This past week was beautiful! We saw more recovery on frost-damaged plants and it allowed for a lot of post-herbicide spraying. A question I kept receiving was how long to wait to spray crops that were frost damaged. Some labels will say to wait 48-72 hours before applying a herbicide while others don’t give a time, they just mention that injury to the crop can occur under specific temperatures or when plants are under stress. How I answered based on what we have recommended in the past is for any type of adverse weather event impacting crops (hail, frost, etc.), wait at least 3-5 days based on the label or until one starts to see plant regrowth of both the crop and the weeds. We would say the same for anyone who unfortunately experienced hail damage this weekend.
Interseeded Cover Crops: This past week was also a busy one for our team interseeding cover crops into V3-V4 corn. We are currently in the third year of a partnership between our farmer cooperators, The Nature Conservancy, Nebraska Extension, UBBNRD, and Kellogg’s. A couple cooperators are in the 4th year. The goals for planting cover crops into early season corn and soybean include reducing nitrogen inputs, weed control, improving soil health, increasing diversity, and providing forage for livestock. We’ve successfully achieved cover crop establishment and season long growth, covers that survived after harvest and survived into the spring to various extents in all years of the study. In the on-farm research locations from 2019-2021, the interseeded cover crop yielded less in 5 of the 12 site-years but yield was not impacted in the others. In 2021, there was no yield difference between the interseeded cover crop and check strips when seeded into soybean at two locations. Yields in 2020 and 2021 were impacted in some fields due to the July 9th windstorm in both years which opened up the canopy producing greater cover crop biomass.
Biomass samples taken in late September pre-harvest and pre-frost has ranged from 97 lb/ac to 2192 lb/ac. These are field averages as individual reps were over 4000 lb/ac in severely wind damaged fields. Additional growth was achieved after harvest but not collected. Biomass samples for nitrogen content taken in 2021 ranged from 5-200 lb N /ac. Beginning soil health assessments were taken the first year of the study and will be completed in September of 2022 for comparison.
We’ve also learned a lot about herbicide interactions with cover crops; they are fairly resilient. For the corn locations, we’ve went with a full PRE herbicide (generic Lexar, Callisto, Acuron…have not used Resicore) and then for POST, within 3 days either direction of interseeding using Roundup, Liberty, and sometimes dicamba with no impacts to the covers that we interseed. We have also had success using ½ rate of Lexar or Callisto at least 1.5 weeks prior to interseeding. The covers were scraggly, but they did come through it. We have never used a residual on the corn we interseed, but using a Group 15 was an option once the covers emerged and got up about an inch to provide residual if the guys wanted it.
For the soybeans, if a full PRE was applied at least 3 weeks prior to interseeding, we didn’t worry about it (which was the case in 2021). For POST, we just used Roundup and either Liberty or Dicamba within 3 days either direction of interseeding with again, the thought of a Group 15 if needed for residual once the covers were 1″ tall. In soybean, we interseeded 10 lb/ac red clover with 20 lb/ac of wheat. The field we interseeded at emergence had red clover survive the entire growing season, through harvest, and was growing this spring for the successive corn crop. It was unexpected and gave us insight into another way of potentially establishing a perennial crop for nitrogen. It ended up being killed out by the corn herbicide, but is something we’re repeating in different ways in 2022.
Regarding species that we feel are most successful in the corn, we like buckwheat, iron and clay cowpeas, clovers (red and sweet), brassicas such as collards and radishes, forage soybean, annual and Italian ryegrass. We’ve consistently seen sweetclover and the ryegrasses survive the winter into the spring. Depending on the year, we’ve also seen red clover and hairy vetch survive the winter. We’ve learned much more that I don’t have room for here. If you’re interested in learning more, be watching for our articles at cropwatch.unl.edu. Also, save June 30th for a potential Interseeding Cover Crop Driving Tour.
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.
I’ve so greatly appreciated the discussions and learning opportunities at meetings this past winter! We have one final cover crop meeting this Friday, Feb. 25 from 10-Noon at the 4-H Building in York. The topic is discussing the economics of cover crops. I’m often asked about this and have ideas, but don’t have answers, so am seeking a discussion around it. We know grazing often is the one way (not always, but often) where cover crops will pay. Looking forward to a deeper discussion on additional ways to look at economics of cover crops, such as assigning a dollar value to any soil changes over time. Please join us if you’re interested!
