Nitrates and Grazing Forages: the fact that we haven’t had a hard frost is throwing a wrench into grazing covers. For those with cattle on cover crops, please be aware of the potential for nitrate and/or prussic acid poisoning with the light frosts. Nitrogen moves from the roots up the plant. When a frost occurs, nitrates accumulate in the plant, and, we had lighter frosts for several days in a row. For sorghum species where prussic acid poisoning is also of concern, we say to wait at least 5 days before returning animals back to the field after frost. And, for every light frost, the 5 day window resets until a hard freeze occurs (at 26F or lower). It’s been hard to find any recommendations regarding nitrate accumulations in brassicas after frost…and what happens to the nitrates after a frost. We know weathering in general reduces nitrate levels in plants by spring. Just advising to watch cattle with these light frosts-especially those in seed corn fields that had milo in corners.
A study conducted by Mary Lenz, grad student for Dr. Mary Drewnoski, found brassicas accumulate more nitrate than small grains, millet, sorghum/sudan grasses, or cover crop mixes, and that 48% of the brassica samples submitted to Ward Labs were considered “highly toxic” for nitrate levels compared to 20-28% of other cover crop species. Yet what’s interesting is how often fields in the “highly toxic” level (or with no testing) are grazed with no impacts. Dr. Mary Drewnoski has shared that brassicas and immature grasses are also high in energy and that cattle consuming diets high in energy can handle more nitrates. So, this may be why we thankfully don’t see more issues grazing turnips and radishes high in nitrate. She shared other factors for consideration are that cattle are selective and will graze the upper-most parts of plants first which are lower in nitrates, grazing animals eat more gradually than those receiving hay, and the high moisture forages that are grazed release nitrates at a slower rate than with dry forages like hay. Ways to reduce nitrate concerns when grazing include: turning out cattle full before grazing the covers, using lower risk cattle such as open cows and stockers (as pregnant cows have risk of abortion when fed forages high in nitrate), graze lowest nitrate fields first for adaptation, graze highest nitrate concentration fields lighter so not as much forage is removed, or there’s also the option of not grazing fields that are very high in nitrates.
Corn Nitrogen Calculator: For those desirous to calculate N rates utilizing different sources and prices, the UNL nitrogen calculator has been updated. Before, it didn’t allow for the prices we currently are experiencing and there’s been some updates to the manure credits. The UNL nitrogen equation itself has remained the same, and honestly, I still say it’s conservative. For example, the nitrogen credit from soybeans is 45 lbs/ac in the equation. However, on-farm research conducted in the mid-2000’s in this part of the State found a credit of 1 lb for every bushel up to 60 bu/ac was achievable in irrigated soybean.
To utilize the N calculator, go to: https://cropwatch.unl.edu/soils, scroll down to “Corn Nitrogen Recommendations Calculator” and download the excel spreadsheet. You will want to open the “October 2021” version. They’re currently working on an online calculator for the future.
A few questions I received this week: “How much yield loss should I expect if I reduce N rates?” and “With higher corn prices, how much profit is one giving up with lower yields due to lower N application?”. These are valid questions and ones every operation will have to determine for oneself. That’s where on-farm research is really helpful too.
We have lots of data through the years of comparing a grower base rate +/- 30 lbs. of nitrogen mostly showing no yield differences. Most of this data is from the 1990’s for this part of the State, with data from the past 10 years from other parts of the State. In 2020 and 2021, a grower conducted nitrogen rate studies in York and Hamilton counties using his rate +/- 50 lb N. As I’ve shared the results with growers with the above-mentioned questions, they’ve been surprised at the yields and profits. I’ve summarized the grower’s results at jenreesources.com and also showed the profit based on today’s fertilizer prices. There’s a few ways to approach this data. It shows minimal benefit to yield and profit for increasing nitrogen application above the grower’s rate. Thus, there may be opportunity this year for those who have been over-fertilizing for high yield goals to try cutting back. It also shows that yield is reduced to some extent by reducing N rate 50 lb/ac below what the grower’s rate typically would be; however, with today’s prices, profit may be comparable. We also have several farmers who are already doing a great job with fertilizer rate for their realistic yield goals, so there may not be room to cut back. Appreciate all the farmers conducting on-farm research so we have data to share to help in answering questions!
*Please overlook my formatting issues below. There are no links even though some of the wording keeps appearing in blue instead of black.
2020 York County Spring Anhydrous Nitrogen Rate on Corn
This study essentially showed what the previous studies had: that less nitrogen can be applied without hurting yield or net return. 50 lb/ac N above the grower rate resulted in reduced profit. Field yields were impacted by the July 9, 2020 wind storm. This study is sponsored in part by the UBBNRD.
|Pre-Plant||In-season||lbs N/bu grain||Yield||Marginal Net Return|
|110 lb N/ac spring NH3 (March)||25 lb N/ac as UAN May||0.73 C||184 A||$599.14 A ($849.30)|
|160 lb N/ac spring NH3 (March)||25 lb N/ac as UAN May||0.98 B||189 A||$600.38 A ($837.80)|
|210 lb N/ac spring NH3 (March)||25 lb N/ac as UAN May||1.23 A||191 A||$594.88 A ($810.70)|
*Values with the same letter are not statistically different at a 90% confidence level. Marginal net return based on $3.51/bu corn, $8/ac for the anhydrous application cost, $0.28/lb N as anhydrous, and $0.35/lb N as UAN. (Updated marginal net return using $5.20/bu corn, $0.75/lb N as anhydrous and $1/lb N as UAN.)
