Becks multi year trials found it was basically 6 one way, half dozen the other on early Y drop vs coulter applied assuming the crop never ran short getting to the coulter applied. 

We went to an early dry, popup and a 0x2 of 5gal of 32 on the planter and then normal sidedress time app with the bulk of the N and have had great luck with it

Forgot to add that we use a coulter/knife unit to sidedress, we were previously spraying on all the 32 and got hurt once and we knew at times we were losing N but who knows how much?? Not only was it wasting money, but may have been a yield factor at times?? That was our biggest reason to go with the in ground application, in our heavy clay we have no worries of leaching, but more chances of surface loss from not enough rain or even erosion down the hills.