The Soybean Flowering – Summer Solstice Fallacy

Shawn P. Conley, Lindsay Chamberlain and James Specht

Every agronomist has been ingrained with the Nowledge that soybean is considered a “short-day” plant and will not flower until after June 21st a.k.a. the summer solstice. This belief has held true for decades; however, with agronomists now preaching the virtues of early soybean planting, coupled with the power of Twitter, we now see pictures and evidence of soybean flowers occurring as early as June 1. This empirical evidence has prompted many to question the foundational belief.

In soybean, floral induction occurs when soybean leaves can measure the night length (from dusk to dawn), and thus begins when unifoliolate leaflets appear at stem node 1 (V0) and a young trifoliolate leaf appears at node 2, with induction continuing thereafter in every subsequent leaf (Wilkerson et al. 1989; Fehr and Caviness, 1977). If soybean is planted early enough, flower initiation can then be triggered on the front of the summer solstice (Figure 1). This response is dependent upon the maturity genes present in the adapted cultivars and region of country, however given the germplasm available to farmers in the north central region it is plausible that any soybean planted in this region would flower “early” if planted early.

In 2018 we have experienced exceptionally warm temperatures after V1 that have significantly hastened the calendar date of R1, because the temperature sensitivity of floral evocation (development of floral meristems into flowers – the first such visible flower leading to an R1 stage call), though floral induction in itself is not very temperature sensitive.  In NE in 2017, the website program SoyWater (SoySim) predicted that an Apr 24 planting date would lead to the R1 stage dates for MGs 1, 2, 3, & 4 to occur on Jun 12, 14, 17, & 19; however, this year (2018), SoyWater (SoySim) is predicting for the same planting date of Apr 24 and near similar MGs, R1 stage dates of June 05, 10, 13, & 16!  Those R1 stage predictions were (as Dr. Specht recall) 3-5 days later a couple of weeks ago, so not only a warm spring, but also this exceptional heat wave in the last few days has hastened floral evocation.  R1 is likely to be earlier in all NC USA areas that have experienced both early soybean planting and a much warmer than normal spring. Early soybean flowering has many management implications including shorter herbicide label timings for dicamba (up to R2) and glyphosate products (through R2) (FYI it usually only takes 3-5 days to go from R1 to R2) and earlier risk for white mold infection. In 2018 it is paramount that you scout and don’t just rely on the calendar for spray applications!

Figure 1. Planting date by day length hours in Lincoln NE.

Literature cited:

Fehr, W.R., Caviness, C.E., 1977. Stages of soybean development. Cooperative Extension Service, Agriculture and Home Economics Experiment Station, Iowa State University, Ames, Iowa.

G, G. Wilkerson,* J. W. Jones, K. J. Boote, and G. S. Buol. 1989. Photoperiodically Sensitive Interval in Time to Flower of Soybean. Crop Sci. 29:721-726.

Variable Germination and Emergence in Soybean: Which Seeds Are Still Viable?

Many of us, including myself, have planted under less than ideal soil conditions this spring.  Often the ground was worked a little on the wet side leading to clods and variable seeding depths for our soybean crop.  Reports of variable and delayed emergence in conventional (more common) and no-till soybean is raising replant and seed viability questions in several areas across the Midwest.  If soybean was planted into dry soil and had not imbibed water (seed did not swell) then there is little to no concern for growers.  Once a significant rainfall event occurs, the soybean will imbibe water, germinate, and should emerge normally.  For yield estimates, we would assign the day it rained as the new planting date.

The more difficult question to answer is “How viable is the soybean seed once imbibition and/or germination has begun?”  The critical seed moisture content for soybean germination is 20%.  A soybean seed that has imbibed water, has a split seed coat, or has an emerged radicle will continue to germinate and grow as normal once the seed is re-hydrated if the seed (embryo) remains above 20% moisture (Senaratna and McKersie, 1983) (Image 1).

Image 1. Soybean germination

If the moisture content within a soybean seed falls to 10% due to dry conditions after germination has started, then a dramatic difference exists among the different seed germination stages.  If the seed has imbibed water for 6 hours (seed is swollen, but the seed coat has not broken), then the seed is dehydrated to 10% moisture, germination is not affected.  If the seed has imbibed water for 12 to 24 hours (seed coat broken, but prior to radicle emergence), then germination is reduced to 60 to 65%.  If the radicle has emerged and seed moisture levels drop to 10%, then no survivors can be expected (Image 2).

Image 2. Variation in soybean imbibition

To test seed viability, growers can conduct a simple germination test.  First excavate 100 soybean seeds and wrap them in a damp paper towel.  Place these seeds in a warm location, and after 24 to 36 hours, count the number of seeds that have germinated (Image 2).  Remember that a typical soybean germination is 90% (Image 3).

