Fertilizer Association of Ireland - Frequently Asked Questions

Q.10 How will I know if my fields need sulphur?

A. A Sulphur deficiency is indicated by yellowing of the younger leaves. It occurs mainly on sandy free draining soils with a low organic matter content. There is no reliable soil test for sulphur and deficiency is diagnosed by means of herbage analysis. If you expect a sulphur deficiency you can confirm it by applying a sulphur containing fertilizer to the affected fields and leave a small area spread with the equivalent fertilizer without sulphur to see if there is a difference.

Q.11 Can there be problems with too much sulphur?

A. Excess sulphur can depress the uptake of selenium in herbage and reduce the absorption of copper by animals. It is important to apply sulphur only where it is needed and at the correct rates. Problems are rare but are less likely to occur if you avoid fertilizers with high levels of S (e.g. sulphate of Ammonia).

Q.12 Can I spread urea in the same year as I spread lime ?

A. The response to urea can be very poor if it's applied within eight weeks of an application of lime. A reaction occurs between the urea and the freshly applied lime particle's which results in much of the urea being lost to the atmosphere as a gas (volatilisation).

As a general rule don’t use urea if lime has been applied that Spring. If lime was applied in the previous back end it should be safe to use urea in the following Spring provided there was sufficient rainfall to wash the lime into the soil. Lime can be applied a week after an application of urea with no increased risk of losses as the urea will have been fixed in the soil and no reaction occurs between the urea and lime particles.