Reducing Soybean Seeding Rates: Can I reduce soybean seeding rates and still maintain yield? It’s a common question from soybean growers, especially those seeking to reduce input costs. Every year during winter meetings I share what our growers have found. We now have 11 years of On-Farm Research proven data.
The findings? Reducing soybean seeding rates from 180,000 or 150,000 seeds/acre to 120,000 seeds/acre doesn’t statistically reduce yields in 30- or 15-inch rows in silty clay loam and silt loam soils in south-central and eastern Nebraska. Results of 18 studies showed for seeding rates of 180K, 150K, and 120K seeds per acre, average yields were 69.0, 68.7, and 68.4 bu/ac, respectively (Figure 1). The early studies within this dataset all had seed germination of at least 90% listed on the seed bag. In all but two situations (seeded at 180,000 and achieving 88% germination), the growers were able to achieve 90% or greater of their planted stand.
As I share this data, I’ve often heard “but I seed higher rates because of X, Y, or Z…”; however, this dataset includes a lot of those reasons without negative yield consequences! I’ve worked closely with these studies in walking the fields; taking notes and pics; counting plants, pods, and seeds; so I’m really confident of the research and the fact that soybeans truly compensate for reduced populations! Outside of this research, I’ve also observed this in many soybean hail, crusting, and PPO inhibitor seedling damage situations. This dataset includes:
- The latest soybean varieties as the research was conducted from 2006-2017.
- Erect and bushy type varieties in growth architecture.
- Higher and lower yielding situations.
- Fourteen irrigated fields and four non-irrigated.
- Hail events occurring from cotyledon stage to R2 in some of these fields.
- Crusting in some non-irrigated fields.
- Seed treated in some fields and others without (determined by grower’s planting date).
- In some years, pod and seed count data were also collected; the data showed similar numbers of seeds/acre and ultimately yield per acre.
- Observations of increased plant branching at lower seeding rates and difficulty in telling the seeding rate treatments apart as the season progressed.
Our research data for 11 years shows no statistical yield differences in seeding rates from 120,000-180,000 seeds/acre in 15- or 30-inch rows in silty clay loam or clay loam soils. Thus, reducing seeding rates is a way to consider reducing input costs for 2018 without impacting your yield. If you dropped your seeding rate from 150,000 seeds/acre to 120,000 seeds/acre, you could save $10.08/acre, assuming a yield loss of 1 bu/ac, a seed cost of $60 per 140,000 seeds, and a savings of $25.71/ac on seed.
- Thus, if you plant between 140,000-160,000 seeds/acre, consider dropping your seeding rate to 120,000 and aiming for a final plant stand of 100,000 plants/ac based on our research findings.
- If you plant at 180,000 or more seeds/acre, consider dropping your seeding rate to 140,000 seeds/acre as a step-wise increment.
Still hesitant? Consider trying this yourself for your location! Consider using either this Two Population Treatment Design or Four Population Treatment Design. You also can download the Nebraska On-farm Research app, available in Apple and Android, to help you set up your plot design to obtain scientific results. If you have questions or need help setting up your research project, please contact me or anyone involved with our Nebraska On-Farm Research Network. To view all the graphs and additional data regarding 15″ row spacing with reduced seeding rates, please check out this week’s UNL CropWatch at http://cropwatch.unl.edu.
Beginning Soil Moisture: On Good Friday, I installed soil moisture sensors down to 4′ in non-irrigated no-till fields at Bladen and Lawrence. Last week I added three more sites at Clay Center, Superior and Byron. Thus far, the 3′ and 4′ are dry in all those locations other than Clay Center (only dry at 4′). At Superior, I could only get the soil probe in the ground 6″ into actively growing rye and 1′ in cover that winter-killed. I was just curious what kind of moisture existed currently in the southern tier of counties. I realize planting plans are in place and that we often receive rains in April/May. Hopefully it provides information that can be helpful in how to use that soil moisture. If we don’t get necessary rains, you may consider switching to a different crop, growing feed if you have cattle, or not terminating actively growing rye as originally planned but perhaps using it for feed. Will share graphs next week and I appreciate the growers allowing me to install these in their fields!
My top question the past two weeks has been about dicamba training. I just received the information regarding this training from our pesticide program coordinators.
