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
Expected benefits
- Higher yield
- Better quality of grain proteins
- Improved baking quality
- Increased nitrogen use efficiency
Wheat Fertilization with Polysulphate