There are many systems to help set the rate of fertiliser spreading correctly. The removal of a disc and the weighing of the fertiliser that falls into a bucket in 30 seconds and some simple calculations can give large improvements in rate control for a small investment of time.

This is often more difficult as the spreader ages due to corrosion of the disc removal mechanism. And more harm may be done to the pattern and rate during the removal of the disc than would be gained by doing the test.