It is generally accepted that sulphur is an essential nutrient for all crops but there is still some confusion over the best time to apply sulphur on cereals.
To decide on the ideal timing to apply sulphur it is necessary to consider how this nutrient behaves in the soil as well as in the plant.
Sulphur is taken up and used by plants in the sulphate form, which like nitrate is very mobile in the soil and will be readily leached. Conversely, sulphur is immobile within the plant so unlike nitrogen, cannot be redistributed from older leaves to the growing points when needed as the season progresses. This is clearly demonstrated by the fact that sulphur deficiency first appears in the youngest leaves.
There is little point in applying all of a crops sulphur requirement in one application early in the season as this simply will not be available when needed by the crop later in the season.
Apply sulphur ‘little and often' together with nitrogen
Trials also consistently support applying sulphur ‘little and often’ together with nitrogen though the season rather than ‘all at once’.
Sulphur is needed by plants, together with nitrogen as a building block for proteins. The ratio of nitrogen to sulphur in most proteins is approximately 12 to 1, except in brassicas where the ratio is nearer 5 to 1.
Since N and S are both required in proportion it makes sense to apply both nutrients at the same time throughout the season. This is exactly when the plant requires these nutrients
Finally there is no point in undoing all the good decisions made above by choosing a poor blended product which segregates during handling and application leading to an uneven application of nutrients to the crop. It is also worth avoiding low bulk density fertiliser which may not capable of being spread evenly over the entire working bout widths, especially if conditions are not ideal. To avoid this choose a compound fertiliser such as Yara Bela Axan and YaraBela Sulphan which contain both nitrogen and sulphur in every granule so eliminating segregation and allowing an even application of all nutrients.
The following compound fertilisers are recommended for all crops and supply a combination of nitrogen and sulphur (N+S) in appropriate ratios to allow the ideal timing for application of both nutrients.
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