Estate Planning Workshop March 8: We’re excited to offer an estate planning workshop for farmers and ranchers from 1:30-4:00 p.m. on March 8 at the Seward County Extension Office (322 S. 14th St. in Seward). My colleague, Allan Vyhnalek, an extension educator for farm and ranch transition and succession, will offer tools and strategies to effectively plan, start and complete estate plans, offer background on common mistakes during the process, and highlight essential considerations for creating and carrying out estate and succession plans.
He also asked Tom Fehringer, an attorney based in Columbus, to present during the workshop. Fehringer specializes in estate planning, business planning and trust administration, among other areas of practice. It’s just a great opportunity to learn more and ask questions (especially of an attorney) for free! Please RSVP by March 7th at 402-643-2981.
K-Junction Solar Project Public Meeting Feb. 24: EDF Renewables is inviting the public to a meeting to learn more about the K-Junction Solar Project on Thursday, Feb. 24 from 5:00-7:30 p.m. at the Stone Creek Event Center in McCool Junction. Food and beverages will be provided.
Results of Xyway™ LFR® Fungicide in Furrow: Last week at the on-farm research update, three area farmers and I presented the results of our on-farm research Xyway™ LFR® studies. This fungicide, applied at planting, translocates within the plant providing disease protection for a period of time. In 2021, Xyway™ LFR® was tested at 8 on-farm locations in Buffalo, Hall, York, and Seward counties. Emergence counts taken at 4 locations in Buffalo/Hall counties showed better emergence with Xyway in one of the locations and slower emergence with Xyway in the other three locations. Early season stand counts were taken at all 8 locations. Of these, one location showed better stand with Xyway compared to the check, two showed less stand with Xyway, and the others showed no differences. Three of the 8 locations showed a yield reduction with Xyway compared to the check while the other five locations showed no difference. Half of the locations showed reduced profitability while there was no difference in the other half. At the two York locations, I also did disease ratings. In spite of it being a low-disease year, in one of the two locations, Xyway reduced gray leaf spot pressure on the plants compared to the check. At neither location was there a difference in overall southern rust severity. In general, the growers who tried this felt it was helpful from the standpoint their fields are near towns or powerlines where it’s difficult for arial applications. FMC recommended during the meeting to move the Xyway™ LFR® product away from the seed for those trying it in 2022.
Our Crop Science Investigation Youth (CSI) group worked with Jerry and Brian Stahr on their Xyway study as part of the Nebraska Corn Board’s Innovative Youth Challenge. It was a great way for youth to utilize the scientific method while learning about crop scouting and participating in on-farm research! The youth won first place and share their results in the following video: https://youtu.be/B87xqr0pWMk. If you know of youth interested in science and plants who may want to join us for CSI, please let me know! We meet monthly throughout the year. Next meeting is Mar. 15.
With the challenge of growing cover crops, particularly after corn harvest, interest in interseeding cover crops into living corn and soybean has increased in recent years. Goals for doing so include using the cover to: grow nitrogen for the crop, remove excess nitrogen (in the case of seed corn), aid in weed and erosion control, increase biodiversity, determine any soil health benefits, and desire for fall biomass for grazing. Some are also concerned about increasing regulation and wanting to figure things out ahead of the curve. Planning is key when it comes to interseeding cover crop into corn or soybean. Planning needs to include the goal of why interseed, the cover crop species interseeded, how the cover will be interseeded, the corn/soybean crop development stage for interseeding, and the herbicide program used.
A few years ago, we wrote an article sharing what was known about interseeding cover crops. The following is information we’ve learned as an interseeding project between The Nature Conservancy, Upper Big Blue NRD, Nebraska Extension, 11 farmers, NRCS, and Kellogg’s.
Timing: In corn, we’d recommend aiming for V4 (four leaf collars). V5-V6 is almost too late in years where canopy closure occurs quickly. The literature says there’s no yield loss after V2. For soybean, aerial interseeding around senescence (leaves turning yellow) is one option. From plots interseeded at V4 in 2020, we felt that was almost too late for aiding establishment. This year we will be trying at planting through V2.
Species: Penn State has a mix that’s considered the interseeding standard; it includes annual ryegrass, red clover, and hairy vetch. From the 12 species mixes we tried, the annual ryegrass, vetch, red clover all survived and were growing this spring. Thus, most likely why it’s considered the standard.