Image 3. Soybean germination roll test

Literature Cited:

Senaratna, T. and B. D. McKersie.  1983.  Dehydration Injury in Germinating Soybean (Glycine max L. Merr.) Seeds.  Plant Physiology 72: 620-624.

The WSMB Free Soybean Cyst Nematode Testing Program is Back in 2018!

Ann MacGuidwin, Damon Smith and Shawn P. Conley
The WI Soybean Marketing Board (WSMB) sponsors free nematode testing to help producers stay ahead of the most important nematode pest of soybean, the soybean cyst nematode (SCN). Eggs of SCN persist in the soil between soybean crops so a sample can be submitted any time that is convenient. The soil test report indicates the number of eggs in the sample and is useful for selecting the right variety for the next soybean crop. Retests of fields planted with SCN-resistant varieties over multiple years shows how the nematode population is responding to variety resistance and provides an early warning should the nematode population adapt to host genetics.
In the spring of 2012, the WSMB expanded the nematode testing program to include other pest nematodes in addition to SCN. These nematodes are less damaging to soybean than SCN but can cause enough yield loss to warrant treatment. As is the case for SCN, there are no rescue treatments for nematodes so the primary purpose of this year’s soil test is to plan for next year’s crop. Soil samples collected in corn for nematode analysis have predictive value for explaining yield if they are collected before the corn V6 growth stage. Sampling early in the season will provide information about the risk potential for the current corn crop AND the next soybean crop.
The assays used to recover nematode pests other than SCN in soil require that the nematodes are alive. So, it is important to keep the samples moist and at least room temperature cool. Collecting a sample that includes multiple cores ensures that there will be plenty of root pieces to assay. It is not necessary to include live plants in the sample. The soil test report will indicate which pest nematodes are present and at what quantities and their damage potential to soybean and corn based on the numbers recovered.
For more information on SCN testing and management practices or to request a free soil sample test kits please contact: Jillene Fisch at (freescntest@mailplus.wisc.edu) or at 608-262-1390.
Click to view more information on our WI SCN testing program or visit The SCN Coalition.
Remember the first step in fixing a nematode problem is to know if you have one! The WSMB sponsored nematode testing program provides you that opportunity. So Wisconsin farmers….”What’s you number?”

Wisconsin Industrial Hemp Production: A basic FAQ guide for growing an old crop in a new era

Authors: Shawn P. Conley, John Gaska, Adam Roth, Cheryl Skjolaas, Erin Silva, Loretta Ortiz-Ribbing, William Barker, and Patrick Robinson

INTRODUCTION
Wisconsin growers will be able to grow and process industrial hemp under 2017 Wisconsin Act 100, a law recently passed by the Legislature and signed by the Governor. The law directs the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) to write an emergency administrative rule that will spell out the details of the program, including requirements for growers.

This document will be updated as new information becomes available. The emergency rule will remain in effect until July 2020 or until a permanent administrative rule is approved. Please consult the official DATCP and State of Wisconsin websites for official information.

Questions that likely will be addressed by the emergency rule are noted here.

PLEASE NOTE:
Only official rules, regulations, and notices as posted by the DATCP and State of Wisconsin can be used. Official information from the DATCP and the State of Wisconsin supersedes any information contained here.

References for official state information:
https://datcp.wi.gov/Pages/Programs_Services/IndustrialHemp.aspx
https://datcp.wi.gov/Documents/IHLegCouncilMemo.pdf
http://docs.legis.wisconsin.gov/2017/related/acts/100/_4

If you are interested in receiving email updates from DATCP, please subscribe here!

Please click for more information on the Industrial Hemp Research Pilot Program

It is unclear whether there will be a legal mechanism to get hemp seed into Wisconsin in time to plant the 2018 growing season. The Drug Enforcement Administration (DEA) will likely require a DEA Import license for any seed coming from outside Wisconsin. Anyone planting before a license is issued is most likely taking a significant risk.

What is industrial hemp?
As defined in s.94.55 (1) Wis. Stats. “industrial hemp” means the plant Cannabis sativa L., or any part of the plant including seeds, having a Delta-9-Tetrahydrocannabinol (THC) concentration of 0.3% or less, although this allowable percentage may be raised up to a maximum concentration of 1% THC if in the future federal law allows a higher percentage. The statute includes the definition a substance, material, or product that is not designated as a controlled substance under the state Uniform Controlled Substances Act, or the federal Controlled Substances Act, or both.

