with Polysulphate