In corn, we’ve tried multispecies mixes because of the growers’ and partners’ goals and testing what came through different herbicide programs. We found the first species to emerge were the buckwheat and cowpeas. The farmers liked the species that provided more of an understory like the annual and Italian ryegrass, collards and other brassicas, and buckwheat. Cowpeas grew up to the corn tassels and provided the greatest biomass. Most of the species went to seed. Cowpeas, forage soybeans, and sweet clover were fixing nitrogen in season.
For diversity, the flax and buckwheat upon flowering drew many beneficial insects to the field. Pests like grasshoppers ate the covers in the interseeded strips and left the corn alone from what I observed.
In soybean, wheat was planted in the soybean management field day trials last year with some success. This year we’re considering wheat + red clover for the fields that will be interseeded from planting through V2.
Herbicide Programs: This is the difficult part. I think ideally (and I’m unsure if this is even realistic yet), a cover between rows aiding in weed control, adding nitrogen, providing fall biomass, and regrowing the following spring to aid in weed control again with only needing to add herbicide in a band, would be pretty cool.
In the wet year of 2019, Callisto-type (Group 27) products did their job and kept re-activating. This led to covers dying in one field. So in 2020, I suggested no residuals in post- apps. The guys went with me on this with most doing a pre- with residual followed by a post- of only glyphosate or Liberty prior to interseeding. The July 9th, 2020 windstorm causing plants to greensnap and/or bend caused problems with the canopy opening up and weed control in addition to biomass growth became a problem in these fields in competing with the corn crop. I was just sick about this and the guys extended much grace to me.
This year, for corn, some guys are sticking with last year’s program because it worked well for them, particularly in no-till with heavy residue. Another thing some may try is to apply a pre- with residual, interseed at V4 and then upon 1-2” growth of the covers, apply Dual II Magnum or Outlook (no grazing restriction with Outlook) to provide residual to aid in weed suppression. One farmer who applied generic Lexar pre-plant in some fields and did split app in others in 2020, still saw cover crop growth and emergence from the split applied. The cover crop growth in the split-applied was just stunted and thin compared to the fields where he applied the full rate pre-. He’s testing herbicide programs this year.
For soybean, there’s even more risk. For those who wish to plant and interseed at the same time, we’re trying a burndown immediately prior to interseeding (if they hadn’t applied an early pre- already), allowing the cover to get 1-2” tall and then go with a Group 15 chemistry. The other option we’re trying is going with their pre- with residual followed by interseeding at V2 and application of Group 15 herbicide after cover reaches 1-2” of growth. We also have guys who are planting soybean green into rye and will try interseeding after rye termination. We have no idea how all this will work and if others have ideas, please feel free to share! Next week I’ll share the yield and biomass results from the past few years.
The above pics were post-harvest. The covers showed good at that time still but they seemed to disappear pretty fast upon more hard frosts.
The above pictures were taken in March 2021 of spring growth. Annual ryegrass, hairy vetch, red clover, and collards survived the winter. As time went on, one could easily ‘row’ where the covers were interseeded in June 2020. The taproots on the red clover were extra impressive to me! Also, pretty much always saw earthworms when I dug up one of these plants.
Cold Weather and Livestock: This week I found gratitude time and again for a warm home. Thinking of those who haven’t been as fortunate. Have also thought about our livestock producers taking care of animals. In the unfortunate event of livestock losses, please document/take photos in the event of any disaster declarations for livestock indemnity payments (LIP).
Crop/Livestock Systems On-Farm Research Study: At last week’s cover crop and soil health conference, Ken Herz shared on his family’s on-farm research study. I’m so proud of and grateful to the entire Herz family for their partnership in this study and for the focus on the economics of an entire system! This study was designed with a system’s perspective incorporating crops, cattle, cover crops in a way that fit many operations in a non-irrigated setting. Their goals were to increase soil organic matter and ultimately determine yield and economics of the entire system. The crop rotation is Wheat (with cover crop planted into stubble after harvest), Corn, Soybean. Cattle graze the cover crop in the winter and also graze the corn residue. No-till wheat prior to corn for increased moisture saving and yield is common in this part of the State as is planting a cover crop into wheat stubble for grazing. The questions I hear include:
1-What moisture and potential yield am I giving up to the successive corn crop if I plant a cover crop into my wheat stubble?
2-If there’s a yield loss in the successive corn crop, do the economics of grazing the cover crop offset that loss?