2020 Hamilton County Evaluating Nitrogen Rate and Timing on Corn
This study showed no difference in nitrogen timing nor rate on yield and showed less nitrogen can be applied without impacting yield. Yields were impacted by the July 9, 2020 windstorm. This study is sponsored in part by the UBBNRD.
|Pre-Plant||In-season||lbs N/bu grain||Yield||Marginal Net Return|
|180 lb N/ac Fall NH3||25 lb N/ac as UAN May||1.03 B||199 A||$629.85 A ($866.80)|
|230 lb N/ac Fall NH3||25 lb N/ac as UAN May||1.27 A||201 A||$625.49 A ($839.70)|
|180 lb N/ac Spring NH3||25 lb N/ac as UAN May||1.02 B||201 A||$638.30 A ($877.20)|
|230 lb N/ac Spring NH3||25 lb N/ac as UAN May||1.24 A||206 A||$641.70 A ($865.70)|
|120 lb/ac N Spring NH3||25 lb N/ac as UAN May|
60 lb N/ac side-dress V8
|1.00 B||205 A||$645.69 A ($880.00)|
|170 lb/ac N Spring NH3||25 lb N/ac as UAN May|
60 lb N/ac side-dress V8
|1.24 A||206 A||$633.50 A ($847.70)|
Values with the same letter are not significantly different at a 90% confidence level. Marginal net return based on $3.51 bu corn, $0.28/lb N as anhydrous ammonia, $8.00/ac for anhydrous application, $0.35/lb for UAN applied with herbicide or as a sidedress, and $3/ac for sidedress UAN application. (Updated marginal net return using $5.20/bu corn, $0.75/lb N as anhydrous, $8/ac for anhydrous application, $1/lb for UAN applied with herbicide or as sidedress, and $3/ac for sidedress UAN application.)
20% wind damage from July 9, 2021 storm. Updated marginal net return using $5.20/bu corn, $0.75/lb N as anhydrous shows essentially no difference in profit for any yield differences observed:
100 lb-N/ac: $1053.40
150 lb-N/ac: $1052.30
200 lb-N/ac: $1051.20
2021 York County Spring Anhydrous N Rate Study
20% wind damage from July 9, 2021 storm. Updated marginal net return using $5.20/bu corn, $0.75/lb N as anhydrous:
130 lb-N/ac: $900.90
180 lb-N/ac: $969.10
230 lb-N/ac: $924.70
2021 York County Timing by N Rate Study
Spring 140 lb/ac: 110 lb/ac N as anhydrous and 30 lb/ac N with herbicide
Spring 190 lb/ac: 160 lb/ac N as anhydrous and 30 lb/ac N with herbicide
Split 140 lb/ac: 50 lb/ac N as anhydrous, 30 lb/ac N with herbicide, and 60 lb/ac N sidedressed at V8
Split 190 lb/ac: 100 lb/ac N as anhydrous, 30 lb/ac N with herbicide, and 60 lb/ac N sidedressed at V8
This study is sponsored in part by the UBBNRD. Updated marginal net return using $5.20/bu corn, $0.75/lb N as anhydrous, $1/lb N as UAN and $8/ac for the sidedress UAN application:
140 lb/ac spring: $1109.50
190 lb/ac spring: $1077.20
140 lb/ac split: $1096.90
190 lb/ac split: $1054.20
It’s been a very nice fall with gorgeous colors on the trees the past month! It’s also hard to believe tomorrow is Nov. 1. While there’s a Nov. 1 date for fall anhydrous application in area NRDs, we also recommend watching soil temperatures and apply when soil temperatures are 50F or lower. This is because nitrifying bacteria slow due to the cool temperatures and by 40F, the process of nitrification is near zero. Nitrifying bacteria are ones that, through a biological process called nitrification, convert ammonium to nitrate. They multiply and complete this nitrogen conversion quickest in warmer soil temperatures (low to mid-80’s). The cooler weather this week will help continue to drive soil temperatures down. At time of writing this, they’re setting at 49F at the 4” depth for last week in the York area. You can view daily and weekly average soil temperatures at: https://cropwatch.unl.edu/soiltemperature. Also, a quick plug to consider an N rate study this coming year. It’s fairly easy to do…apply your current rate in one pass, compare that to 30 or 50 lbs. under the next pass, and alternate it across the field. For example, if you had a 16 row applicator and an 8 row combine, each harvest pass then becomes a comparison to the rate next to it (paired comparison) for on-farm research. You could also do 3 treatments comparing the same amount over and under your current rate using this protocol. A number of protocols have been updated at: https://cropwatch.unl.edu/farmresearch/extensionprotocols.
With cooler temps, it’s also important to safely graze frosted sorghum species. More info here: https://go.unl.edu/d8kv.
Young, Beginning, Small Farmer Symposium will be held Nov. 8 from 9 a.m.-4 p.m. at UNL’s East Campus Union in Lincoln. The event will also be livestreamed. There is no charge and lunch and parking will be provided. The event will be structured as a series of panel discussions. Audience members will hear from farmers who are getting started in both traditional and non-traditional operations. They’ll also hear about financial and risk management resources available to farmers as they grow their operations. To register or watch the livestream, go to: https://ianr.unl.edu/young-beginner-and-small-farmer-symposium.
Flyers for both the events I mention next are found at https://jenreesources.com. On November 8-11, there’s a Holistic Management Workshop held in different locations throughout the State. On November 12 is an opportunity for youth and families to hear about animal behavior from Dr. Temple Grandin at 10 a.m. at the Buffalo County Fairgrounds in Kearney. Dr. Grandin brings awareness about autism and its relation to animals. She also will be the keynote speaker for the Kids and Dreams Autism Conference: http://www.kidsanddreams.org/.
Crop Input and Cost of Production Workshops will be held Nov. 9-11 in Hastings, Beatrice and the Mead area, which includes a virtual option for producers from across the state to join. Crops and agricultural economics extension educators will cover the forces that are driving input costs and commodity prices, discuss fertilizer recommendations based on soil test results, and provide information on preparing cost of production budgets. Attendees are welcome to bring their latest soil tests. Registration is required at: 402-472-1742 or https://cap.unl.edu/crop-input-and-cost-production-workshop-registration. The workshops will be held from 2 to 4 p.m. at the following locations:
- Tuesday, Nov. 9 in Hastings at the Community Services Building on the Adams County Fairgrounds, 947 S. Baltimore Ave.