Industrial hemp is classified as non-drug Cannabis sativa varieties, whose fruit is technically an achene, or a single-seeded fruit similar to a sunflower. Both the seed and hemp’s tall stalk provide significant carbohydrate feedstocks for a wide variety of industrial purposes that are used in several countries. The oil pressed from hempseed in particular, is a rich source of polyunsaturated omega-3 and omega-6 fatty acids, which are essential for human health. These same fatty acids in hempseed oil make it a fine drying oil that is used in the production of paints, varnishes, and other coating materials. Plastic flooring such as linoleum and similar materials have been made from hempseed oil, and other non-food uses of hempseed oil are similar to those of linseed oil (flaxseed oil).

The State of Wisconsin Industrial Hemp Program
Wisconsin Department of Agriculture Trade & Consumer Protection (DATCP) will promulgate rules establishing an industrial hemp program. The State of WI industrial hemp program must generally maximize opportunity for a person to plant, grow, cultivate, harvest, sample, test, process, transport, transfer, take possession of, sell, import, and export industrial hemp to the greatest extent authorized under federal law.

The authorizing legislation requires DATCP to do the following:

  • Ensure the quality of industrial hemp grown or processed in this state, the security of activities related to industrial hemp, and the safety of products produced from industrial hemp, including any necessary testing.
  • Verify adherence to laws and rules governing activities related to industrial hemp.
  • Enforce violations of laws and rules.
  • Require an initial fee from any person who plants, grows, or cultivates industrial hemp equal to the greater of $150 or $5 multiplied by the number of acres used to plant, grow, or cultivate industrial hemp, but not to exceed $1,000. An annual fee may also be imposed on any person whose industrial hemp activities are regulated by DATCP. This annual fee may not exceed an amount sufficient to cover DATCP costs to regulate those activities.
  • Ensure that certain information in its possession is confidential, except that this information must be made available to a law enforcement agency or law enforcement officer.

Pilot Program
DATCP is required to create a pilot program to study the growth, cultivation, and marketing of industrial hemp. The Act requires DATCP to issue licenses that authorize the planting, growing, cultivating, harvesting, sampling, testing, processing, transporting, transferring, taking possession, selling, importing, and exporting of industrial hemp. Such licenses do not expire unless the pilot program expires or the license is revoked.

Further questions that may be addressed by the new rule are:

  • How do I apply to grow hemp?
  • How long is my pilot production license good for?
  • Am I required to do anything else if I participate in the pilot program?
  • How do you know my field’s THC content?
  • What if my plants test above the acceptable 0.3% delta-9 threshold?
  • How does growing hemp affect my FSA and/or federal crop insurance contracts or program participation?
  • Can I grow hemp inside a greenhouse?
  • Can I see a list of hemp growers or hemp processors licensed in the state?
  • Do I need to notify the sheriff/local police?
  • Do I need to build a fence or put up signs around my field?
  • Can I grow hemp near a school, a town, or a major road? Are there restrictions on where I can grow it?
  • Do I need a license to process hemp?

AGRONOMIC CONSIDERATIONS
Besides work done in the early 20th century, there is little information on growing hemp in Wisconsin that is based on local research. The following information is gleaned from these references:

Purdue University Hemp
Kentucky Hemp Production
Cornell University Hemp
Canadian Hemp Trade Association Production eGuide
Finola oilseed hemp

When do you plant hemp?
Based on work done in neighboring states, planting done from mid-May to late-June resulted in highest yields with lower risk of frost injury.

What is the seeding rate?
General seeding recommendations is between 20-40 lbs per acre for grain production, and 40-60 lbs per acre for fiber production. A lot of factors go into determining the optimal seeding rate for your field, including the variety, seed purity and germ, local conditions, etc.

The end use of your hemp crop will dictate the seeding rate. When growing hemp for fiber only production, it is suggested the seeding rate should be double what is used for grain production. The reason for higher seeding rates is to ensure a higher quality fiber crop. Good quality hemp fiber comes from plants that are “pencil thin”. Higher seeding rates will ensure that there will be a high plant population with tall thin plants with longer internodes. Research is limited in Canada to determine proper seeding rates to achieve high yielding and good quality fiber. Low plant populations will not provide competition for early weed control. Hemp can have a high mortality rate under adverse growing conditions. Research has shown that 10% to 70% seed mortality can occur under varied climatic conditions. Based on observations, reasons for high mortality are generally attributed to:

  • Poor growing conditions at seeding
  • Seeding too deep
  • Cracking of the seed coat
  • Toxicity from high rates of seed placed fertilizer
  • Residual herbicides from previous crop

What are some seeding recommendations?

