> How long can chemical
> fertilizer(n/K2O,etc.)lay in the
> field without rain before it
> leahes out and is not effective?
Don’t worry about the potassium or phosphorous, it'll stay put until it rains, nitrogen is the one you have to concerned about but it depends on the type of nitrogen. If you use urea, which is 46% nitrogen you can lose a lot if it don’t rain soon after being applied especially if it’s humid out. If you use ammonium nitrate it should stay until it rains.