- Wednesday, Nov. 10 in Beatrice at the Gage County Extension Office, 1115 W. Scott St.
- Thursday, Nov. 11 near Mead at the Eastern Nebraska Research, Extension and Education Center, 1071 County Road G., Ithaca, Nebraska. (Face coverings required.) (Livestream option available for Nov. 11. Register here to receive the Zoom link.)
Cover Crop Grazing Conference will be held Nov. 16 at the Eastern Nebraska Research, Extension and Education Center near Mead. The conference kicks off with registration, refreshments and a trade show at 9 a.m. at the August N. Christenson Building. Educational programs are from 10 a.m.-3:30 p.m. and include a producer panel session, small group discussion and a live field demonstration. Featured presentations include “Early and Late Season Grazing of Cover Crops” with Dr. Mary Drewnoski and “2022 Cash Rent and Flex Lease Arrangements” presented by Jim Jansen. Registration is $10 and can be paid at the conference via cash or check. Please pre-register at: https://extension.unl.edu/statewide/enre/2021-cover-crop-grazing-conference/
Grateful for some rain! I know many were pushing and hoping to complete harvest before it, yet it’s so good to get some moisture and rest as well.
This week’s CropWatch at https://cropwatch.unl.edu shares several articles about considering nitrogen credits, prices, and cost of production for the 2022 growing season. The UNL budgets have been updated for 2022. A new tool called the Ag Budget Calculator is also available where the UNL budgets are already inputted into it and allow you to alter them to fit your operation. If you don’t already have a system for keeping track of your cost of production per acre, consider checking out the Ag Budget Calculator at: https://cap.unl.edu/abc.
A common conversation this week was around manure use for nutrient management. If a person has access to manure, it’s a great resource! It was interesting to me how many were uncertain about using it. Perhaps part of that is just understanding how nutrients are credited. In general, 70% of the phosphorus and 70-90% of potassium are available the first year. However, nitrogen availability varies more. An important piece to understand is that there is both ammonium nitrogen (from urine) and organic nitrogen (from feces) available in manure. The amount of nitrogen available the first year in the ammonium form depends on the animal source, liquid vs. solid manure, and if the manure is incorporated or not. The amount available from the organic component is determined by mineralization with additional being released in the second and third years. The following article shares on maximizing profitability of manure use: https://go.unl.edu/f946. The following NebGuide does a great job explaining how to determine the amount of crop available nutrients from manure the first through third years after application: https://go.unl.edu/2use.
Another common conversation was around nitrogen management in general…things like should a person switch nitrogen sources for their operations due to price differences between anhydrous and UAN and conversations around how many inputs seem to have to be locked in this time of year vs. can they wait. At the end of the day, each grower will have to determine these things for your own operations, but I’m willing to listen. Ultimately, for operations where you have specific goals you’re striving to achieve and have been in process of altering things through the years to achieve them, I’d encourage you to stay the course and not make drastic changes for one year. If you’ll sleep better at night trying some different things on a field or a few acres, then try them, but perhaps don’t throw out everything you’ve done to this point for one year. It’s anyone’s guess what next spring will bring. This could be a great year for you to consider testing different nutrient rates and/or timings on your farm when you may not have been comfortable doing so in the past. I’ve placed a few on-farm research protocols for consideration at jenreesources.com which can be altered for different application timings, N sources, and rates. There’s also a number of nutrient-management related protocols at: https://cropwatch.unl.edu/farmresearch/extensionprotocols. I realize many of you try things on your own farms. It’d be great for more growers to consider doing these types of studies via on-farm research as that helps all of us have more data that can be shared. I realize the protocols can look daunting, but for the most part, I think the farmers conducting on-farm research would agree they’re really not that complicated. Please contact me or your local Extension educator if you’re interested in any of these!
Lawn Care Fertilizer and Weed Control: Mid-September is the best time to apply fertilizer to cool season lawns. If fall fertilizer has not yet been applied, or a second application is to be made, only use fertilizers with fast release nitrogen sources and make the application before October 31. More information here: Rethinking Fall Fertilization, Nebraska Extension Turf iNfo.
As temperatures become colder, the process of herbicide movement and weed kill slows, but can still be effective as long as the weed has green leaves. Broadleaf weed control is most effective with spot treatments of herbicides applied during fall. When night temperatures begin to fall into the 30s, plants initiate carbohydrate movement into the root system. This increases the movement of herbicide into roots to increase weed kill. Combination herbicides are generally more successful than individual active ingredients in controlling perennial broadleaf weeds. Herbicide applications for perennial weed control can still be made effectively while the following conditions apply: Daytime temperatures are above 50°F, weeds have green leaves and can uptake herbicides, soils are not frozen. More info here: Broadleaf Weed Control, Nebraska Extension Turf iNfo.
Example On-Farm Research N Rate and Timing Protocols (These can be tailored a number of ways to fit various application timing, N source, and rates). The first protocol could just focus on 2 timings or 2 rates if a grower didn’t want 4 treatments. Links to full protocols below:
The York County Corn Grower plot and several on-farm research studies were harvested this past week. Thank you to Ron and Brad Makovicka for planting, harvesting, and hosting the corn grower plot and to all the seed companies who participated! The plot averaged 277 bu/ac on 190 lbs N of fall applied anhydrous and 3 gal of starter. That’s a great nitrogen efficiency per bushel produced! You can view the results at jenreesources.com or can pick up a hard copy of the results at the York Co. Extension Office.