Most conventional drills and seeders will work for hemp. To enhance hemp plant stands:

  • Seed into warm soil
  • Seed into a firm seedbed with good soil to seed contact
  • Seed shallow, 1.25 cm (0.5 inches) to on 2.5 cm (1 inch) maximum
  • Do not seed deep into moisture in a dry year. In spite of being a moderately large seed, hemp will struggle to emerge from deep seeding
  • Avoid seeding before an abundance of precipitation is anticipated. Seed after a heavy rain rather than before
  • Although most seeding equipment will work for hemp it is important to monitor seeder output to avoid seed cracking. Cracking occurs in the manifolds when air volume is too high
  • Take into account germination rate. A common percentage of 70% germination is often used when calculating seeding rates. If spring seeding conditions are ideal this rate can be lowered
  • Avoid compaction from wheel tracks or other soil compaction, as with other crops, will show up under certain conditions
  • Avoid excessive trash that can keep soils cool and could cause hair pinning with disc drills

Can you plant hemp on hemp? How does it fit into a crop rotation?
According to the Canadian Hemp Trade Alliance (CHTA) “hemp fits in with typical crop rotation systems and with typical equipment that would already be found in a grain production system.”

Can I grow hemp organically?
Yes. On August 23, 2016, the National Organic Program (NOP) released this statement: “For hemp produced in the United States, only industrial hemp, produced in accordance with the 2014 Farm Bill, as articulated in the Statement of Principles on Industrial Hemp issued on August 12, 2016 by USDA, may be certified as organic, if produced in accordance with USDA organic regulations.” Some certification agencies will allow industrial hemp to be included in an organic rotation, so long as the growers are properly licensed under a pilot program. However, some certifiers may be taking a more hesitant approach, since there are many questions yet to be answered. Thus, farmers should talk to their certifier before making the decision to include this crop within their organic rotation. If growing industrial hemp, organic farmers will be required to do an organic seed search before using nonorganic seed.

Use practical organic farming practices such as a perennial clover or green manure plow down, with added manure to increase nutrient availability for rapid initial growth. Reduce any weed pressure by plowing and harrowing prior to sowing. The seedbed must be as fine and even as possible. Good soil, farming experience and proper nutrient levels are essential for successful organic oilseed hemp production.

Do you need to fertilize hemp?
Hemp has similar nutrient needs as canola and especially requires added nitrogen. Fertilize like rapeseed (Canola- Brassica napus) with 15% additional nitrogen. Conventional NPKS (nitrogen, phosphorus, potassium and sulfur) fertilization is recommended at the same levels required to grow rapeseed. Apply additional K and S wherever soils are deficient in these elements.

How/When do you harvest it?
Hemp can be grown for seed or fiber. Hemp grain harvesting is generally done by straight combining, however swathing is also used. Newer models of combines are best suited to handling hemp harvest and require minimal modifications. The new machines have bigger cylinders and cleaning area. In addition, newer combines can operate with headers at higher levels so all stands of hemp can be accommodated. Most new combines are now rotary design. Some new machines have the swath entering at the bottom of the cylinder. The draper header is preferred by growers.

The top third of the crop may be combined for grain while the plants are still “green” (70-90% seed head maturity). Harvesting while the crop is partially green will help minimize cutting and wrapping problems. The main disadvantage at harvest is plugging the combine with stems and other moist vegetative material. Dry field conditions are essential for a good harvest. However, a dead and desiccated crop will be more difficult to cut, more prone to wrapping and subsequent fire hazard. Grain moisture should be at least 10-15% at the time of harvest.

What kind of yield can I expect?
Yields can vary widely depending on the variety, local climatic conditions, cultivation method, and grower experience. For grain, new growers have reported yields between 250-700 lbs/acre. More experienced growers can expect between 800- 1,800+ lbs/acre. For fiber, the average yield for dual purpose crops (those varieties which are harvested for grain and fiber) is 0.75-2 tons/acre. For hemp produced solely for fiber, the average yield is between 3-5 tons per acre.

How deep are the roots?
Hemp has a large root capable of penetrating deep in the soil profile to recover nutrients that may be lost to many other crops, up to the 24-inch level.

What are some weed management strategies?
Given a good start, hemp can be an effective weed suppressant. Currently, there are no registered herbicides for weed control in hemp. A quick, even emergence is the key to effectively compete with weeds, by rapidly creating a dense leaf canopy within the first month of growth. Hemp will self thin to an optimal density, and it is better to have this crop compete with itself, rather than weeds. It is recommended to minimize weed pressure in the previous year and start with spring tilling and harrowing. Perennial forages or green manure plow downs are good preceding crops. Problem weeds may include wild buckwheat, wild oat, Amaranthus species, Chenopodium species, rapeseed, and other volunteer crops.

SEED
Where can I buy hemp seed from?
The Act requires DATCP to establish and administer an industrial hemp seed certification program, or designate a member of the Association of Official Seed Certifying Agencies or a successor organization to administer a seed certification program. This seed certification
program must include the testing and certification of THC concentrations in hemp plants. Participation in the certification program must be voluntary for growers and cultivators of industrial hemp. The Act also authorizes DATCP to seek federal approval to serve as an importer of industrial hemp seed. Importing seeds into Wisconsin to begin the hemp program may require permission from the U.S. DEA, which could affect the time when production can begin.

