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

Commodities

Practices

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 3 issues which may reduce crop yield:
interception of residual herbicide 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 solution was fairly aggressive use of row-cleaners in both
corn and soybean to both clear crop residue and partially
dislodge rye plants creating a row clear of plant residues to
improve spray coverage, limit noncrop nutrient uptake and create
an unfavorable environment for slugs while also increasing soil
warming. The problem with this approach is dislodged plants can
build up the spike wheels requiring frequent cleaning and
partially dislocated plants can make slot closure more difficult
and both 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 competition with the crop.

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

Solution

The use of row cleaners and their impacts on both corn and
soybean production and yield will be examined in field trials in
2024 and 2025 on my farm near East Troy Wisconsin. The soil type
is a Fox silt loam (common in the region) and has a 20-year
continuous no-till history; in corn-soybean rotation for the past
10 years. Crops have been green planted into cereal rye for the
past 3 years. Rye is typically 6-8” in height at planting.

We will evaluate 3 levels of row cleaning: none, row cleaners
removed; light, row cleaners engaged enough to remove some crop
residue without dislodging rye plants; and heavy, total residue
removal with significant rye dislodging. The independent corn and
soybean trials will use the other routine cultural practices of
the farm including use of starter fertilizer to meet P and K
maintenance requirements for either crop in addition to S, as
well as the crop specific residual herbicide, applied
preemergence along with glyphosate for rye termination. This
application typically occurs 7-10 days after planting (DAP) in
corn but in soybean can be split, depending on soil moisture
conditions. Residual will be applied within 3 DAP, rye terminated
then if conditions are dry or delayed up to 2 weeks if moisture
is favorable to increase biomass production and weed suppression.

To assess the impact of row cleaning on the production issues
discussed above we will measure:

Emergence dates (first, 50%, final)

30 days after emergence (DAE)

• Final stand with concurrent:
• % slug feeding damage (plants)
• % peepers (plants of reduced size indicating delayed
  emergence)
• Visual weed control rating (in-row plant density will be
  measured if differences occur)

Tissue nutrient concentration (V6 for corn, R1 for soybean)

Grain yield at maturity (harvest stand, yield, grain moisture and
test weight)

The experimental design is a randomized complete block with 4
replicates. Plots will be 100’ in length and the center 2 rows
(both crops planted in 30” rows) will be harvested for yield
determination. We will establish two (2) 20’ sections within each
set of harvest rows to measure emergence dynamics and take the 30
DAE measurements, ensuring we are measuring the same spots
eliminate planter row unit and other spatial variability. Normal
data will be subject to analysis of variance; count and
proportion data with glm using the appropriate error family (R
Studio 2023.09.1).

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.