I also wish to thank all of the cooperators who participate in Nebraska Extension’s On-Farm Research Network, especially all of you who work with me! The farmers conducting studies in this part of the State account for nearly 1/3 of the studies being conducted state-wide! A number of previous years’ results in addition to this year are studies involving nitrogen management. I will share more specific study results in the future. For now, with nitrogen prices continuing to climb, sharing ideas for consideration to try on your farms.
- Nitrogen Timing: Fall vs. Spring Anhydrous OR Combination of pre-plant nitrogen plus in-season nitrogen. We have one continuous fall vs. spring applied anhydrous study in York Co. and I’ve summarized results of several split applied studies in the past. It’d be great to have more producers trying these types of studies.
- Nitrogen Rate: 50 lbs N +/- grower rate. For example, consider: 100, 150, 200 lbs N/ac comparisons or 130, 180, 230 lbs N/ac comparisons. Growers doing these studies continue to find minimal yield gain for more N (less than 5 bu/ac for increasing 50 lbs N/ac). This year is a great one to try this for yourself with the high N prices.
- Nitrogen product substitute: There’s a number of products that are in some way promoted for reducing nitrogen, either by the product using microbes to help “fix N” for corn or using microbes to make N more available. So, consider trying a product like those and reduce the nitrogen by a set rate (30-50 lbs/ac) vs. a control with full N rate without the product. We do have a few studies in 2021 with these products and will share those results this winter.
- Reducing plant population under irrigated system using a strong flex hybrid. A handful of guys I know have tried this and have determined the population that gives them the best economic return for reduced nitrogen and water inputs. Some have also considered strong non-irrigated hybrids under pivots to reduce water and nitrogen inputs.
- Planting another crop: I have heard several saying they plan to plant more soybeans. A number of growers have also increased interest in milo (grain sorghum) due to the lower inputs necessary.
- For those who own land (perhaps easier with a pivot depending on where you are in the State) and have cattle, perhaps consider the economics of annual forages for your particular operation.
- Growing nitrogen via interseeding cover crops or planting corn into terminated vetch or solid stand of red (or white?) clover. I realize this one is more outside of the box and there’s a lot of questions surrounding it. The past few years, especially 2021, provided opportunity for numerous observations and learning experiences from growers trying these things. I just need time to summarize and will share this winter.
I know most producers are trying things on your own on your farms. The above are just some additional ideas for consideration and an opportunity to try via on-farm research to obtain more data. I will share specific protocols next week. The data helps inform all of us on practices/products that are research-proven in Nebraska.
Tar Spot of corn was found in York County via a sample submitted by Jon Propheter last week. Nothing to worry about this season. It can be easily confused with southern rust teliospores this time of year. Will share more on management this winter.
(Phtotos below: left-hand photo is tar spot, one lesion, very low incidence. Doesn’t scrape off leaf. Right-hand photo is southern rust teliospores; you can see the raised pustules looking closely in the photo and can rub them off.)
BugFest 2021 is now open at https://go.unl.edu/bugfest2021 till Oct. 24! There are videos about Nebraska Tiger Beetles, Wild Bees, Bed Bugs, Magical Creatures, How to Draw Insects, and much more.
Young, Beginning and Small Farmers Symposium November 8: Through a series of fast-paced panel discussions, participants will co-create innovative solutions regarding: Challenges facing young, beginning and small farming operations; Existing programs for financing young, beginning and small farmers; Innovative resource approaches for the farm of the future. This program will be held from 9 a.m.-4 p.m. (registration at 8:30 a.m.) at the Nebraska East Union on UNL East Campus in Lincoln. It will also be streamed live online. Those wishing to attend in person need to register and request a parking permit. There is no cost. Additional details at: https://go.unl.edu/hzcj.
Crop Update: The armyworm calls have greatly subsided other than “is it ok to plant wheat and/or rye now?” I was encouraging planting them last week. So, yes, would encourage planting now, and also am encouraging to scout (even though I appreciate that’s hard with harvest!). Hopefully they’re moving south, although it’s unfortunate from the tweets I’m seeing in Kansas now of damage there. I did get a call from the Spalding area where a newly seeded rye field was taken out and established alfalfa stand mowed to the ground, so there may still be some around.
For those cutting milo, heard a report of the cutter bar being full of what Dr. Bob Wright identified as a plant bug (Lygus sp.). They have piercing/sucking mouthparts and feed on flower buds and seeds on a range of plants. If you’re also noticing them, they should die in the grain bin and not be a problem. We just really need a freeze! A freeze would also help with those tiny, black biting insects called minute pirate bugs and with the flies!
Starting to receive questions on fall burndown herbicides and lots of questions regarding nitrogen with input prices. Will share more on this in upcoming weeks, but for now, I have a picture of the fall burndown herbicide table from the UNL Guide for Weed Management (page 93 & 139) on my blog site if that helps. Planting rye also reduces winter annual weeds and marestail.
SCN Sampling: As agronomists are taking soil samples for fertility, please ask them to split the sample and send in for soybean cyst nematode (SCN) as well. You can also target these samples (0-8”) from areas of the field that yielded less and from field boarders/entryways. I often just use plastic quart-sized ziplock bags and label them as “SCN”. We appreciate the support of the Nebraska Soybean Board and your soybean checkoff dollars used for free SCN testing, so be sure to test this year. The address to submit samples and more information on sampling for SCN can be found here: https://go.unl.edu/aui2.
Nightshade in cornfields: Taking corn notes this fall, have again seen lots of black nightshade in fields (also some horsenettle). Seems to me like it’s been on the increase the past few years in corn fields. In asking via Twitter if others also observe it more, it appears that people do from messages sent directly to me. I’ve been seeing it in both row directions in ridge-till fields and a few no-till ones. Grateful for Orvin Bontrager sharing his experience and observations! He shared, “Ridge till fields that had been hilled with east-west rows. Especially if get rain or watering before canopied. Have seen this for years. Not as much on rotated soybean fields more on long term continuous corn. Undisturbed residuals containing mesotrione seems to control.” Mesotrione is in products like Lexar, Lumax, Callisto, Acuron, Resicore, etc. So, for those asking how to control this, in no-till perhaps consider using a product containing mesotrione and for ridge-till, perhaps if you have a way to follow hilling with some mesotrione can help?
