What's the Deal with Down Pressure?
With planting just around the corner, we wanted to spend some time in the next few weeks talking about some planting topics. First up this week is down pressure. The world of down pressure has changed dramatically the past few years. Gone are the days where we set our spring pressure to maximum and hit the field. Now, we are living in a world with row by row accuracy, adjusting based on feedback from individual load cells to give you the best possible seed placement.
Why do we care so much about down force?
One of our major planting goals is optimum seed placement and good seed to soil contact. Down force is an integral component in that goal. Our down force is responsible for maintaining optimum seed depth and placement across variable field conditions, changing moisture, a variety of soil and types, changing residue quantities, and harvest and spraying compaction.
More doesn’t always equal better.
Applying more down force doesn’t necessarily get us better seed depth or placement. In fact, it can cause compaction issues, too deep of seed placement, and a whole host of problems that can give us a poor start to the growing season. More pressure isn’t our goal, more precise and accurate pressure is.
What we are working with:
Our three systems of down force are the good old fashioned springs, pneumatic airbags, and hydraulic cylinders. We can get pretty decent results with both springs and airbags, particularly if we don’t have a lot of variation across a field. Additionally, these can work well if you get out and check performance periodically throughout each field. Keep in mind, you are setting a set value of weight for each of these systems across the whole planter frame. Hydraulic cylinders are really the next step up in terms of row by row controls as well as feedback from the system itself to set the needed weight. As you cross over or follow a sprayer track, the hydraulic cylinders can adjust that single row to compensate for the change. Additionally, these systems have the ability to actually lift some of the row unit weight in scenarios where the weight of the row unit is still too much down pressure.
In Field Adjustments
While a lot of planter prep is done before we hit the field, adjusting down pressure is one that needs to be check and adjusted in each field, and preferably within each field multiple times. For spring or pneumatic units, the down pressures should be set where you can barely turn the gauge wheel when the planter is set down. This is probably best to do when the planter is about a quarter full and not completely filled as the change in planter weight can impact the row unit performance. (It's going to be easy to get enough down pressure when the planter is full. It's another thing to get it set correctly when your planter is lighter and running out of seed.) Another rule of thumb is you should be able to dig up the seed with your finger. If you can’t, back off on the down pressure and check again.
What do the results say?
Recent studies across the last several years have shown the benefit of using a system that can more precisely manage down pressure like the hydraulic systems. If you are considering some planter upgrades, this might be a product you should consider. However, even if you don’t have a system like that, we can still work to improve our results. Stop and check your down pressure in several spots across the fields, and make changes accordingly. The more frequently you check, the more likely you are to catch any issues with the system performance. This is particularly true with changing field conditions or after a rain or a change in tillage type.
While many of these points are not new to you, it’s always a good reminder as we head to the field to be implementing our best management practices, including our patience, and persistence to get things done right!