Is sulphur worthwhile in early applications?
BEFORE ordering next years fertiliser, consider whether including sulphur in early season applications is worthwhile, advises Devon independent consultant John Morgan.
"Atmospheric deposition has declined as the industrial sector has reduced emissions. In 1999 it was 15% of that in 1980," he says.
Deficiency is now becoming common in grassland, according to Mr Morgan. Soil type and location are the best indicators of likely deficiencies. "Sandy, shallow or medium soils that are low in organic matter are at most risk because the form of sulphur used by the crop is leached. Crops may also have pale leaves and stunted growth."
In grass, it is often second cut on farms using high nitrogen rates that show this pale colour, he says. However, problems are seen in first cuts on the most vulnerable soils.
A leaf test can also help identify the need for sulphur. An improved test has recently been developed by the Institute of Arable Crops Research, Rothamsted (Arable, p54). *