Other seed-related questions that may be addressed by the rules are:

  • Can I save seed for planting the following year?
  • Do I need a seed permit to sell hemp seed in Wisconsin?
  • Can I breed a new variety of hemp for Wisconsin?

GRAIN HANDLING
Do I need a grain buyer’s license to buy hemp grain?
Yes, if you are buying hemp grain with the purpose of reselling the grain or products made from the grain. In addition to a license, a bond must be acquired.

Sanitation

  1. Hemp is sold as a raw food so avoiding contamination is extremely important.
  2. All harvest related equipment should be cleaned out prior to harvest to ensure no contamination occurs from other crop types that are difficult to clean out of hemp.
  3. Combine divergent crops like canola or soybeans before combining hemp. This cleans out the combine and these crops are easily removed if contamination occurs.
  4. Clean grain as soon as possible to maintain grain quality and ensure safe storage. Inspect trucks for cleanliness before loading clean grain that is destined for the processor.
  5. For maximum shelf life, grain should be stored in a clean, dry location. Storage temperatures in excess of 75° Fahrenheit for a sustained period of time may cause rancidity and separation of the soluble and insoluble proteins.

Drying

  1. Hemp is combined at a moisture content of 10 to 20% moisture. The majority of the moisture comes from broken plant material, immature seeds and seeds enclosed in bracts. Dockage will range from 10 to 20%. The wetter the sample, the more urgent the drying process is. Drying should begin within hours of harvest. Heated air grain dryers and aeration can be used for drying the seed down
  2. The industry has accepted 10% moisture as dry. A safer level is 8 or 9%. Percent moisture requirement should be checked with contractor.
  3. Hemp grain generally has a lot of bracts and broken plant parts that are higher in moisture than the grain. Once drying begins these plant parts dry quickly and the speed at which the grain dries also increases at the end of the drying cycle.
  4. Monitor grain dryer temperatures to ensure the seed and seed oil quality is not compromised. Overheating the seed can cause the seed to turn yellow and discount the oil quality.
  5. Use grain drying when seed moisture is over 13 or 14%
  6. Monitor the dryer operation closely. Batch and continuous flow dryers are the most commonly used. Augers should be run full and slow to prevent cracking of the grain.
  7. Use heat of 150 to 160 degrees F for the first ½ of the drying period and then use 120 to 130 degrees to finish off the drying.

Cleaning

  1. Cleaning is required to remove contaminants such as weed seeds, plant parts and insects and it should be conducted as soon as possible after harvest. More importantly, cleaning removes cracked seeds resulting from combining.
  2. When cracked seeds are exposed to the air it causes oxidized rancidity of the oil which will contaminate the other seeds in the seed lot. This gives the hemp seed an undesirable taste and shortens the shelf life.

Economics and Marketing
Further marketing information can be found at:
Alberta Agriculture and Forestry

Who will buy my hemp if I grow it?
The market is limited and constantly in flux for hemp in the U.S. due to many different factors. We encourage interested individuals to contact a hemp trade association to learn more about marketing opportunities.

How much can I sell my hemp for?
Prices for hemp grain are widely fluctuating in the U.S. specifically due to the infancy and constant development of the industry. According to the Alberta Agriculture and Forestry Department, the average hemp grain price in 2015 in Alberta was $0.74 per pound. Typical returns for hemp grain in the U.S. have been between $0.40-0.70 per pound for conventional, and $0.75-1.00 per pound for organic. Due to the volatile nature of the current U.S. hemp industry, growers are advised to secure a contract before they plant.

What is the cost per acre?
The Alberta Agriculture and Forestry Department reported an average total production cost for hemp seed grown on dryland in 2015 at $409 per acre. With an average grain yield of 1,074 pounds per acre, that amounted to $0.38 per pound of hemp seed produced.

In Minnesota, hemp seed prices are widely variable based on the variety and the source. Imported seed has additional shipping and customs fees above and beyond domestically produced seed. Farmers should also consider the possibility of needing to buy or rent new harvesting equipment if they grow hemp. In 2016, hemp producers in Minnesota reported costs per acre between $970-$2,500 per acre. In 2017, initial reports indicate production costs of between $300-$600 per acre (does not include land cost).

Other questions that may be addressed by the new rules:

  • Who will process my hemp in WI?
  • Where are processors located in WI?
  • Can I export hemp product to other countries?
  • Can I sell grain or fiber to other states?
  • Can I sell seed to other states?
  • Are there any grants that I can get?
  • Can I grow hemp under contract with someone else?