We had three treatments and two locations (Location 1 had a cool-season cover crop and Location 2 had a warm-season one). The treatments are: ungrazed wheat stubble, ungrazed cover crop, and grazed cover crop. We’ve collected soil property, moisture, nutrient, and health data; yield and moisture of each crop; cover crop biomass; grazing days; and economics.
Location 1 in Nuckolls county began in 2016 with a cool season cover crop planted after wheat was harvested and manure applied. Three-year analysis showed no difference in soil physical properties (bulk density and compaction) amongst treatments. There was greater total microbial and fungal biomass in the grazed cover crop treatment (indicators of improved soil health). Interestingly, the ungrazed wheat stubble is the most economical treatment at this location. Reasons: cost of hauling water for grazing, numerically higher yields in the ungrazed wheat stubble, variable biomass in cool season cover, and a large yield hit to the 2018 soybeans in the grazed cover crop treatment during a dry year. In 2018, to the line there was a stress difference in the soybeans and that treatment read drier via soil moisture sensors. They’ve been conservative with grazing so at the time we couldn’t explain it. In taking soil health tests in year 3, we realized how greatly the microbial biomass had increased where cattle grazed. Our hypothesis is microbes broke down the remaining residue exposing soil to more evaporative losses resulting in less soil moisture and less yield for soybeans in the grazed treatment during a dry year. It’s now on our radar when grazing occurs to get cattle off even sooner to account for feeding the microbes too.
Location 2 in Webster county began in 2018 with a warm season cover crop. Over 4 tons of biomass allowing for 91 grazing days, not hauling water, and no successive crop yield differences all led to the grazed cover crop being the most economical treatment at this location.
Take home points: it’s important to add all the components when looking at economics. Grazed cover crop treatment at Location 1 would look better if we didn’t include the large cost of hauling water and if there was more cool season biomass allowing for more grazing days. The differing results at the two locations showed the influence of cover crop biomass and importance of including value of grazing; fencing/water/labor costs for livestock; cover crop costs; and successive crop yields in system economics. It’s easy to make assumptions that a certain practice is profitable! Location 1 will hopefully continue another 6 years switching the cool season cover crop to a warm season one to compare economics on the same field. We’re curious if the warm season cover will increase biomass and grazing days enough to outweigh the water hauling costs and show a benefit to the grazed cover crop treatment, or if the ungrazed wheat stubble will remain the most economical for this field location.
Regarding cover crop economics, it could be helpful to determine a consistent way for assessing a dollar value for potential benefits such as aiding in weed and erosion control, nutrient uptake, etc. This may aid conversations with landlords and lenders for those desirous to try them. Without livestock value, currently on paper, there’s really only costs.
(End of news column. Photos below are additional information.)
This time of year transitions to winter programming for me. The past few weeks I’ve mostly talked about cover crop results we’ve received from our on-farm research studies. I’m pretty passionate about on-farm research! On-farm research allows us to study topics we often wouldn’t receive funding for, with minimal monetary investment while conducting them on growers’ farms. It wouldn’t be possible without our grower cooperators and I’m so grateful for them!
We have an on-farm research database at: http://resultsfinder.unl.edu/ where you can click on a county or enter a keyword to search for various studies. It’s kind of picky on the wording, but it’s still a nice tool. I used this to compare cash crops planted into either cereal rye or cover crop mix for 1 year or for 3 years. Results can also be viewed via tables on my blog at: jenreesources.com.
One Year Studies: From 2008-2018, there were 7 studies in which corn or soybean was planted into cereal rye. They all showed either no yield difference or yield loss when the cash crop was planted into the cereal rye regardless of terminating pre- or post-planting. In 3 studies conducted in Clay, Franklin, and Phelps counties in 2014, either non-irrigated corn or wheat was planted into a cover crop mix. They all showed yield loss and moisture was anticipated to be a limiting factor, but no moisture sensors were used in the studies.
Three Year Studies: In three Saunders county locations where they planted cereal rye after harvest on the same strips for three successive years, there was either no yield difference or a yield increase in year three when the cash crop was planted into the cereal rye. We also have a long term study in Nuckolls county and will share more on that in an upcoming column.