The bigger reason for my concern is if the corn residue will be grazed. Nightshade and horsenettle contain toxins in all plant parts with the concentration increasing in all the parts, except in the berries, as they mature. A frost won’t reduce the toxicity. I would hope the amount of corn residue would off-set any impacts from the nightshade/horsenettle plants.
Dr. Jerry Volesky, Extension forage specialist, shared the following, “It is very difficult to determine exactly how much black nightshade is risky. Guidelines say that a cow would need to consume 3 to 4 pounds of fresh black nightshade to be at risk of being poisoned. These guidelines, though, are considered conservative since there is little data on the actual toxicity of nightshade plants. Also encouraging is that reports of nightshade poisoning have been very scarce in the past. Fortunately, even though nightshade plants remain green fairly late into the fall, cattle usually don’t appear to seek out nightshade plants to graze. However, green plants of nightshade might become tempting toward the end of a field’s grazing period, when there is less grain, husks, or leaves to select. So common sense and good observation must be your guide. Scouting fields to estimate the general density of nightshade plants will help you determine any potential risk. Secondly, and particularly near the end of a field’s grazing period, closely observe what the cattle are eating to see if animals might be selecting nightshade plants.”
Crop Update: Grateful for the harvest that’s been achieved thus far! Bean harvest slowed with humidity increasing moisture (which could also be a blessing after dropping so low), and corn harvest increased. Some pivots are running for newly seeded cover crops and small grains since we missed the rains. Couple reminders: Armyworm FAQ at: https://go.unl.edu/skx2. Also, check fields for stalk rot. I use a pinch test taking my thumb and first finger to ‘pinch’ a lower internode on 20 plants in a row. Obtain a percentage of plants that easily ‘give’ to determine % stalk rot. Video: https://youtu.be/7z75VN1c51Q.
Soybean moisture was last week’s topic of discussion. The Center for Ag Profitability released an article on the economics of crop harvest moisture at: https://go.unl.edu/o7hx and also provides a moisture loss calculation tool. Growers were pretty frustrated with yield losses due to overly dry beans and how this happens rapidly after a few hot days each year. By the week’s end, with increased interest in storing soybeans, several growers had asked about the economics and legality of grain storage rewetting.
Regarding the legality, while it is illegal to add water to any grain crop, it is legal to run aeration fans when humidity levels are high to increase moisture levels of beans. Dr. Ken Hellavang is an engineer at North Dakota State University that UNL also utilizes for our grain storage questions. He cautions to be aware of adding too much moisture as damage to bins can occur. He provides specific instructions at this website. A portion of his comments are shared below. By taking into consideration what he shares, economics of soybean moisture, and cost of running the fans, growers can determine the economics for your specific situations.
“Hellevang recommends producers operate aeration fans during weather with an average relative humidity of about 70 percent if they want to recondition soybeans to 13 percent during normal fall temperatures of 30 to 60F. If a fan runs continuously, the beans will lose moisture during periods of low humidity and gain moisture in high humidity. Be aware that the air will be heated 3 to 5 degrees as it goes through the fan, which reduces the air relative humidity slightly.
A reconditioning zone develops and moves slowly through the bin in the direction of the airflow, which is similar to a drying zone in natural-air drying. Depending on geographic location, not enough hours of appropriate temperature and humidity air may be available to move the reconditioning zone through the entire bin during the fall.
Reconditioning occurs the fastest when the airflow rate, cubic feet of airflow per minute per bushel (cfm/bu), is high and the air is warm and humid. It will be the most successful in a drying bin with a fully perforated floor and a fan that can deliver at least 0.75 cfm/bu. Even with this airflow, moving a reconditioning front all the way through the bin probably would take at least a month of fan operation.
Producers need to compare the cost of fan operation with the benefit of marketing at the desired moisture content. To estimate the cost of operating the fan, assume a 1 horsepower fan motor will use 1 kilowatt of electricity for each hour of operation. For example, if reconditioning the soybeans takes 30 days of fan operation, that is 720 hours. Achieving an airflow rate of 0.75 cfm/bu on a 42-foot-diameter bin filled 20 feet deep with soybeans would require a 15 horsepower fan. The cost to operate the fan, assuming an electricity cost of 10 cents per kilowatt-hour, is $1,080.
Increasing the moisture content from 9 to 13 percent would increase the quantity of soybeans by 1,019 bushels. (Multiply by price per bushel to determine economics compared to cost of operating the fan). You would need only a 3 hp fan to provide an airflow rate of about 0.25 cfm/bu, but reconditioning the beans would take about 90 days.
If you ran the fan just in periods of very high humidity, such as during fog or when the relative humidity is near 100 percent, the soybeans in part of the bin would be too wet to be stored safely. Mixing the wet layers with dry layers would reduce the spoilage risk and discounts for marketing wet beans. However, stirring increases the bean damage. Emptying the bin and moving the beans through a grain-handling system will provide only limited mixing because the majority of the grain comes from the top of the bin in a funnel shape with a center unloading sump.
A humidistat can operate the fan when the relative humidity will average about 70 percent. Even though the humidity level varies considerably during the day, it will average about 70 percent if the fan is operated for a time when the humidity is 90 percent and for a time when it is 50 percent. Setting the humidistat to operate the fan when the humidity exceeds about 55 percent would be a reasonable starting point. However, the humidity setting would need to be adjusted based on a measured soybean moisture content. To avoid wetting the beans to moisture levels unsafe for storage, add a second humidistat to stop the fan when the relative humidity reaches very high levels or use a microprocessor-based fan controller that monitors temperature and humidity, and runs the fan only when air conditions will bring the crop to the desired moisture content. A disadvantage of these options is that the fan does not run as many hours.”
