A. May is the cut off point for use of urea. Research has shown that even in cool wet summers urea did not give as reliable results as CAN as higher soil temperatures increase losses. A useful rule of thumb is if you kneel down in a field of grass and your knees are dry when you stand up it is too dry for urea. If there are very good drying conditions in April conditions may not be suitable for urea particularly on bare ground.
