How To Set Down Pressure in a Wet Spring
May 06, 2011
Question: I attended one of the corn college planter clinics and forgot to ask about how the weight of seed in the seed box affects my down pressure. I was also wondering how much is too much in a wet spring? I have a White 8202 planter with standard springs and the options are 50,60,105 and 115 lbs and we use it in a corn/soybean rotation with conventional tillage. I understand I should set it for the toughest part of the field that I'm in and check it like they described but I'm struggling with deciding on what that setting should be.
Answer: In conventional tillage, you are ideally planting into 4" of uniform soil behind your soil finisher. If the seedbed is not uniform or you are planting too fast, then that will require more down pressure. Typically, if the conventional tillage is done properly, the weight of the row unit plus the weight of a full seed box will be enough down pressure. However, it could be very likely that you'll need to carry between 50 to 100 lb. of down pressure.
To review, down pressure does two things: it maintains the depth of the disc openers and it ensures a true V. To check if you are achieving a true V, secure one of the press wheels up with a strap. Then run the planter and check to see if its a nice true V on both sides.
Setting down pressure correctly often demands walking a fine line and making on-the-go decisions. Sidewall smearing occurs when too much down pressure compacts the soil around the seed and brings dry soil on top of the seed. This can lead to uneven emergence. Too little down pressure will mean you do not maintain depth or close the slot behind the planter.
This blog is provided as an interactive way for you to have your questions answered by our Farm Journal Agronomists. E-mail your nitrogen, soil fertility, soil density, planter set-up, scouting, and other questions to: TestPlots@FarmJournal.com.