Harvest: Good to see harvest going and have heard some great bean yields! Also heard numerous reports of how hard it was to cut beans with green stems, bean stems falling over due to stem borer and winds, and beans running 9-11% moisture. There’s some chalky looking beans due to Diaporthe complex and purple seed stain was also observed in some varieties. Harvest safety is still the greatest priority. I don’t think I’ve heard of so many combine fires in one week as what we experienced last week in the U.S. and Canada, including several in Nebraska. Hopefully all the people were ok and the farmers can get going again somehow. Also, this past week was brutal driving with dust flying on gravel roads with sun glare at dusk. Lights on, stop at intersections and railroad crossings, please be safe!
Armyworms: Hopefully this is my last week talking about them! The questions have differed each week, so I share in hopes that it helps. We’ve just not seen these types of numbers for decades (from what I’m told). What has been interesting is hearing stories. One person who called me relayed a historical account of families and neighbors staying up all night driving up and down the roads squashing armyworms to keep them from crossing the roads into other fields. That’s dedication!
We put together a FAQ in CropWatch of common fall armyworm questions at: https://go.unl.edu/skx2. Last week the calls transitioned to pasture questions around products labeled for pastures with 0 day grazing restrictions with cattle present. Warrior II, Mustang Max, Beseige, Prevathon have 0 day grazing restrictions. You can see additional active ingredients, grazing, and haying restrictions at this website from Auburn Extension.
(Photo caption: armyworms in a pasture. You can typically find them in the edges between the brown/green. A lot of stress already in pastures due to drought. New growth observed shortly after insecticide application to kill the armyworms.)
Planting small grains and armyworms: I need to clarify from last week’s article that I didn’t mean to imply they needed to be seeded last week or immediately, just that they should still be seeded if that was in the plan. Ideally, yes, the sooner after harvest they’re seeded, the better establishment that typically occurs. But there are risks that one also needs to consider, such as the Hessian fly free date for wheat. For those who called, we discussed an option of a ‘wait and see’ approach where small grains for either grain or cover crop could still be planted in early October and still obtain good growth and establishment. Waiting after the Hessian fly free date (which occurs during various dates in late Sept. for Nebraska) and until the first full week of October may allow for enough cooler weather for the fall armyworms to head south and allow newly planted small grains to be established. We honestly don’t know when they will move south. Delaying till early October is one approach instead of trying to get small grains planted and being worried about scouting them for armyworms as they emerge while you’re also trying to harvest.
Cover Crop Seeding Rates for small grains (rye/wheat/triticale) is another question I’ve received. If seeding for erosion or even weed control, seeding rates of 20-35 lb/ac. are often fine. If you are receiving payment for EQIP or from another entity such as NRD or Pheasant’s Forever, they may specify the rate that needs to be seeded. For grazing, UNL typically says aim for a seeding rate of 60-70 lb/ac, but I’ve heard producers use anywhere from 40-80 lb/ac. Two publications with considerations for planting cover crops after corn or soybean can be found here: https://mccc.msu.edu/statesprovince/nebraska/.
Nebraska Extension Dean Interviews: If you’re interested, you can find information about the candidates here: https://ianr.unl.edu/dean-and-director-nebraska-extension. The public is invited to a meet and greet for the NE Extension Dean candidates on October 1, 6, and 8 from 5:30-7:30 p.m. at Raising Nebraska (state fairgrounds) in Grand Island. There is also a zoom link for these. If you’re interested in attending via zoom, please let me know and I’ll send you the links. At a time when Extension systems have been cut across the country and with systems in other states moving to regional instead of county-based models, it’s a critical time in Nebraska Extension’s history for the future of what Extension in Nebraska looks like. Would encourage you to attend and ask questions if you’re interested.
There’s times after I write this column on Sunday nights that I could turn around and write another one after Monday hits! Last week was one of those weeks, so here’s considerations for this week. Also, reminder to remove ET gages and irrigation scheduling equipment from fields before harvest.
Woolly Bear Caterpillars have been around since fair time at lower levels in landscapes and fields. However, they are showing up fairly heavy in later season soybeans right now, so it’s wise to be scouting for them. They’re doing a lot of leaf defoliation, yet also watch the pods for clipping or feeding on them. The economic threshold for defoliation is 20% in reproductive stages. I have been seeing them dying in fields from beneficial fungi as well, so look for dead/dying caterpillars and consider this as well. Decisions to treat are very field dependent. Organic options include various Bt products which impact caterpillars but don’t hurt other beneficial insects. Be aware of pre-harvest intervals (PHI) listed on the label (also pages 338-344 of 2021 Weed/Disease/Insect Guide); most products list 18+ days.
(Photo captions below): 3 woolly bears on this plant (left), lots of defoliation (top, right), and what dead woolly bears due to beneficial fungal pathogens look like (notice the duller color-they start almost looking a gray/white with age and don’t move).
Fall Armyworms: My phone went crazy again last week about them. Feel badly for all who had to reseed new alfalfa seedings, reseed cover crops, reseed small grains, and for all reseeding lawns. Their feeding happens so quickly. Even those who cut older stands of alfalfa were finding the armyworms weren’t killed after cutting. I was most commonly asked if cover crops or small grains should even be planted/replanted until the fall armyworms disappeared. Yes, they should as these small grains and covers obtain better establishment and growth the sooner they’re planted. The fall armyworms will eventually move south; however, entomologists don’t know the exact trigger for that. With the moths still flying, we may continue seeing larval feeding for a few weeks. What I told people who called or texted was to plant (being prepared with a product in mind should you need it), scout once the new seedlings start coming and be ready to apply a product if necessary. I listed a number of products in last week’s column, including organic options for consideration. Not every field nor lawn is impacted; it’s all dependent upon where the moths lay their eggs. A field or lawn that was impacted once may not be impacted again.
