The Oregon Ryegrass Commission has published three helpful new flyers to aid in your selection and management of annual ryegrass as a cover crop.
1. Selection of Annual Ryegrass
2. 2014 Annual Ryegrass Management Guide – “Quick” 2-pager
3. 2013 Annual Ryegrass Management Guide – Comprehensive 4-pager
Please let us know if these could use further information or clarification.
All of these and more are available on the Annual Ryegrass Cover Crop website.
Soil health is the main focus at Wenning Farms, in the rolling hills and tight clay soils of southeastern Indiana. The family operates more than 600 acres in a corn/soybean rotation.
Roger Wenning, the son of the founder of the farm, talks here in a video about his practice of rigorous on-farm research and field trials. His efforts paid off last year with good production even in the drought. His efforts also netted Roger the annual Conservation Award from the American Soybean Association.
Roger cover crops his entire acreage, has tried many different cover crops, and still makes a lot of use with annual ryegrass, because of its being a deep-rooting plant that sequesters N for the following corn plants.
A recent article by Farm Journal writer Darrel Smith, talked about a nitrogen study with different cover crops, and the importance in managing the burn down so as to maximize nitrogen uptake by corn and beans.
Farm Progress worked with Dan Towery and Ken Ferrie on the project. The following paragraphs are from the article. To read the entire article, click above on the Farm Journal highlight.
“Annual ryegrass is a nitrogen scavenger, and has a relatively low C/N ratio—as low as 17/1 if you burn it down early,” Towery says. “Because the annual ryegrass was planted into wheat stubble, it may not have taken up much nitrogen because there wasn’t much in the soil to begin with—possibly less than 20 lb. per acre. I’ve seen annual ryegrass take up much more nitrogen than that—90 lb. to 120 lb. per acre, depending on field history.
“The low C/N ratio of annual ryegrass means that typically 50% to 75% of that nitrogen becomes available to corn plants six to 10 weeks after it is killed in the spring—in late June or early July,” Towery continues. “Often, corn fields following an annual ryegrass cover will be dark green, or even almost black in July. That has to be from the nitrogen mineralized from the annual ryegrass, and the absence of a carbon penalty, resulting from the crop’s low C/N ratio.
Now’s the Time to Begin to Take Out Your Annual Ryegrass Cover Crop
1. Timing is important. Late March – Mid April, depending on Midwest location
a. Burndown when the plant is 6 – 12”, before 1st node develops
b. Allow 5 – 7 days after annual ryegrass has begun to actively grow before spraying
2. Temperature is crucial. Should be above 60° F
a. Spray on a sunny day if possible
b. Wait a few days if nighttime temps dip below 38°F
c. Soil temperature should be above 45°F
d. Stop spraying about 4 hours before sunset to allow for max. translocation within the plant.
3. Coverage. Be thorough, use medium spray droplet and moderate pressure
a. Use flat fan nozzles, at 30 – 40 psi
b. Don’t use air induction nozzles that produce a course droplet size.
4. Primary application. One application of glyphosate may be enough for burndown
a. However, plan for two applications, using herbicide with a different mode of action
b. Scout the fields afterwards to ensure annual ryegrass is dead (it may look brown but can grow back)
c. Glyphosate use. Apply at 1.25 – 1.5 lb. a.e./a
d. Add ammonium sulfate and a surfactant
e. Adjust pH and follow mixing directions on the label carefully
f. When using additives, mix them first for 3 – 5 minutes in a full tank of water, before adding the glyphosate; water should be free of clay particles.
5. Precautions, and other herbicides to use when planting corn
a. Never mix atrazine or Callisto with glyphosate (ryegrass control will diminish)
b. Adding 1lb a.e./a Princep (simazine) improves weed control (not in sandy soil)
c. Use of Balance Pro, Prowl H2O, Resolve Q or Basis Blend, 2,4-D, Axiom at full label rate for residual weed control.
6. Use of other herbicides when planting soybeans
a. After beans emerge, annual ryegrass escapes can be controlled with full rates of SelectMax, Poast Plus or Fusilade DX.
b. Use fertilizer, surfactant, crop oil as label-directed. Less effective in cold temps.
Timely Tips for Termination
1. Timing is important. Late March – Mid April, depending on Midwest location
a. Burndown when the plant is 6 – 12”, before 1st node develops
b. Allow 5 – 7 days after annual ryegrass has begun to actively grow before spraying
2. Temperature is crucial. Should be above 60° F
a. Spray on a sunny day if possible
b. Wait a few days if nighttime temps dip below 38°F
c. Soil temperature should be above 45°F
d. Stop spraying about 4 hours before sunset to allow for max. translocation within the plant.