We encourage growers to conduct studies more than one year where feasible. It’s especially important when looking at studies that have longer term implications to soil to maintain studies in the same location over time. Maybe some of you have tried a cover crop once but didn’t see positive yield results after year one; perhaps yield results would be different over time? The on-farm research studies summarized here don’t go into enough detail to specify why yields were the same or improved in the three studies in year three. During different meetings, some also asked about nitrogen tie-up in the cover contributing to yield loss. There are other studies showing addition of nitrogen at planting can reduce yield loss impacts due to nitrogen tie-up. Where we had information about nitrogen applied at planting, I added this to the tables on my blog. Ultimately, there wasn’t consistency in rates applied nor improved yield in all cases with these studies.
Farm Bill Meeting York Dec. 6: A reminder of the Farm Bill Meeting to be held at the Cornerstone Event Center at the Fairgrounds in York from 9 a.m.-Noon on Dec. 6. Please RSVP at: go.unl.edu/farmbill to select this or any other location. This helps us prepare and helps save time at the door during registration. If you prefer not to RSVP via computer, you can call your local Extension or FSA office and we will get you registered.
Nebraska Soybean Day and Machinery Expo Dec. 19 will assist soybean producers in planning for next year’s growing season. The expo will be in the pavilion at the Saunders County Fairgrounds in Wahoo. The Saunders County Soybean Growers Organization will be collecting non-perishable food and monetary donations for the Saunders County Food Bank backpack program. Complimentary noon lunch will be served. Registration is available the day of the expo at the door and there is no registration fee.
The event opens with coffee, doughnuts and the opportunity to view equipment and exhibitor booths at 8:30 a.m. Program begins at 9:10 a.m. Topics include: A New Marketing Tool for Soybean Growers-The Role of Harvest Moisture (Cory Walters, UNL); Decision Making in Uncertain Times (Richard Preston, Preston Farms Kentucky); Managing Soybean Diseases with Fungicides (Daren Mueller, ISU); Managing Waterhemp (Chris Proctor, UNL); Soybean Gall Midge (Justin McMechan, UNL); and Nebraska Soybean Checkoff Update and Association Information.
*End of Column. Cover Crop Tables Below.
Table 1: Corn or Soybean Planted into Cereal Rye Cover. One year studies. Yield values with the same letter are not significantly different at a 90% confidence level (for each individual study).
Table 2: Corn or Wheat Planted into Cover Crop Mix. One year studies. Yield values with the same letter are not significantly different at a 90% confidence level (for each individual study).
Table 3: Three year studies utilizing cereal rye as cover crop in same strips over time. Yield values with the same letter are not significantly different at a 90% confidence level (for each individual study).
Reminder of South Central Ag Lab Field Day August 29th from 8:25 a.m.-4 p.m. (Registration at 8 a.m.)! 10.5 CCA credits have been applied for. More information at: https://go.unl.edu/zvwx
Crop Update: The rain last weekend was a blessing to many. It along with cooler temperatures has allowed for deeper kernels and delayed corn maturity. In fact, if we were to stay at the high temperatures we were experiencing, the Hybrid Maize model was predicting maturity in our area anywhere from 1-3 weeks early. Now, it’s mostly just predicting one week early (for anything that isn’t already mature). It also is showing above average yields for non-irrigated corn where drought-stress and hail weren’t a factor. Irrigated yields are showing near average according to the model for most fields in the area. You can see all the graphs and read more in this week’s CropWatch at http://cropwatch.unl.edu. Corn has reached black layer in many of the hail damaged fields I’ve looked at and some of the drought-stressed fields will begin harvest in a few weeks. The rain also greatly helped the soybeans, even in drought-stressed areas.
However, the rain also greatly increased stalk rot in fields, particularly in hail damaged ones. We weren’t seeing a large amount of mold in the first 7-10 days post-hail in hail damaged fields that were late dough to early dent. Now, nearly 21 days later, we’re seeing fungal growth increasing with the moisture and humidity within the husks of corn ears. It will be very important to check your fields to determine worst ones and worst areas of fields regarding stalk rot and kernel damage. Those areas should be harvested first if they’re being taken for grain and we’re recommending to fill any contracts with grain from those areas first. In checking for stalk rot, I prefer a ‘pinch test’ compared to a ‘push test’. With the pinch test, take your thumb and first finger and pinch the stalk internode that occurs between the lower nodes above the soil line. Do this for 20 plants in an area and get a percentage for those that crush. Then do this for several areas of your field. This gives you an indication of the level of stalk rot for your field and worst affected areas.
