DownForce: Myth or Fact?

DownForce: Myth or Fact? from Central Valley Ag on Vimeo.

by Keith Byerly

by Keith Byerly

After talking about water for the last few weeks, its time for a break. We have been through a wet spring and planted in a variety of conditions. I realize that most of you have your corn in the ground by now, and some of you can even row it now. As you are finishing up with planting, it’s time to evaluate what we have done in a variety of arenas. I want to look specifically at the performance of your downforce system.

Before we talk about how to evaluate the downforce, we need to understand why we talk about it at all. Whether we are talking about springs, airbags, or hydraulic, the basic principal of downforce remains the same. Our goal is to keep row units in the ground at all times. Only by keeping weight on our gauge wheels at all times can we ensure that we maintain seeding depth. Springs did this on a row by row basis, but they always applied the same amount of pressure down, so there was no way to relieve weight on the row when you didn’t need it. Then came airbags. They gave us the ability to add or remove weight as we desired. Then somebody had the idea to add sensors to the system so it would automatically maintain the load as our seed boxes and fertilizer tanks changed going across the field. Then somebody had the idea to make the sensors tell the system to change for small condition changes, like soil differences, and then even compacted areas. Although this was a great idea, the air bags still had limitations. You can only build pressure with an air compressor so fast, so weight changes happened at a slower rate. Then we began to put hydraulics in place of pneumatics. Higher pressure meant quicker changes and all of a sudden we could add and remove pressure in 1-5 seconds instead of 20-40 seconds. Downforce systems started off splitting the planter into two sections, then 8, and now we are back to where we began, with row by row control.

So on to the myth part. Somewhere along the way, the industry seemed to foster this idea that downforce systems were designed to maintain a gauge wheel load on the planter. While that is true in some examples, really the first priority of any downforce system is to maintain a minimum gauge wheel load so that we never lose ground contact, and so that we maintain seeding depth. Goal number two is to accomplish our first goal with the least amount of force possible. We want to minimize our seed trench compaction. Another myth is that a hydraulic Downforce system will let us plant when conditions are unfavorable. Again, while one of the goals of the system is to minimize sidewall compaction, it will not eliminate it.

EDIT_MAO2390

So instead of addressing facts of the system, let’s move on to what we can do today. A couple of weeks ago, Mike Zwingman introduced some of you to the term NESP – Net Effective Stand Percentage. This term comes from other sources in the industry, but it is quite relevant to this conversation. If you didn’t see “In Flux, Part II” please go back and check it out. As our corn comes up, we need to evaluate our stand like Mike talked about. The main thing we are focusing on is the consistency of the plant height, and also digging up some seeds to seeds to evaluate our depth. By now, I think we all understand the potential yield loss when a plant emerges 48 hours later than its neighbors. We have spent much time on it at Summer Series events, etc… Those late emergers don’t usually come from a seed that is too deep, but from a seed that is too shallow. The warming/cooling conditions a shallow planted seed are subjected to cause it to have more starts and stops.

Downforce systems aren’t a magic wand. They don’t give us an excuse to be out in the fields when it is unfit. But they do give us the opportunity to mitigate small issues from turning into big problems, and it will let us go to a field that is 95% ready and probably be ok. Now is the time to evaluate if a Downforce system is right for your operation, and if it is, talk to an ACS equipment specialist. We have 0% Financing options and can get a system installed on your planter now before you put it away for the season.

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    Very interesting article to read and I got more info about maximizing my compaction wheels. Thanks for sharing and keep it up. Cheers!