3. Coverage. Be thorough, use medium spray droplet and moderate pressure
a. Use flat fan nozzles, at 30 – 40 psi
b. Don’t use air induction nozzles that produce a course droplet size.
4. Primary application. One application of glyphosate may be enough for burndown
a. However, plan for two applications, using herbicide with a different mode of action
b. Scout the fields afterwards to ensure annual ryegrass is dead (it can appear brown but may grow back)
c. Glyphosate use. Apply at 1.25 – 1.5 lb. a.e./a
d. Add ammonium sulfate and a surfactant
e. Adjust pH and follow mixing directions on the label carefully
f. When using additives, mix them first for 3 – 5 minutes in a full tank of water, before adding the glyphosate;
water should be free of clay particles.
5. Precautions, and other herbicides to use when planting corn
a. Never mix atrazine or Callisto with glyphosate (ryegrass control will diminish)
b. Adding 1lb a.e./a Princep (simazine) improves weed control (not in sandy soil)
c. Use of Balance Pro, Prowl H2O, Resolve or Basis, 2,4-D, Axiom at full label rate for residual weed control.
6. Use of other herbicides when planting soybeans
a. After beans emerge, annual ryegrass escapes can be controlled with full rates of SelectMax, Poast Plus or
Fusilade DX.
b. Use fertilizer, surfactant, crop oil as label-directed. Less effective in cold temps.
The use of seed blends for annual ryegrass cover cropping may not be the best idea. Here’s why:
Each variety of annual ryegrass has certain characteristics for growth, including how quickly it comes out of dormancy in the spring. And there’s a potential problem with that: if you spray the annual ryegrass with glyphosate when the grass is still dormant, none of the herbicide will be absorbed by the dormant plants. Thus, while the application may kill the actively-growing annual ryegrass varieties, those varieties still lying dormant won’t be affected.
There are a couple ways to deal with this issue. The first is to plant only one variety, one that has been tested for the Midwest and has the capability to stand up to harsher winter weather. When applying glyphosate to a single variety, there won’t be any difference in the time the entire cover crop field comes out of dormancy.
If you’re facing this spring with a field of annual ryegrass blend, you must be more vigilant about the burndown. The best bet, if weather cooperates, is to give the entire cover crop an extra 5 – 7 days to come out of dormancy. It’s a bit tricky to tell what’s an actively growing plant, so ask your crop consultant if you have doubts. But, with an extra week before burndown, you will likely be spraying plants that have all come out of dormancy.
Sometimes, after spraying annual ryegrass, it appears that the job has been done…the grass looks brown and dead. But be watchful; sometimes the kill hasn’t been complete and new growth can occur. Scout your field in the week or so after the first glyphosate application and see if it’s completely killed. If not, a second application of herbicide will be needed.
For more information about the fine points of burndown, check out the handy one-page reference on the General Information page in this blog section, for today’s date. Otherwise, you can also check out the same information on the annual ryegrass cover crop website. (News releases 2013 – Annual Ryegrass Control)
Back in the mid to late 1980s, Dan Towery got enthusiastic about cover crops. “Mainly, we were interested in reducing erosion but we were also looking at nitrogen fixation properties that could benefit corn planted into the residue,” he said.
But then, in the summer of 1988, the drought was much like it was this past summer (2012), and as Towery recalls, the results of “not knowing enough about cover crops” created a multiplier effect in the drought’s impact.”In order to give the hairy vetch the maximum time in the ground, to maximize the nitrogen fixation, farmers left the cover crop in the field until the 3rd week of May, when normal corn planting is the 3rd week of April.
“The vetch sucked too much moisture from the ground and the drought was made worse because of that decision,” Towery said. I said then: ‘I’m not promoting cover crops anymore!'”
But times and attitudes changed with the addition of annual ryegrass as a cover crop alternative in the early 90s.By the late 90s, Towery was working at the Conservation Tillage Information Center, promoting no-till mostly. Early results from Mike Plumer’s work with farmers in Illinois were producing promising results with annual ryegrass.
It wasn’t long before Towery was a believer again. In fact, he was an advisor working with the Nature Conservancy on a watershed enhancement project in Tippecanoe County, Indiana, where farmers were paid to use annual ryegrass to prevent field runoff.
