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.