July 12, 2021 10:05 am Published by LauraE
supplying sulphur

Supplying Sulphur to your crops

Sulphur is a key component when growing high yielding, healthy crops. Whilst Nitrogen is a growth promoter, Sulphur works as a growth regulator, effectively balancing the manufacture of sugars and proteins in leaf tissue with the demand from these materials throughout the plant. Consequently, Sulphur plays a crucial role in maintaining green leaf area, growth rates and delaying senescence. Low Sulphur levels reduce Nitrogen metabolism, leaf expansion and plant development. The nutrient is very mobile in the soil meaning wet winters and early springs leave low reserves in the soil. Crops need a steady supply throughout rapid growing seasons, so it’s key to apply S each time N is applied.

Steadily Supplying Sulphur to the crop

Sulphur deposition has decreased dramatically throughout the UK over the last 30 years, as a result of the Clean Air Act. Deficiencies of this vital element are now visible in many areas of the UK. Where deposition is less than 10kg/ha/year most crops will benefit from applications of fertiliser containing sulphur.

The Nitroflo Range

Sulphur can be applied alongside Nitrogen, when using the OMEX Nitroflo range of Liquid fertilisers.

liquid fertiliser

The Nitroflo range offers tailored a range of N+S solutions:

Nitroflo 28+S – containing nitrogen and a low level (2.5% S03) of sulphur.
Nitroflo 26+S – containing nitrogen and 5% SO3 sulphur; for top-dressing sulphur responsive crops in the spring during periods of rapid growth and ensuring strong, even growth. The sulphur source is sulphate. The most widely used product in the Nitroflo range.
Nitroflo 24+S – containing nitrogen and a higher level of S (7.5% S03) than Nitroflo 26+S. The sulphur source is sulphate.
Nitroflo 22+S – containing nitrogen and a higher level of S (10% S03) than Nitroflo 24+S. The sulphur source is sulphate.
Nitroflo 20+S – containing a higher level of sulphur (12.5% S03) for deficient areas and crops with a high demand for sulphur, such as oilseed rape. The sulphur source is sulphate.
Nitroflo 15+S – containing an equal amount of nitrogen and sulphur; ideal for first nitrogen application on oilseed rape. The sulphur source is sulphate.


Suspension Fertilisers

Application of Sulphur can also be made using OMEX Suspension Fertilisers.

Suspension Fertiliser application

Suspension Ferilisers offer farmers a bespoke nutritional service, meaning the crop receives exactly what it needs to grow. Using the free soil sampling service OMEX provide, you’re able to gain a true understanding of the Sulphur requirements for the season. Suspension Fertilisers offer tailor made nutrition, and are applied by a contractor service, meaning they’re a useful time management tool.

Foliar Fertilisers

Foliar fertilisers are ideal for offering the crop a boost of nutrition, whether that be maintaining crop health or during times of stress.

Foliar fertilisers bypass limiting soil conditions and prevent nutrient deficiency. They work by targeting specific organs, alleviating stress situations and boost growth during critical stages of plant development.



Sulphomex is used to correct sulphur deficiency, or as part of a programme to prevent sulphur deficiency. It should be used when deficiency is diagnosed or suspected. Refer to individual crop recommendations for timings.


Speak to your local Liquid Fertiliser Expert when deciding which foliar fertiliser product is relevant to your crop.

How much Sulphur to Apply

The continued reduction in sulphur deposition means that many rural areas of the UK currently receive less than around 5 kg/ha of S from the atmosphere. The following recommendation take this into account.

Oilseed Rape
Most oilseed rape crops require a minimum 100kg/ha SO3 sulphur. Crops therefore require an application of 75 – 100 kg/ha of SO3.

Cereals require approximately 60kg/ha SO3 of sulphur and much of East Anglia and many areas in the North East are at medium risk of sulphur deficiency. Crops in these areas therefore require approximately 50 kg/ha SO3 sulphur.

Historically, maize was grown in rotations with often large inputs of manure and slurry, which usually provided sufficient sulphur for the
crop. With maize being increasingly grown outside livestock areas it is important to consider the sulphur requirement of the crop and an
application of 50-75 kg/ha SO3 particularly on light soils is usually required.

Most brassica crops have a relatively high requirement for sulphur and adequate levels of sulphur are required for improved taste in a number of vegetable crops. Sulphur is also required to ensure efficient nitrogen utilisation in vegetable crops, with deficiency often resulting
in reduced nitrogen responses. Application of 40-50 kg/ha SO3 is recommended in responsive situations.

Sulphur deficiency reduces the yield and quality potential of grassland and is exacerbated by high forage removal rates. Responsive crops require approximately 40 kg/ha SO3 . Top-dressing with Nitroflo 20+S provides immediately available sulphur to supply the crops needs

liquid fertiliser experts

Speak to your local Liquid Fertiliser expert about supplying Sulphur to your crop. You can find out who your local contact is by using our handy postcode tool, here.

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