Feed

Can I feed hemp to my livestock?
Hemp is not currently an approved ingredient for commercial animal feed. Therefore, hemp material cannot be sold as animal feed.

Other sources of information
Wisconsin Hemp 101: Educational Seminar
Date: Jan 30, 2018 6:30PM
Venue: Chippewa Valley Technical College – Eau Claire

Congressional Research Report “Hemp as an Agricultural Commodity

Minnesota Department of Agriculture
Vote Hemp
Hemp Industries Association
National Hemp Association

Winners of the 2017 WI Soybean Contest are Announced

The 1st place winner in Division 4, RnK DeVoe Farms of Monroe, grew DuPont Pioneer P31T77R and harvested 93.15 bu/a.  In second place, Bahr Farms Inc. of Darlington grew Asgrow AG2535 and harvested 90.19 bu/a.  In Division 3, Steve Wilkens of Random Lake won 1st place with NK S21-M7 Brand at 89.39 bu/a, and in 2nd place, Jim Salentine of Luxemburg harvested 75.19 bu/a with Steyer 1401L.  In Division 2, Bork Farms of Grand Marsh achieved 91.49 bu/a from LG Seeds C2020R2 for first place.  In 2nd place, Peavey Farms of Woodville harvested 76.47 bu/a from Croplan R2C1400 soybeans.  In Division 1 at 67.02 bu/a was David Lundgren from Amery who planted Croplan R2C1572.  2nd place winner in Division 1 was Dawn Lundgren from Amery.  She harvested 64.22 bu/a from DuPont Pioneer P16A35X.

Bork Farms of Grand Marsh was also the winner of the Soybean Quality contest with 2,970 pounds of protein plus oil per acre.

The contest is sponsored by the WI Soybean Program and organized to encourage the development of new and innovative management practices and to show the importance of using sound cultural practices in WI soybean production.

For more information please contact Shawn Conley, WI State Soybean Specialist at 608-262-7975 or spconley@wisc.edu

Best Management Practices for Growing Second or Third Year Soybeans

Originally Coauthored by: Shawn P. Conley, Seth Naeve and John Gaska December 14, 2016.

Modified by S.P.Conley 1/22/18.

Before we start, we fully acknowledge our title “Best management practices for growing second or third year soybeans” is a bit misleading as we do not advocate this practice (its not a BMP!) but we thought we could sucker you into reading this article if it had an enticing title!
Our main reason for updating this 2017 article stems from growers questioning their 2018 bottom line and USDA’s announcement that U.S. soybean acres in 2018 will surpass U.S. corn acres.  These acres have to come from somewhere and many of them will be from second-year soybean.
With all of that being said here are some recommendations to consider:
  • Balancing short-term versus long-term profitability (i.e. economic sustainability). Short-term profitability may drive some farmers to consider planting more soybeans in 2018.  Data from our long -term rotation experiment clearly shows the benefit of crop rotation to the soybean crop. It is amazing that after 5 years of corn, it only took 3 years of continuous soybean for the yield to drop to within 7% of continuous soybean (20+ years) yield levels whereas 2nd year soybean yielded within 5% of soybean in a corn-soybean rotation. We could hypothesize then that the yield of the 3rd year of continuous soybean (in our experiment) would be similar to a 2ndyear of soybean in a corn soybean (C-S-S) rotation. Our data clearly shows that 3 or more years of continuous soybean gives you a 7+ bu per acre hit when compared to a corn-soy rotation and moves you close to that of continuous soybean. In short, you are setting your long-term profitability up for a hit. So what do you do? If it were my land I would stick to my rotations on my owned land and consider 2nd year soybeans on the rented ground.
  • Be aware that soybean after soybean will alter the pest complexes in your fields.  Some of these alterations may take years to undo as you will be making a long-term impact on your soil and resulting soil health. Also don’t automatically think that simply adding a cover crop to this S-S rotation will “fix” these issues.
  •  Plant a different variety than was planted in that field last year and make sure it has strong disease resistance traits to the problems you have in that field! Every variety has a weakness and planting the same variety on the same land 2 years in a row will expose that weakness.  Note that these varieties must be truly different.  The same bean in a different color bag will greatly increase your risk of disease losses.  Please see our 2017 Wisconsin Soybean Variety Performance Trials for information.
  • Test for SCN and select SCN resistant varieties. SCN proliferates in long-term soybean cropping systems.
  • Be prepared to scout your fields more intensively to get ahead of any disease problems. Increased disease pressure may provide an opportunity to see yield responses from fungicides and insecticides.  You may need to include these costs into your original economic decisions.  
  •  Keep seeding rates lower if white mold was a problem in the field 
  • Use a seed treatment at the max a.i. fungicide rate. 
  •  Use a pre-emergence herbicide and use multiple modes of action. If you had weed escapes, expect even larger problems in soybean after soybean. 
  • Soil sample and replace K if needed: I know growers are going to want to cut back on inputs but 2017 brought us above trend yield. An 80 bushel soybean crop meant you removed ~98 pounds per acre of K20 equivalent fertilizer. Growers often routinely rely on carryover fertilizers for soybean when rotated with well-fertilized corn.  Soybean after soybean may require additional fertilizer, especially K.