Cover Crops: With recent crop insurance determinations on these damaged fields, I’ve received an increasing number of questions regarding cover crop use. We’re already seeing weeds germinating in these fields due to open canopies, so weed control is one considerations for using a cover crop right now. Other reasons expressed have been for excess nitrogen uptake and also for a forage option. Dr. Mary Drewnoski, Extension Beef Nutritionist, Dr. Daren Redfearn, Extension Forage Specialist, and I talked through options to consider right now.
Always check with your crop insurance agent before seeding a cover crop into hail-damaged fields. It’s also important to check replant, forage and grazing restrictions regarding the herbicide program you used and any delay necessary before seeding a cover crop and any forage restrictions to grazing a cover crop. (See Replant Options and Herbicide Rotation Restrictions and Forage, Feed, and Grazing Restrictions for Row Crop Herbicides, both excerpted from the 2018 Guide for Weed, Disease, and Insect Management in Nebraska, EC130.)
In general, we’re at an interesting time for making cover crop decisions. Typically we use September 1 as the divider between planting small grains such as oats that will winterkill and winter hardy cereals such as rye or triticale (planted after September 1). Even with brassicas such as turnips, collards, or rapeseed, we’d recommend the cutoff for seeding to be within the next two weeks. Because of this time frame, mixes may be beneficial because they’ll take advantage of whatever weather we have for the rest of the season. Simple, inexpensive mixes may allow for at least something to become successfully established. So, for those looking at something to winterkill, oats could be planted yet this week as could a mix of oats and brassicas. However, after this week, we’d be looking at either adding something like rye or triticale to the mix or just switching to the more winter-hardy small grains. And honestly, while it isn’t mentioned in the table, if a person’s goal is cover the ground for weed management, bin-run wheat is also an inexpensive option. Your local seed supplier can provide seeding rates for cover crop options and we’ve provided a table with these options, depending on your goals, at http://cropwatch.unl.edu.
Yellow or red tops in corn plants: For a month now, we’ve observed yellow tops in corn plants. Plants that contain ears and are turning yellow from the top to the middle of the plant can be occurring because of anthracnose top dieback or another disorder called ‘top leaf death or dieback in corn‘. Some plants with this discoloration truly do have anthracnose spores present on the stalk and sheaths. However, there have been other situations where I couldn’t find the presence of anthracnose spores. In those situations, the plants were often on compacted areas of field edges, always had a nice ear on the plant, and sometimes had tillers as well. Dr. Bob Nielsen at Purdue mentioned they had found what’s called ‘top leaf death’ in corn in situations where they experienced more drought or heat stress. Those plants had leaf discoloration similar to anthracnose top dieback, but without the presence of the spores. So, for those situations where I’m not finding anthracnose spores, I’m calling it this top leaf death disorder. You can read more about this at: https://www.agry.purdue.edu/ext/corn/news/timeless/topleafdeath.html.
|COVER CROP||USE/GOAL||WHEN TO PLANT||HOW TO SEED||RATE
|OATS||Weed Management||By Sept. 1||Drill best. Can fly on.||30-40 lbs||*|
|OATS/RYE MIX||Weed Management||By Sept. 1||Drill best. Can fly on.||30 lbs each||*|
|OATS||Forage||By Sept. 1||Drill best. Can fly on.||80-90 lbs||*|
|OAT/RYE MIX||Forage||By Sept. 1||Drill best. Can fly on.||30-40 lbs of rye and 50-60 lbs oats||*|
|BRASSICAS (TURNIP, COLLARD, RAPESEED)-NOT OILSEED RADISHES||Cover ground, forage, nitrogen uptake||By Sept. 1||Fly on for quicker establishment.||5-6 lbs||—|
|RYE||Weed management, cover ground, forage, nitrogen uptake||After Sept. 1||Drill best. Can fly on.||50-60 lbs||*|
|*If adding a brassica to any of these small grain options, only 2 lb/ac is needed. Rapeseed isn’t as well known, but is an inexpensive and good option for consideration.|
Crop Update: Wheat is mostly in various stages of heading through pollination in this part of the State. The wheat scab risk prediction model (http://www.wheatscab.psu.edu/) was forecasting higher potential for scab in portions of Nebraska last week with a relax in the model this week due to higher temperatures and no moisture. Please keep an eye on your growth stages, the weather, and the model for risk of scab in your wheat.