Harvest: Beans have dried down fast in spite of some green stems and leaves attached. Hearing moistures ranging from 10-14% on 2.0-2.5 maturity beans with yields depending on rain and disease. Even the corn is drier than what it appears inside some of these fields as I’m taking on-farm research notes. With harvest most likely ramping up this week, please be safe! It’s really dry which makes for dangerous road conditions and greater fire potential.
Harvesting soybeans as close to 13% is a goal for which to aim, in spite of the challenge. It’s perhaps a combination of art and luck depending on environmental conditions. Consider beginning harvest at 14% moisture making combine adjustments and operating at slower speeds as necessary. While there’s a dock of around 2.5% for the first 2 points delivering wet beans, delivering soybeans much below 13% moisture reduces profits because there’s fewer bushels to sell (load weight divided by 60 lbs/bu assuming 13% moisture). Selling soybeans at 8% moisture, you’re losing about 5.43% yield; at 9% moisture, it’s 4.4%; at 10% moisture, 3.3%; at 11% moisture, 2.25%; and at 12% moisture, it’s 1.14% yield loss. That doesn’t take into account additional risk for shatter losses during harvest. Only 4-5 beans on the ground can add up to a bushel/acre loss due to shatter. The following are profit examples:
Example 1. If the grower was to sell beans at 13.8% moisture, he/she would be docked 2.5% of the selling price of $12.30/bu, reducing the actual price to $11.99 per bushel. Total income per acre would be: 75 bu/ac yield x $11.99/bu = $899.25 per acre gross
Example 2. If the soybeans were harvested at 9% moisture, there would be 3.3 fewer bushels per acre to sell (4.4% of 75 bu/ac yield due to water loss): 75 bu/ac – 3.3 bu/ac =71.7 bu/ac yield x $12.30 = $881.91 per acre gross. In this example it’s better to take a dockage for selling beans at 13.8% moisture than sell them at 9%. The difference is a positive gain of $17.34 per acre or around $2341 on a 135 acre field.
Example 3. If the soybeans were harvested at 12% moisture, there would be 0.86 fewer bushels per acre to sell (1.14% of 75 bu/ac due to water loss): 75 bu/ac – 0.86 = 74.14 bu/ac yield X $12.30 = $911.92 per acre gross. If you can’t hit 13%, it’s still pretty profitable to sell them for 12% moisture compared to the other examples. Here’s wishing you a safe and profitable harvest!
Fall Armyworms: Received numerous reports of fall armyworm damage this past week from Kansas-Nebraska state line north to York. Damage was occurring in new alfalfa seedings in addition to established alfalfa, a new triticale seeding, and several lawns. With moths still being observed, we may see fall armyworms around for a few weeks yet, so it would be wise to be watching any alfalfa, wheat, rye, triticale and lawns for them. There’s no good way of knowing where they’ll appear; it’s all based on where the moth chooses to lay her eggs. Several reports of one field affected while the field next to it is fine. Same with lawns. Egg masses are fuzzy white masses that can include up to 200 caterpillars and the eggs can hatch in 2-5 days. Newly hatched larvae will be thin and often black/gray in color. I have some pictures from my colleague Jody Green at jenreesources.com.
In town, if you find the egg masses on lawn furniture, siding, or garden features, simply wipe them up with paper towel and discard in the garbage. They’re far easier to control when the larvae are ¾ inch or less. When they get larger than this, insecticides aren’t as effective, and usually, by that time, so much damage has occurred that the area will need reseeded. Products with active ingredients such as bifenthrin or permethrin are effective and are options for both farmers for fields and also homeowners with lawns. Sevin is also an option for both. Kentucky bluegrass lawns may be able to recover from rhizomes regrowing in the spring. However, fescue and ryegrass will need intervention this fall for reseeding. An organic insecticide option is Dipel which will take a little longer to work, but is still effective on smaller larvae. For lawn situations, it’s important to water the insecticide product in the ground to get the granules off the leaf blades and into the soil.
(Photo caption: Fall armyworm moth, egg mass, and larvae. Photos via Jody Green and UNL Entomology).
Large grubs on concrete: Had several reports last week of large white grubs on concrete stairs, sidewalks, and driveways. They are really large, up to 1.5 inches. What’s interesting about them is they crawl on their backs! These are grub larvae of the green June beetle which is a large beetle that often sounds like it’s ‘buzzing’ during June and July. The adult beetle can cause damage to ripening fruits such as stone fruits and berries. However, the grub larvae are not a major turf pest, unlike other grub species. They feed on thatch layers and organic matter, but don’t really attack lawn roots. They make holes in the soil, so rain and irrigation will drive them out onto concrete.
Small Grains and Weed Control: Last week I mentioned considerations for wheat planting. Even if small grains aren’t taken for seed, they do a tremendous job for weed and erosion control, provide an option for grazing, and uptake excess moisture and nutrients (helpful in seed corn field situations). Small grains, particularly oats and rye, have been proven to help with reducing soybean pathogens such as fungi and nematodes causing SDS and SCN. I’ve been watching a couple side-by-side soybean fields in which one was planted green into rye and the other didn’t have rye. Even the farmer commented on it to me this week how the quarter without rye has senesced earlier and has problems with anthracnose and Diaporthe complex (including pod and stem blight) while the other is essentially disease free.
Wheat provides an option for both grazing and grain. Rye provides the best option for earliest green-up/growth in the spring and longest seeding time as it can be seeded into December. Triticale provides the most biomass, including for haying and small grain silage, but produces the latest into late May/early June. It’s too late to plant oats for the fall, but they are an option for the spring. All keep the ground covered from light interception penetrating the soil surface which allows weed seeds to germinate.
