Deep - "here" - is 5 to 6", or about the depth that most shank tools would run. I think the research I am quoting was done with some early Yetter 'Maverick' units.

We were of the same opinion - get the P&K on in the fall, indexed to the row and follow with the planter next spring simply carrying nitrogen. The problem 'here' was that there was zero response to the fall applied P&K when compared to a strip with no P&K down.

Since then, we modified the tubes on our own shank type strip unit to spread the granules in a fan pattern out behind the shank where the berming coulters will contain it and fold it back into the strip. That is why I had always admired your Pluribus's dry placement and mixing in the tilled band.

Again, I think your customer is very innovative. Perhaps, if he would, try a few strips of placing it at the 2-4" depth where there was relative certainty that the Pluribus would get ahold of it next spring and fold it in. It would be interesting to take a couple of replications to yield and see if the 6" depth or the 2-4" application depth are different, and to which favor.

Last, to address folks that want it 'deep', whether that is 6" or 12-14", I'd delicately challenge them as to whether they had done the research to determine the correct depth, or whether they are doing it by intuition. I recognize that in some soils and some climates, deep placement is done because that is where the roots are feeding in summer because that is where the water is, and the soil surface is so hot that there are few functioning roots near the surface. Otherwise, they may find out - like us - that the old guys were onto something with the 2x2 band.

Really, I am trying to be a little help here...!

Luke      aka Ken in SWOnt