Don’t have too much in the way of corn and soybean updates other than it’s good to see guys finishing planting and getting herbicide applications down. Waterhemp and palmer range in size from emergence to 4 inches from what I was seeing this past week.
Also a reminder to install irrigation scheduling equipment soon. It’s always easier to install earlier than when plants get larger! Check out this week’s CropWatch article at https://go.unl.edu/n0u0 which shares additional information about ET gage sites; reminders and tips for installing ET gages and watermark sensors.
Wheat and Field Pea Field Days: There are 11 upcoming wheat field days throughout the State, many of them coupled with field pea/pulse/cover crop field days as well. During the field visits participants will be able to learn more about different varieties of wheat, field peas, chickpeas and forages. Depending on the location, field visits will also include demonstrations of other specialty crops (lentils, winter canola, forages, cover crops) and effects that different agronomic practices (planting dates, seeding rates, fertilizer management, etc.) have on crop yield and yield quality.
Besides field visits, the field days will feature indoor sessions with a free lunch, a 30-minute networking session, and brief research updates. Networking sessions will allow participants to meet with seed, processing, and marketing businesses critical to pulse cop industry development in Nebraska. The research updates will include: Production and marketing of pulse crops, Incorporating cover crops in wheat and field pea cropping systems, and Wheat production – management for higher yield and grain protein. Area dates/locations are listed below and all flyers with additional information can be viewed at: https://go.unl.edu/vto8.
- May 30: Wheat Field Day, 6:30 p.m. at Fairbury, RSVP firstname.lastname@example.org
- June 12: Wheat and Pulse Crops, 9 a.m. at the UNL ENREC near Mead, RSVP email@example.com
- June 18: Wheat and Pulse Crops, 9 a.m. near Callaway and at North Platte (UNL WCREC), RSVP firstname.lastname@example.org
- June 19: Wheat and Pulse Crops, 8:30 a.m. near Grant (UNL Stumpf Wheat Center), RSVP email@example.com
- June 20: Wheat and Pulse Crops, 9 a.m. near Alma and Bladen RSVP firstname.lastname@example.org
Nebraska Field Pea Field Days are free, thanks to sponsorship by the Sustainable Agriculture and Research Education (SARE) in Nebraska, the Nebraska Environmental Trust, and the pulse crops seed and processing industry.
South Central Ag Lab (SCAL) Weed Science and Cover Crop Field Day: View demonstrations of new technologies and herbicides for weed control in corn, soybeans, and sorghum and effects of cover crops on soil health and pest management at the June 27 Weed Management and Cover Crops Field Day. It will be held at the South Central Ag Lab near Clay Center. The day begins with registration and rolls at 8 a.m., followed by weed management tours from 8:30 a.m. – noon, and cover crop demonstrations from 1 to 3 p.m. A free lunch will be served. In addition to the field demonstrations, Jim Specht, University of Nebraska-Lincoln professor emeritus, will presented on “Optimizing Soybean Planting Date, Seeding Rate, and Seeding Depth in Nebraska.” CCA credits will be available. Please pre-register at: https://agronomy.unl.edu/fieldday. The South Central Ag Lab is 4.5 miles west of the intersection of Hwy 14 south (to Clay Center) and Hwy 6 or 12.4 miles east of Hastings on Hwy 6. GPS coordinates: 40.57539, -98.13776.
- Comparison of Herbicide Programs for Weed Control in Soybean including Roundup Ready 2 Xtend and Liberty Link Soybean, Examples of spraying the wrong herbicide on wrong soybean herbicide-resistant cultivar, Weed removal at different growth stages and yield impacts, and Understanding multiple herbicide-resistant soybean herbicide programs.
- Comparison of Herbicide Programs for Weed Control in Corn including glyphosate and glufosinate-resistant corn in addition to several new corn herbicides, response of white and yellow popcorn to various herbicide chemistries and off-target movement, control of volunteer corn in Enlist Corn, and Weed Control and Crop Response in INZEN sorghum.
- An Overview of the Effects of Cover Crops on weed suppression, pests (particularly wheat stem maggot) and beneficial insects. Cover Crop Effects on Soil Health, including changes in soil microbial communities and soil physical properties with a focus on cover crop root biomass.