First, to clarify some mis-understandings: Dicamba training is required for those applying the following dicamba products: XtendiMax®, FeXapan™, and Engenia®. These products are all Restricted Use Pesticides (RUP) this year; thus, you have to be a certified applicator to purchase and use these products. Dicamba training is not required if you’re applying dicamba corn products (unless it is the above-mentioned products).
Second, pesticide training of any kind is not the same as dicamba training. Dicamba training is completely separate. Having your pesticide applicator license does not qualify you to apply RUP dicamba in 2018.
Third, some have asked if everyone in the operation needs this training or not…specifically the person who is purchasing the RUP dicamba with his/her applicator license but is not the one intending on applying the chemical. NDA says that, “Dicamba-specific training is only required for application of the product, not for purchase of the product.”
- You need to be a certified pesticide applicator to purchase the RUP dicamba products.
- You need to be a certified pesticide applicator and complete dicamba training to apply the RUP dicamba product. So hopefully that helps clarify who in your operations need this training.
Your options for RUP dicamba training include the following:
- Nebraska Extension online training course hosted by eXtension. See the link at : https://campus.extension.org/login/index.php (1.25-1.5 hours).
- Crop Production Clinics or Nebraska Crop Management Conference. Details at https://agronomy.unl.edu/cpc and https://agronomy.unl.edu/ncmc
- County-hosted training sessions at the option of local educators presenting the video which is the same as the online training (1.25-1.5 hours).
- RUP dicamba product (XtendiMax®, FeXapan™, and Engenia®) manufacturer sponsored training. Each manufacturer will advertise individually.
I took the online training so I could better answer your questions. The link to the UNL online dicamba training can be found at the http://pested.unl.edu site or you can go directly to the training at: https://campus.extension.org/login/index.php. Once at this site, you will need to create an account. You will then be sent a confirmation email and upon opening that, you will be logged in. From the course list choose “pest management”.
Then scroll and click on “Online Training for Dicamba Herbicide”.
You will then need to register for the training. It will ask you to add your Nebraska pesticide applicator number in a specific field as well. Your name and applicator number are required before you begin the training. You can then click on the first video followed by the first quiz. It keeps track if you completed the entire video or not before you can advance.
I felt the information was good overall and I appreciated the fact that they mentioned how corn dicamba applications also influenced the problems we saw in 2017. They also share quite a bit of research regarding volatility, conditions/timing of temperature inversions, dosage amounts and effects on yield. The quizzes are short and were fairly common sense. You can click to check each answer once you have selected your choice and will have to submit all your answers before moving on. When you have completed all the videos and quizzes, you can have a certificate emailed to you. You will also be officially entered into Nebraska Department of Ag’s database. NDA said they will only honor those names in their database as those who’ve completed dicamba training.
NDA is asking ag retailers selling these RUP dicamba products to check the NDA database to ensure the person applying the product has received dicamba training. NDA’s dicamba information including record keeping forms, etc. can be found at: http://www.nda.nebraska.gov/pesticide/dicamba.html.
The other thing you need to know: some have asked if a group of people can watch the online training at the same time at your farmstead. The answer is actually no from the standpoint you all would have to watch the training on separate computers/devices. The only way your name is recorded in the NDA database is through your registration name and pesticide applicator number on the training site. It only allows one person to enter his/her information to view the training and complete the quizzes. If you attend an NDA approved face-to-face training such as at Crop Production Clinics, you can train as a group but will still need to supply your individual names and pesticide applicator numbers at the training.
Hopefully this helps clarify some of the questions you have and during this cold weather, you have the opportunity to get this training completed if you need it for 2018.
Reminder: York Ag Expo at the Holthus Convention Center in York January 10-11. Schedule of Events and Exhibitors: http://yorkchamber.org/yorkagexpo/
Educational Sessions: https://jenreesources.com/2017/12/26/york-ag-expo-educational-sessions/
May 23: Corn is looking good for the most part with few major concerns yet. Some have commented on the yellow-looking corn. This is most likely due to cool, wet soils rather than any nutrient issues. There may be field-specific issues such as saturated soils, compaction, and some herbicides that can cause this yellowing too. Also had a call on cutworms in seed corn but not widespread calls on this yet. Extension Educators have set up light traps for tracking cutworm moths and you can find that information here: http://go.unl.edu/rhhe. Cutworms will cause the most damage the first 7 days after corn emergence so scouting is important. The York County Corn Grower Plot was planted on April 24th with the corn currently at 2 leaf stage. Special thanks to Ron, Ray, and Brad Makovicka for hosting and the work put into this plot each year!
