12 April 1996

Quarter at risk of sulphur deficiency

A QUARTER of the UKs wheat crops look susceptible to sulphur deficiency this year, according to results from a mini-survey.

Hydro Agris SulphurWatch service analysed soil samples collected from over 50 representative crops throughout the UK. About a quarter proved to be at high risk of sulphur deficiency and would benefit from receiving sulphur fertiliser, says Dr Geoff Paulson, head of agronomy at Hydro.

The finding suggests a worsening of the situation – earlier Hydro field trials had suggested 10% of crops would give a significant yield response to sulphur. In those cases applying 37.5kg SO3/ha (30 units SO3/acre) or 15kg S/ha (12 units S/acre) gave a full yield response. "Higher application rates give no further yield benefit," says Dr Paulson.

Half the crops in the SulphurWatch survey were at medium risk. While those are unlikely to give a significant yield response to applied sulphur, careful monitoring is warranted. &#42