Hope you had a blessed Easter! The Wheat Stem Maggot in Cover Crop Webinar can now be viewed at: https://www.youtube.com/watch?v=XGjuzMlrjhQ&feature=youtu.be. The link for the survey mentioned in the webinar is no longer available but you are welcome to contact Dr. Justin McMechan for additional comments/questions. He goes through a number of insects to watch for and his ultimate message is to scout to determine termination timing.
Cover Crop Interseeding: A few weeks ago I attended the interseeding cover crops field day which had a really good attendance for March! For those of you considering this, I learned it’s best to start earlier than V6…consider V3 and if it’s wet, you have a better chance of actually getting interseeding accomplished by V6. This is year 3 of their study. The first year they used a spreader to seed the mixes. The second year they found utilizing insecticide boxes for the seeding when they cultivated worked the best. The third year they used a Hiniker inter-row seeder which they purchased.
Regarding mixes, most of them included annual ryegrass or cereal rye. There’s a Penn State mix (27# total of annual ryegrass, red clover, and hairy vetch) that has been successful in northern U.S. states. Very little cover was observable this spring, but from a photo provided, it appeared growth came on during corn senescence and after harvest last year. Fall biomass wasn’t measured last year which will hopefully be measured in the future to obtain more data on the success of the mixes. My take, if your goal is early spring grazing or early spring cover, I’m unsure that much can beat cereal rye, even if it was dormant seeded. If you’re looking for a way to get some cover established prior to corn harvest for either fall grazing or just fall soil cover, interseeding with a mix containing the annual ryegrass looked good from the pictures they showed. If you’re interested in any cover crop or other on-farm research studies this year, please let me know!
Tree Care Workshop: Trees are very valuable in our landscapes. They provide us with beauty, shade, oxygen, and better resale on our homes. These trees need our help to ensure they have healthy growth. When they have a disease or insect problem, it is up to us to manage those pests to help them live many years. On Wednesday, April 18th from 5:30-7 p.m. at the Fairgrounds in Clay Center, Nicole Stoner will teach us what to do with our trees. Nicole is a Horticulture Educator from Gage County. This tree program is $5.00 and will cover light refreshments and your educational materials. Nicole will cover watering, insect and disease problems, general care, and planting of trees. Please pre-register by April 13th with Nebraska Extension in Clay County by calling 402-762-3644 or emailing email@example.com.
Spring Affair Plant Sale: Spring Affair, the Midwest’s largest plant sale and gardening event, will be Saturday, April 28 at the Lancaster Event Center in Lincoln from 9 a.m. to 2 p.m. More than 700 different varieties of perennials, herbs, grasses, trees, shrubs and other plants will be available. They are selected for regional suitability, uniqueness, popular demand and provided by Bluebird Nursery, Inc., of Clarkson, Neb. It is sponsored by the Nebraska Statewide Arboretum as an educational tool, fundraising event and to promote regional plants. For information and inspiration, half hour plant talks will be offered at:
- 10:00 – “Nebraska Native Plants for Birds” by Jason St. Sauver, Spring Creek Prairie Audubon Center
- 11:00 – “Gardening 101: I’ve got my plants, now what?” by Justin Evertson, Green Infrastructure Coordinator for the Nebraska Statewide Arboretum
- 12:00 – “The Guilt-free Garden” by Mark Canney, Park Planner & Designer for Lincoln Parks & Recreation
Admission to the sale is free. The plant sale, presentations, educational booths and vendors of garden-related items are all in Pavilion I of the Lancaster Event Center with plenty of free parking. For more information, visit https://plantnebraska.org/spring-affair.
DriftWatch/BeeCheck: Nebraska Department of Ag (NDA) encourages pesticide applicators to check out DriftWatch/BeeCheck at http://driftwatch.org to minimize pesticide drift. It’s important for those with sensitive sites such as organic, bees, vegetables, grapes, etc. to add them to this website and important for all applicators to check this website for sensitive locations around our fields. Several states have been added to DriftWatch/BeeCheck in the last year and a few more are in the works, making it more beneficial to applicators working near the state line or those working in multiple states. FieldWatch, the company that manages DriftWatch/BeeCheck, now offers data subscriptions for obtaining data files for GIS maps or live stream data through several mapping software providers. It will be rolling out a new mobile app very soon, FieldCheck, for applicators who have registered as an applicator (which is free to do). You can also view the most recent edition of NDA’s Plant Health Protection Update at: https://us14.campaign-archive.com/home/?u=eb13611bfcca17410ce5c5f52&id=10756f8d33.