Up or down: Should row cleaners be used when planting green into cereal rye?

View the project final report

Commodities

• Agronomic: corn, rye, soybeans

Practices

• Crop Production: cover crops, no-till

Planting green into cereal rye enhances sustainability gains of no-tilling and using a cover crop but presents technical challenges which may prevent adoption. In my case, I was initially concerned with three issues which may reduce crop yield: interception of residual herbicide spray by the green canopy reducing its efficacy; uptake and immobilization of nutrients applied as starter fertilizer; and creation or maintenance of a favorable environment for slugs, leading to more crop damage and/or stand thinning.

My initial approach to planting green was aggressive use of row-cleaners in both corn and soybean to both clear crop residue and partially dislodge rye plants. The rationale is to create a row clear of plant residues to improve spray coverage, limit rye nutrient uptake and create an unfavorable environment for slugs while also increasing soil warming. The problem with this approach is that dislodged plants can build up the spike wheels requiring frequent cleaning and partially dislocated plants can make planting slot closure more difficult. These problems are compounded by the wetter soil conditions of no-till. Based on observation, I am also of the opinion that disturbed plants are slower to die after application of termination herbicide, creating more competition with the crop. Aggressive row cleaning also accelerates wear on soil engaging tools, increasing maintenance costs.

Is row cleaning really necessary in a plant-green system on my soil types?

We conducted replicated trials in corn and soybean over the 2024 and 2025 growing seasons, evaluating three levels of row cleaning: none; intermediate (enough to remove crop residue but not dislodge rye); and full, removing crop residue, disturbing soil, and dislodging in-row rye plants. We measured crop emergence dynamics, plant populations (stands), slug damage, tissue nutrient concentration at flowering and grain yield at maturity and used common statistical methods to determine if differences we observed between treatments were real. Project results and lessons learned were shared at a field day and at other outreach events.

Results were inconsistent in corn. Averaged over years, there was no apparent yield difference caused by row cleaning but inconsistent performance by the intermediate level of clearing clouds the results and introduced some uncertainty in the analysis. Comparing just the full-up and full down treatments, it was obvious that the need for row cleaning was dictated by conditions at planting: row clearing was unnecessary under warm conditions when rapid crop emergence can be expected while there was a clear advantage under cooler conditions. In soybean, we found a clear disadvantage under warm conditions, similar to corn. We were unable to test the response under cooler conditions, warranting further investigation.

We will continue this work to gain more years of insight. Meanwhile, in our routine crop production we will make the adjustment based on soil temperatures and conditions at planting: no clearing if rapid emergence can be expected and full clearing if not.

Objectives

1. Determine if row cleaning impacts crop production and yield in green planted corn and soybean comparing no cleaning to two levels of residue removal: light and heavy (near complete removal as practiced currently.
2. Communicate results and experiences with the no-till community and their advisors.