Part 2: Fertilizer Placement and Down Pressure
Basically we have liquid set up for fertilizer on this planter. We have three tanks for our liquid fertilizer. A fill line right here. What we want to importantly talk about is the opener and delivery system in the field for the fertilizer. Ok, we have our depth gauge wheel, our single disc right on the inside. And then on the inside of that is our shoe to deliver our liquid fertilizer. It's very important, field studies have shown that if your row is on the disc side of this set up you'll suffer some yield loss. It seems like that single disc will happen to seal the side wall of the opening and it's harder for the roots to get through and penetrate and get into that fertilizer band where as if you're on the shoe side, have the shoe between the disc and your row kind of breaks up that soil a little bit and your able to get into that fertilizer and some of the Midwest long term research has shown you know nine to fourteen bushels yield advantage by just having that shoe on the right side of things here. So this one is set up right. The shoe is towards the row, the single disc is away from the row, furtherest away from the row and it's going to deliver the material right where you need it. Another important consideration in no-till, I think the only time you really need to make sure the fertilizer is into the soil is when you're putting on fertilizer that contains phosphorus and if you have a low testing phosphorus soil you want to get that phosphorus in the soil because it moves so slowly into the soil and if you put it on the surface this year basically it's going to be there for the next couple year crops not this years. So if you need to get that phosphorus down where the roots can get into that band make use of that fertilizer on your crops this year. So if you have phosphorus limited production system you want to be sure you're getting that phosphorus near the seed where it can take it up. And that's historically what this particular rig has been used for; not heavily manured or any manure on the farm.
And we're getting that phosphorus where the plant can use it and we're getting a yield advantage in no-till by doing that precise placement.
Ok in this unit we have two different fertilizer delivery systems. We have the metal tube, which will deliver fertilizer into the seed furrow and it may have some wear issues because it's between the double disk opener on your planting unit. But if its guarded and adjusted correctly, guards here, guards here, it should be, do a pretty good job of delivering fertilizer.
The other system and this would be more of a high flow system by the way, the other system here is with the Keeton the seed firmer where you have delivery tubes built into the firmer and it's that which ride along the soil firming the seed. You would deliver the fertilizer out the tubes into the seed furrow.
You notice in this particular planter we have a liquid tank for fertilizer which is delivered through the Keeton seed firmers at the planting units. And we also have dry fertilizer boxes in which we're using a dry fertilizer. The farmer is using a dry fertilizer and he's dribbling that on the soil surface. And you can see the fertilizer tubes attached, to brackets that would be over top of the row. So he's dribbling it from this tool bar to the soil surface and creating about a 7 to 8 inch band of dribbled fertilizer. And that works fine for nitrogen and nitrogen-potash mixes; probably not the most efficient way to put phosphorus on. It works great and you get some slug suppression or you keep them out of that row. They can't take the fertilizer.
You want to make sure your planter is equipped with heavy duty down pressure springs. Of course now you're talking older planters, some of them with air bags and all the things that we use anymore. But this would be more of a typical planter out in the field today yet. Down pressure springs usually two of them the heavy-duty type. You want to make sure they're adjusted-up right because if they're not you're not going to have enough down pressure.
You have a bolt that's threaded into the head of the down pressure spring. And you have a certain adjustment, usually I think the maximum amount of tension you need to have on there is where you have an inch and a half from the inside head of the bolt to the lock nut on the down pressure spring which would be just inside here. You can't quite see it, but when you're working with the equipment it's right there, an inch and a half of open bare bolt. If you get more tension on that, in other words if you tighten it more, what usually happens is you don't get any better performance out of your unit, but you will have to replace springs rather often because they can't take that kind of a stretch and you'll break springs and be replacing them. But generally in rough conditions you know an inch and a half is a pretty good place. I think that's about as tight as you want to make them for most conditions. For John Deere, that's the limit. A lot of these adjustments you're given ranges, an average place to start and then a limit, not to go past, and I have seen so many situations where those limits have been exceeded. And once you start exceeding limits at one spot, you're going to throw something off somewhere else in the planter.
So don't exceed those limits that are set for tolerance on the planter.
Planting unit pneumatic down pressure has some great utility. Down pressure tension is much more easily adjusted than a spring down pressure tension assembly. The ability to adjust air pressure to match the planting unit down pressure requirements of each field in each set of planting conditions will be very helpful in establishing a very high yielding crop. Monitors that accurately measure the actual down pressure on each row unit will maximize the usefulness of the pneumatically adjusted planting unit down pressure assembly.