Researchers from K-State looked at marestail (horseweed) and palmer amaranth control from 2014-2015 in no-till soybeans at six locations in eastern Kansas. They also found the majority of marestail emerged in the fall (research from UNL showed up to 95% does). They compared five cover crop treatments including: no cover; fall-sown winter wheat; spring-sown oat; pea; and mixture of oat and pea. Cover crops were terminated in May with glyphosate and 2,4-D alone compared to a control of no herbicide use. Ten weeks post-termination, palmer amaranth biomass was 98% less in winter wheat and 91% less in spring oat compared to no cover crop and no herbicide control. The same cover crops were also compared to a no cover crop treatment where all received a May herbicide application of 2,4-D and glyphosate with residual herbicides of flumioxazin + pyroxasulfone (Fierce). With the addition of residual, there was no difference in palmer amaranth biomass in the no cover crop with residual herbicide and all the cover crop species where a residual herbicide was added. I share the Research Figure on my blog site which is incredibly visual and have shared it in pesticide trainings as well. To me, it so visually shares how well residual herbicides can work, which we’re aware of. However, what strikes me the most is how much work that residual had to do on its own to achieve the same control as a cover crop + residual herbicide. Adding the cover crop reduced the load of the herbicide alone and is another tool in the toolbox. It also shows how effective cover crops for weed control can be for organic systems if there’s a solid way for terminating them. I realize cover crops don’t fit every field or every situation. Just some considerations as we especially think of situations where planting a small grain this fall could be used for weed and erosion control and/or grazing.
Crop Update: The cooler weather and rains have been welcome here even though other parts of the State have had excess and flooding. I think grain fill has slowed down some in the corn, which will hopefully help. The rains will help the beans, milo, and pastures. If we can escape storms, early planted beans look pretty powerful this year! In a recent conversation with Dr. Jim Specht, he was sharing how he was anticipating really high bean yields. Upon asking him about that and also about the smoke/haze, he shared that he didn’t think it would have much impact on soybeans compared to corn. This is because soybeans are C3 crops where the photosystem saturates out at lower solar radiation levels; C4 crops like corn don’t, thus cloudy/hazy days have more impact on corn. The high humidity we’ve experienced has reduced transpiration of crops, allowing many non-irrigated soybeans to hang on till these August rains. As I’ve looked at crops in several counties, for the most part, it’s taken awhile for beans to start turning, even in the non-irrigated corners compared to what we typically see in dry years. Here’s hoping for some nice bean yields!
York Co. Corn Grower Plot Tour will be held this Thursday, September 9th from 5:30-7:00 p.m. at 1416 Road I, York, NE. Pizza and beverages will be provided. Attendees can guess the highest yield without going over for a chance to win a $50 gas card. We’re grateful to Ron and Brad Makovicka for hosting the plot and to all the companies represented in providing entries! We hope to see you there!
Wheat: I realize planting wheat is most likely not on many people’s radar in this part of the State. Yet, after attending the wheat and alfalfa expo today, just wanted to share a few thoughts and resources for those considering it. For those seeking resources, my colleague Nathan Mueller in Saline County has dedicated a section of his web page (http://croptechcafe.org/winterwheat/) to growing wheat in Eastern NE including an email listserv that shares new information. The website has a virtual variety tour where you can view varieties and their characteristics. A new tool on the website I learned about is a seeding rate calculator that helps in ensuring correct seeding rate based on the seed weight of the lot you receive. CropWatch also has its yearly ‘wheat edition’ in September, so be on the lookout for that this month at https://cropwatch.unl.edu and you can also check out https://cropwatch.unl.edu/wheat. Key points I emphasize for wheat include: killing out volunteer wheat in a mile radius at least 2 weeks prior to planting new wheat, treating wheat with fungicide seed treatment, and ensuring proper seeding depth by ensuring enough weight on the seeder particularly when no-till planting into residue.
I realize the economics for one year don’t look great for wheat. However, looking at the bigger picture, what is the value of that wheat crop in allowing additional time for a forage or cover crop, breaking pest cycles, and giving you an additional 2-3 months-time before needing to apply herbicides for weeds like palmer amaranth? What value does the residue provide for the following year to help reduce the number of weeds and/or in conserving soil moisture for the successive corn crop?
There’s also different ways of adding wheat into an operation. There’s some who have tried double cropping with both short season corn or soybeans after harvesting wheat. There’s also been interest regarding relay-cropping wheat and soybeans on Twitter. This past year, I had the opportunity to watch a few growers in the Archer/Chapman area try relay cropping wheat with soybeans on acres that were in seed corn the previous year. Their goals included using the small grain in wheat to aid in reducing palmer amaranth pressure and to obtain greater economic benefit from harvesting both a wheat and soybean crop. The Panhandle Research and Extension Center in Scottsbluff was doing the same with wheat and dry beans. There’s a lot we’re all learning in this arena and it’s just another way, with a lot more management challenges, to consider adding wheat in a crop rotation. Perhaps the biggest thing we learned was to have a high wheat seeding rate and proper fertility to allow the heads to be more uniform with less tillers that are short (similar to if one is raising a small grain for seed).
For those not desirous of planting wheat for grain, it can be used as a small grain cover crop for weed control as well. At two field days near Clay Center this summer, some individuals from Kansas and southern portions of Nebraska talked about how they recommend wheat or barley before a corn crop and rye before a soybean crop when considering a small grain cover crop for weed control. Their reasoning made a lot of sense. Wheat and barley don’t take off growing/greening up as fast as rye does. They also don’t obtain as much biomass (which also allows for faster nutrient cycling). They found farmers felt more comfortable planting corn green into wheat compared to rye for those reasons. I have no research or experience on that, but it makes sense and wanted to share if it’s something any of you would be interested in trying next year. In a soybean situation, I still recommend rye before the soybeans for weed control because of the increased biomass, and we’ll have data from Dr. Amit Jhala and his team this winter on that.