From Crop Action Feb 2022:

Sulphur is an essential plant nutrient and has important effects on both the yield and quality of crops. Mineralisation of soil organic sulphur will supply some of the crop requirement but if this is not sufficient, yield and quality can be reduced unless additional sulphur is supplied.

The AHDB Nutrient Management Guide (RB209) includes sulphur recommendations for all crops. RB209 recommends applying 25-50 kg SO3/ha for cereals and 50-80 kg SO3/ha for oilseed rape where sulphur deficiency has been recognised or is expected. Sulphur should be applied as a sulphate containing fertiliser in the spring, usually with the first nitrogen application.

Crops grown on light textured sandy soils are at greatest risk of sulphur deficiency. Recent AHDB funded work has shown that soil texture and over-winter rainfall is the best predictor of sulphur deficiency in oilseed rape. Leaf tissue testing was less reliable and topsoil analysis was not a useful indicator of likely yield response to S fertiliser.

Sulphur risk matrix to estimate the likely responsiveness to sulphur

Actions:

• Use the sulphur risk matrix to assess the risk of sulphur deficiency.
• Apply sulphur to all cereal and oilseed rape crops grown on high or moderate risk sites:
  • Cereals 25-50 kg SO3/ha
  • Oilseed rape 50-80 kg SO3/ha
• Apply sulphur as a sulphate containing fertiliser at the start of stem extension in the spring.