The spring planting season in Iowa is quickly approaching. Therefore, it is critical to prepare now and check a few items when starting each field. While it takes time to check these items, field research has shown that getting the correct gauge wheel pressure (downforce pressure) to help create the best possible seed furrow is critical to yield potential.
Setting the proper downforce pressure will depend on the type of downforce system on your planter. For example, spring, air or hydraulic systems are all commercially available options. The goals across each are the same – get the correct amount of force on the gauge wheels to keep the row unit in the soil, maintain the correct seed depth and create a quality seed furrow.
This was one of the key topics that the Digital Ag Innovation Lab covered at this year’s Planter University, presented by Iowa State University Extension and Outreach. During these events, the instructors used portable containers filled with soil and a planter unit mounted on a mobile cart to demonstrate how using different downforces causes varying firmness of the seed furrow.
The goals for downforce include:
- Maintaining ground contact - keep the row unit in the ground at the set depth.
- Setting soil structure - press out air pockets and set soil density next to the furrow.
- Furrow structure - furrow holds its structure while seed is placed at the bottom, then furrow is closed from bottom to the top by the closing system.
The best practice when you start to plant a field is to put the planter in the ground and start planting seed like you normally do in the planting operation. After you have planted for at least 50 feet, then stop and get out of the tractor to review the seed trench structure. The first place to start looking at the furrow structure is between the gauge wheels and closing system. If there are high amounts of soil in the furrow on top of the seed, then downforce should be increased to improve furrow integrity. In some soil conditions applying more downforce will not continue to improve the quality of the trench structure. For example, extremely dry and sandy soils. Therefore, if this is occurring, then reset the downforce to the last downforce that made a noticeable improvement in the trench structure. Downforce 
setting requirements will change and need to be monitored often as soil and moisture conditions change within a field as well as across different fields planted on the same day. The goal is for the planter operator to determine the correct gauge wheel load for any given field condition and to adjust as needed.
A second option is to evaluate downforce settings by using a small chain, wire or other device that can hold up the closing wheel system just while evaluating downforce settings. This allows easier access to assess the seed furrow in more detail without having to do the inspection down through the gauge wheels. Also, this procedure can be useful when the operator is troubleshooting a single row unit issue.
For additional information and resources on equipment and technology, visit Digital Ag Extension.