Closing wheel type and row unit downforce can affect corn germination in no-tillage production systems

Adopting no-till planting can have many soil health benefits and cost savings but may present challenges with respect to planter performance. Aftermarket attachments such as hydraulic row unit down force and closing wheels have been hypothesized to overcome the challenges of uneven planting depth and poor furrow closure due to residue within the field. In addition, starter fertilizer could improve early season growth in cooler soil conditions. This study evaluated the effect of closing wheel type, row unit down force, and starter fertilizer on corn (Zea mays L.) emergence and yield across soil types and micro-climates within Wisconsin. Aftermarket closing wheels were compared to a standard (rubber) factory provided one, within two down force settings (Low at 333 N and High at 667 N) and liquid starter fertilizer (0 and 47 L ha(-1) of 7-21-7). The standard rubber closing wheel with high down force resulted in lower emergence compared to the low setting (p = .013). No effect of starter fertilizer was observed on either emergence or yield. Aftermarket wheels resulted in greater emergence regardless of down force setting, which might appear to be an advantage from an operator point of view, but greater corn emergence did not result in greater yield. These and other factors should be considered when selecting closing wheels for a particular set of seeding conditions.