Cover Crop Termination including Planting Green

Cover Crop Termination: I always enjoy seeing new life and the seasons, so enjoying seeing wheat/rye greening up! Grateful for the excellent discussion around termination timing at the February practical cover crop management meeting! Pictures with more details each farmer shared is at jenreesources.com.

In a column last year, I shared detailed considerations for termination timing (prior to planting vs. planting green). That info. can be found at:  https://jenreesources.com/2021/03/28/jenrees-3-28-21/. For this column, sharing key tips from the discussions that may be helpful for this year.

Key points I gleaned:

  • While rye may die slowly depending on the temperature and year, it will die.
  • Two farmers consistently killed rye with only 20-22 oz/ac of Roundup Powermax (even when headed). For those who planted vetch with rye, the vetch will survive the Roundup application allowing it to grow longer, produce more nitrogen, and be killed by a post-application containing a Group 27 herbicide (like Callisto) later (if want it to die).
  • Clethodim vs. glyphosate: Two farmers and a Pioneer rep shared sentiments of clethodim providing a slower kill and allowing the rye to stay greener longer for weed/erosion control. This is of benefit especially for farmers who need to terminate prior to corn or seed corn planting.
  • Regarding clethodim rates, several are aiming for the mid-range this year by using 12 oz/ac. Another farmer used 10 oz clethodim + warrant. Many use 8-10 oz/ac to kill volunteer corn in soybean, so a few are also trying the lower rate. When going into corn, clethodim needs to be applied to rye to kill it at least 7 days prior to planting corn. For soybeans, it can be applied anytime after planting/emergence if desired.
  • When rye is greater than 12”, consider increasing gallonage to 15-20 gal/ac for better coverage.
  • When considering planting corn green into rye on subsurface drip irrigation (SDI), need the ability for higher capacity well to get moisture up to the seedbed. Potential yield loss otherwise.
  • When planting soybeans green, the goal is often to off-set the PRE herbicide cost with the cover crop seed and application cost. A residual is necessary at some point either at time of termination or up to a week after termination when planting soybean green. Plan on irrigation or rainfall to get the residual to the ground, especially on rye taller than 12”.

My key points for planting green include: plan on some form of nitrogen at planting if planting corn green into rye, have the pivot ready to go if need moisture for the seedbed, don’t use a PRE in soybean if can’t get seed vee closed, plan to water residual application as soon as label allows to get residual to ground, and if non-irrigated, consider seedbed moisture for termination timing.

Lawns: Lawns are slowly greening up and for those with fall armyworm damage last year, overseeding and/or replanting may be necessary. Consider overseeding now as Kentucky bluegrass overseeding is recommended from April 1-30th and tall fescue from Apr. 15-June 15. The full seeding rate for 1000 sq ft is 3-4 lbs for Kentucky bluegrass and 8-10 lbs for tall fescue; for overseeding, use ½ these rates. Small amounts of sawdust or sand can be mixed with the seed to aid spreading. The area should be prepared prior to seeding by raking to loosen the soil and excess dead growth. Areas can also be aerated or power raked (power raking should only be used if ½” thatch or greater is present). Scotts TurfBuilder Starter for New Lawns can be spread either immediately after seeding or one can wait till the seedlings emerge. Either way, it is safe for the seed/seedlings. Spring rains in April will greatly help with emergence, but otherwise, irrigation by mid-April will be necessary to keep the soil moist until germination occurs. Then apply water deeply and infrequently to encourage rooting. Also check out this excellent brochure for Lawn care in Eastern NE: https://go.unl.edu/mhkd.


Thank You to the following for their contributions to this information: Gabe Bathen, David Cast, Chad Dane, Jay Goertzen, Marvin Linhorst, Ron Makovicka, Kevin Medow, Brad Morner, Scott Richert, Todd Schmeiding, Stuart Spader, and Mike Spray. The photos are mostly mine from field visits other than the ones taken by the farmers from their tractor cabs.

About jenreesources

I'm the Crops and Water Extension Educator for York and Seward counties in Nebraska with a focus in irrigated crop production and plant pathology.

Posted on April 3, 2022, in JenREES Columns, Lawns and tagged , , , , . Bookmark the permalink. Leave a comment.

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