Finalists for the 2017 WI Soybean Yield Contest are Announced

The 2017 soybean production year did not produce the record yields that we saw in 2016 but was above trend for most Wisconsin farmers. Changes to our entry form and rules led to greater interest and participation in the 2017 WSA/WSMB Soybean Yield Contest. The top two entries in each division (in no particular order) were:

Division 4:

  • Kevin and Dale Bahr, Darlington (planted Asgrow AG2535)
  • Rick DeVoe, Monroe (planted DuPont Pioneer P31T77R)

Division 3:

  • Steve Wilkens, Random Lake (planted NK S21-M7 Brand)
  • Jim Salentine, Luxemburg (planted Steyer 1401L)

Division 2:

  • Scott Peavey, Woodville (planted Croplan R2C1400)
  • Kevin Bork, Grand Marsh (planted LG Seeds C2020R2)

Division 1:

  • Dawn Lundgren, Amery (planted DuPont Pioneer P16A35X)
  • David Lundgren, Amery (planted Croplan R2C1572)

The Soybean Quality Contest was optional for any Soybean Yield Contest entrant.  There are no geographical divisions for the Quality Contest.  One cash award will be presented statewide to the highest protein plus oil yield per acre (measured in lbs. per acre). The finalists for the Soybean Quality Contest are:

  • Rick DeVoe, Monroe (planted DuPont Pioneer P31T77R)
  • Kevin Bork, Grand Marsh (planted LG Seeds C2020R2)

The final ranking and awards will be presented at the Corn Soy Expo to be held at the Kalahari Convention Center, Wisconsin Dells on Thursday February 1st during the WSA/WSMB annual meeting.

The contest is sponsored by the WI Soybean Program and organized to encourage the development of new and innovative management practices and to show the importance of using sound cultural practices in WI soybean production.

For more information please contact Shawn Conley, WI State Soybean Specialist at 608-262-7975 or spconley@wisc.edu

Industrial Hemp in Wisconsin: The First Steps!

The University of Wisconsin Madison and UW Extension has been inundated with questions related to industrial hemp production since the passing of the 2017 Wisconsin Act 100. The below information was authored by Patrick Robinson, Associate Dean Department of Agriculture and Natural Resources, Cooperative Extension, University of Wisconsin Extension. Patrick recognizes William (Bill) Barker Associate Dean for Research, The College of Agricultural and Life Sciences, The University of Wisconsin – Madison as a significant contributor to this article. Patrick also recognizes DATCP and NIFA sources as some language was copied verbatim for legal purposes.

  • Wisconsin growers will be able to grow and process industrial hemp under 2017 Wisconsin Act 100, a law recently passed by the Legislature and signed by the Governor. The law directs the Wisconsin Department of Agriculture, Trade and Consumer Protection to write an emergency administrative rule that will spell out the details of the program, including requirements for growers. This is a pilot program to study growth, cultivation and marketing of industrial hemp.  Participants will be required to obtain a license from DATCP to grow hemp, and to pass a background check before receiving a license. DATCP will complete the emergency rule by March 2, 2018. This rule will remain in effect until July 2020, or until the permanent administrative rule is completed – whichever comes earlier. As of today, the rules and pilot program have not been developed. More can be found here: https://datcp.wi.gov/Pages/Programs_Services/IndustrialHemp.aspx.
  • USDA NIFA is authorized to support industrial hemp researchwhere such activity complies with state law. Further, the researcher must either 1) be an institution of higher education or state department of agriculture, 2) or grow the industrial hemp under the auspices of a state agricultural pilot program. More can be found here: https://nifa.usda.gov/industrial-hemp.
  • Section 7606 of the 2014 Farm Bill did not alter the approval process for new drug applications or any other authorities of the FDA, nor does it alter the requirements of the Controlled Substances Act that apply to the manufacture, distribution, and dispensing of drug products containing controlled substances. Whether hemp may be grown for food and pharmaceutical products remains a question for the FDA and/or the DEA.
  • State agricultural pilot programs must provide for State registration and certification of sites used for growing or cultivating industrial hemp.
  • Importing seeds into Wisconsin to begin the hemp program may require permission from the U.S. Drug Enforcement Agency, which could affect the time when production can begin.

