SCMN06,

One of the very real and very common problems with in furrow popup I run into all the time is the application system and rate.

Many folks get to the end of a 40 acre field, see the tank is down 200 gal and say "I put down 5 gal per acre"

Meanwhile on the planter some rows are getting 10 g/a (and burnt) others are getting 1 or 2 or none and no benefit. Yes, this is a situation where there is actually going to be a decrease because of the crop damage from 10 g/a. actually 7 g/a will cause damage in furrow in some soils and weather.

There may also be the issue of the "quality" of the 10-34-0.

However I would bet a cup of coffee and maybe even a donut that the culprit to cause a decrease is the planter plumbing arrangement. 

I have seen Deere dealers who "forgot" to put the orifices in the standard JD 1790 liquid fert coulter system - resulting (with 28%) in very green to burned corn in the center and yellow corn on the outer rows.

Most manifold type flow dividers, even though expensive, just don't work well at very low flow rates like 5 or 6 gpa.

I have never seen a case where a properly and accurately applied 5 to 6 gal/a rate of 10-34-0 "hurt" yields.

Jim at Dawn

I should add that the best way I have seen to apply 10-34-0 at 5 or 6 gal/a is to run a large (1" or 1.25" dia) manifold/tube all the way across the top of the planter frame (with hose at the pivots) and directly in front of each row drill a hole in the plastic and mount a Teejet body with a screen and an orifice plate small enough to get the pressure up to maybe 50 psi at the desired rate and speed and row spacing (see the Teejet catalog). Also put a gage in the center and at one end of the manifold.

From the body on the frame in front of each row to each row, run the SAME SIZE AND LENGTH tube from the body to the row unit application point, Totally Tubular, Keeton, Rebounder, etc.

You must have EXACTLY the same resistance to flow between the orifice and the discharge point on every individual row. No kinks etc. I like the Totally Tubular type of all-steel tube because they use relatively large dia stainless tubing and the attachment point is up where you can see it and get at it not buried between disk openers.

Many folks try to put the orifices up on the center section where they can see them and run little itty bitty tubes ("because its only 5 gpa") out to the end of the planter which results in dramatically different delta P across the orifices or flow divider. This results in dramatically different rates going to each row.

Then they complain because they saw a decrease from the 10-34-0.