“Look at the change in acceptance since then,” Towery said. “From a time where we paid farmers $500 to plant 10 acres of cover crops (1998) to now, when we’re experiencing a shortage of annual ryegrass and other cover crop seed, because of the demand.”
Towery said that education has bee a key element in the popularity of cover crops. “And, an important element continues to be the caution about use of cover crops….you have to be willing to be a good manager of the cover crop, no matter which one you choose.”
The name “rye” in both cover crops is confusing. Annual ryegrass is a grass; Cereal rye is a grain, more like wheat.
Both are used for cover crops and forage.
Here are some basic differences, with the most distinctive in bold:
1. Annual Ryegrass 2. Cereal Rye
Seed size/weight – very small (26 lb/bu) larger (56 lb/bu)
Plant date – varies, but late Aug/early Sept. best can be planted later Sept.
Seeding rate – drill: 12 – 17 lb/ac; aerial: 25 lb/ac drill: 45 lb/ac.
Winterkill – med. risk, less with 40 days fall growth and snow cover no
Deep rooting – yes, to 60 inches over a few years not as deep, 24 – 36 inches
Top growth – 10 ” to 12″ in spring, before burndown 20″ at burndown, can get to 72″
Nitrogen – sequesters N; releases N after burndown sequesters N; too much in stalks
Management – care in burndown; no volunteers! easy kill; careful w/ over growth
Allelopathic – no yes, with certain crop seeds
Cost – less $/ac. because of low cost/# and fewer #/ac. higher cost/# and more #/ac
The half-inch or so of rain in the Midwest this week has sprouted spirits, although with more warm weather forecast, the prospect for a reversal of fortunes on most corn crops is slim. The worst drought in more than 50 years has farmers mowing starved and stunted corn for sileage and bracing for similar hits with soybeans. (Make sure to check the nitrate levels in the corn stalks before saving it…too high a nitrate level can be fatal to livestock.) Even those able to salvage a corn crop this year will see vastly reduced yields.
Purdue’s Extension forage specialist Keith Johnson today recommended planting annual ryegrass, or another forage crop such as spring oat or forage turnip. Seeded early enough (August), farmers could get a grazing off the grass this fall, as well as next spring. Ryegrass would normally have a better chance of wintering over than oats or turnips.
Perhaps the only “silver lining” in the drought news is that there’s probably a lot of residual fertility in the soil that can be saved by planting a late summer cover crop, according to Nick Bowers, a seed grower in Oregon’s Willamette Valley. The good news with annual ryegrass: it’s inexpensive, it’s a scavenger of excess N in the soil and, even if it doesn’t germinate this fall, it will sprout next spring. If normal rainfall picks up, aerial seeding will be adequate, but drilling is otherwise advised. For more on seeding, check out this page.
Looking for another silver lining? Iowa State University climatologist Owen Taylor said it appears that this weather pattern – similar to 1956 and 1988 – comes in 20 year cycles. It appears, Taylor said, that we’re headed back to a “normal” pattern with an El Nino forming. Keep your fingers crossed.
All that corn in the field, dying. And with it, the prospect of additional losses of nitrogen fertilizer. If fields are mowed, or plowed under, in the wake of no-show corn, what happens to the nitrogen this fall, when the rains come? Leached out, poured into streams and rivers, sent to the already toxic Gulf of Mexico.
Cover crops, like annual ryegrass, prevent erosion. Just as importantly, they sequester nitrogen, acquiring what’s been left in the soil (normally 100-200 pounds/acre) and make much of it available next July, when maturing corn is looking for a boost.
Economically strapped farmers may be loathe to invest in cover crop seed for the fall when their insurance checks are still pending. Even more so for those without insurance. But if they’re going to plant corn next year, a cover crop this winter will be a huge asset next year. Even without a return on their corn investment this year, planting a cover crop can prevent further losses to erosion, while storing nitrogen for the crop next July and building soil more tolerant of drought.
Drought-stricken corn field: June 16 (left) and July 2 (right) – Robertson Farm, Benton, IL
Annual ryegrass, planted this fall (Aug. and early Sept), will send roots down to five feet in no-till acres, breaking up compaction and mining nutrients in deeper soil. Next spring, the nitrogen-rich cover crop will be killed before planting corn, and can give back as much as 70 percent of the stored nitrogen to maturing corn plants. Meanwhile, the deep roots of annual ryegrass become part of the growth of organic matter in healthy soil, even as corn roots grow past to reach deeper moisture in a dry year.
More info: www.ryegrasscovercrop.com
Contact: Dan Towery – IN agronomist, educator, former NRCS staffer: 765-490-0197.