**The tankers pull a knife plow behind the rig, knife the soul about a meter deep**
A meter?? In IL I grew up on a farm, farmed until I was 46, continued to live on a farm, until moving to TN, then trucking for a farmer 4 years until cutting back to part time 2 years ago.
I have never applied or seen applied, fertilizer knifed in the ground more than a foot. The deeper, the more it gets leached into the subsoil and lost.
Note to any readers....set your manure knifing rig to 18 inches please! For you EU internet farmers, that's only 1/2 meter deep. (Roughly)