May 1: It never ceases to amaze me how quickly planting occurs each year! Corn planted the week of April 10th has emerged and for those fields that received hail from last week’s storms, I’m hoping we don’t see disease issues later on. Also of note, some have asked me about the CropWatch soil temperatures as they are higher than what some of you have been measuring in your fields before planting. The CropWatch soil temps at http://cropwatch.unl.edu/cropwatchsoiltemperature are averages of 24 hours under bare soil which may be different than the residue conditions in your fields and is an average of the entire day vs. one point in time. This may help explain some of the differences.
Many stands of alfalfa are lush green with over a foot of growth at this point. I looked at some alfalfa in Clay County that got dinged by cold temperatures in areas of the field and stopped growing. At this time I’m also finding quite a few aphids and a few alfalfa weevils. A disease common this time of year called spring black stem can be observed in nearly all alfalfa fields right now in the lower canopies. This disease consists of small black lesions on the leaves which eventually cause the leaves to turn yellow and drop. Normally this disappears with later cuttings as humidity and rainfall are typically high during the first cutting and can be managed with cutting the alfalfa. One option to consider according to Dr. Bruce Anderson, our Extension Forage Specialist, is to consider cutting alfalfa before bloom. He shares that weather can cause long delays and alfalfa doesn’t bloom very aggressively during spring. Bruce felt there were advantages to cutting alfalfa when it is 15-20” tall before bloom during first cutting including: weather compared to later spring, spread out alfalfa harvest if you consider cutting one field earlier, reduction in insect and disease problems by early harvest, and high feed value. It also potentially allows the second cutting to be ready before the summer heat which can lower forage quality. Disadvantages include lower yield from cutting early which could be made up in later harvest, regrowth may be slower if cut early, and the need to allow for longer recovery after first or second cutting to maintain long-term stands. So, harvesting before bloom may be something you wish to test in one of your fields this year and consider how this works for you, especially if you did have some frost damage or are having insect/disease issues in your alfalfa right now.
The field assessment workshops in Nebraska are hands-on and will show growers how to document eight sustainability and efficiency indicators via use of a laptop computer. The indicators are:
- land use,
- soil carbon,
- irrigation water use,
- water quality,
- energy use,
- greenhouse gas emissions, and
- water quality.
Please contact the Extension Educator listed for each site to preregister by Dec. 3.
Monday, December 7, 9 a.m. – 1 p.m.
UNL Extension Office in Lancaster County, 444 Cherrycreek Road
Contact: Tyler Williams, (402) 441-7180 or firstname.lastname@example.org
Monday, December 7, 5:30 – 9 p.m.
UNL Extension Office in Gage County, 1115 West Scott St.
Contact: Paul Hay, (402) 223-1384 or email@example.com
Tuesday, December 8, 9 a.m. – 1 p.m. Nemaha County Hospital Meeting Room, 2022 13th St.
Contact: Gary Lesoing, (402) 274-4755 or firstname.lastname@example.org
Tuesday, Dec. 8, 5:30 – 9 p.m. UNL Extension Office in Fillmore County, 1340 G St.
Contact: Brandy VanDeWalle, (402) 759-3712 or email@example.com
Wednesday, Dec. 9, 9 a.m. – 1 p.m.
UNL Extension Office in Clay County, 111 West Fairfield Contact: Jennifer Rees, (402) 762-3644 or firstname.lastname@example.org
Wednesday, Dec. 9, 5:30 – 9 p.m.
UNL Extension Office in Merrick County, 1510 18th St.
Contact: Troy Ingram, (308) 946-3843 or email@example.com
Thursday, Dec. 10, 9 a.m. – 1 p.m. UNL Extension Office in Dodge County, 1206 West 23rd St.
Contact: Nathan Mueller, (402) 727-2775 or firstname.lastname@example.org
Friday, Dec. 11, 9 a.m. – 1 p.m.
UNL Extension Office in Saunders County, 1071 County Road G
Contact: Keith Glewen, (402) 624-8030 or email@example.com