Getting planting depth right: The value of properly using active downforce

By John Fulton, Ohio State University

Achieving consistent planting depth remains one of the most important—and most challenging—steps in establishing a uniform, high‑yielding corn crop. Variability in soil type, moisture, and residue across fields often causes row units to ride up or sink, leading to shallow or inconsistent seeding. Recent multi-year research from Ohio is helping clarify just how much planting depth and downforce matter—and what growers can do to manage both more effectively.

A three-year Ohio State University study found that final planting depth frequently differed from the target depth, with seed placement tending to be shallower than intended across a wide range of soil conditions. Soil texture, moisture, and field topography were the three primary drivers of depth variability. The study also confirmed that planter downforce settings significantly influenced final depth, with higher downforce increasing seeding depth on average by about 0.1 inch when increasing from 100 to 200 lbs. of applied force in one central Ohio year.

Our research documented that active downforce systems greatly improved depth consistency, reducing variability by an average of13% compared to mechanical springs. Systems properly tuned achieved a seeding depth coefficient of variation below 8%, a major improvement over the non-active control.

These findings align with emergence and yield studies across the Midwest showing that shallow planting (<1.5″) increases the risk of poor root development, late emergers, and yield‑limiting “runts.” Studies from Ohio State University and DuPont Pioneer demonstrated 13%–40% yield losses when corn was planted at 0.5 inches compared to 1.5–3 inches; these losses were largely driven by reduced final stand and uneven emergence.

While depth alone does not guarantee higher yields, depth consistency plays an essential role in uniform emergence, one of the strongest predictors of yield potential. Late emergers become uncompetitive “runts,” contributing far less to the final yield.

As planters become more sophisticated, our research indicated that active downforce is one of the most effective tools available to help growers achieve consistent, uniform planting depth across variable soil conditions here in Ohio, giving every seed a more equal start and protecting the crop’s full yield potential.

As you prepare for the 2026 planting season, take time before and during planting to verify that your row units are placing seed at the intended depth under your field conditions. Soil moisture, texture, and residue can change dramatically across even small sections of a field, so stopping regularly to dig seed and confirm seed depth is essential. Make sure gauge wheels are making firm, even contact with the soil, and adjust downforce as conditions change throughout the day. Tools such as the PTx SmartFirmer can greatly assist in this process by providing real‑time feedback on moisture and temperature, helping you fine‑tune depth settings on a field‑by‑field basis. Combining careful depth checks, calibrated downforce, and in‑furrow sensing technology will give your crop the uniform start it needs for strong emergence and yield potential in 2026.

You can find additional information about our planter research and related seeding studies at: https://digitalag.osu.edu/precision-ag/research-focuses/precision-seeding.

Dr. John Fulton is a Professor in the Food, Agriculture and Biological Engineering Department at Ohio State University and can be reached at fulton.20@osu.edu.