Please be patient as this is a very new and dynamic area for both WI farmers and legal system. Please stay tuned as updates will be provided as they come to light. 

RR2Y® versus Xtend® Soybean Cultivar Performance in 2017…. A Lesson in Fuzziness

Authored by: Shawn P. Conley and Damon Smith

Tis the season of early booking promotions and seed discounts. These programs seem to get earlier and earlier each year just like Christmas music! Pretty soon growers will be getting a 25% discount to book their 2021 seed orders on a variety yet to be named…. Nevertheless, our 2017 Wisconsin Soybean Variety Performance Trials are posted and I wanted to give a brief update on the relative performance of RR2Y® versus Xtend® (RR2X) soybean platforms from this growing season. As you may recall, we tackled this topic last year in an article entitled: New Traits Don’t Automatically Translate to Highest Yield! I don’t want to rehash the whole story but in short we wanted to remind growers of the following:

  1. New doesn’t always mean it is automatically better.
  2. Remember – every variety must stand on its own
  3. RR2X soybeans are a stack of herbicide traits and not yield traits (i.e… these traits protect yield, not enhance yield). Remember this point with all pest management traits!
  4. The RR2Y suite of varieties yielded 1.8 bu/acre better than Xtend in 2016.

So how did these platforms fare in 2017? Well, the story isn’t quite as clean and straightforward as 2016, when we had record yields across the state. First, we lost two of our variety performance trial sites in the southern part of WI. One was our Platteville no-till site that received such heavy and pounding rain that is sealed the soil. Yes you heard me correct a no-till site was crusted so badly our beans could not emerge. I am grateful there is no such thing as climate change so there is no chance this will ever happen to me again…. The other site was lost to off-target movement of herbicide. That left our flagship Arlington location as the only southern location and well…..that got hammered by white mold (stay tuned for more on this topic). Fortunately, our central and north central locations fared a bit better though we did get white mold at two irrigated sites; Hancock and Chippewa Falls (still stay tuned for this as well).

So what happened…..

In our statewide pooled data-set, we saw RR2Y® varieties yielding 2 bu/acre higher than the Xtend® varieties; a significantly higher yield (Figure 1). As stated above, this response difference is not as clean and straightforward as last year given the lost sites and white mold at three locations (almost there).


Figure 1. Pooled Herbicide Platform Performance Across Southern, Central, and North Central WI in 2017.

Within each region, we do see slightly more RR2Y® varieties having a star (starred varieties are not significantly different (0.10 level) than the highest yielding cultivar) over Xtend® varieties (Figure 2); though our data does show farmers have several varietal options under both platforms. ****Remember point 2 above each variety must stand on its own.


Figure 2. 2017 Regional Starred Varieties as a % of Varieties of Each Platform

What drove this yield disparity in 2017? Increased white mold incidence may have been the culprit. Across the three locations where we observed white mold (Arlington, Hancock, Chippewa Falls) we saw 8% greater incidence in the Xtend® suite of varieties than the RR2Y® (Figure 3).


Figure 3. Pooled White Mold Incidence at Alington, Hancock, and Chippewa Falls Sites Across Herbicide Platforms 2017.

Varieties across platforms varied greatly in white mold incidence and yield as the range of white mold in the trials was 1 to 95% (Figure 4).

Figure 4. Variation in white mold incidence among varieties and herbicide platforms.

Given that the average incidence of white mold at these three locations was 29%, an 8% difference between these platforms could easily explain the yield disparity. Remember, that every 10% increase in white mold incidence leads to 2-5 bu/a loss. Thus at these locations yield loss at 29% incidence is estimated to range from 6-15 bu/acre. For more information on individual variety performance and white mold ratings consult the 2017 Wisconsin Soybean Variety Performance Trials.

Lastly as you select soybean varieties for 2018 make sure to balance yielddisease risk, and the latest dicamba regulations for your specific farm needs. It is no big industry secret that margins are going to be tight again in 2018…choose wisely!

Fall is Still a Good Time to Sample for SCN and Other Plant Parasitic Nematodes

Ann MacGuidwin, Damon Smith and Shawn P. Conley 
The WI Soybean Marketing Board (WSMB) sponsors free nematode testing to help producers stay ahead of the most important nematode pest of soybean, the soybean cyst nematode (SCN). Eggs of SCN persist in the soil between soybean crops so a sample can be submitted any time that is convenient. The soil test report indicates the number of eggs in the sample and is useful for selecting the right variety for the next soybean crop. Retests of fields planted with SCN-resistant varieties over multiple years shows how the nematode population is responding to variety resistance and provides an early warning should the nematode population adapt to host genetics.


In the spring of 2012, the WSMB expanded the nematode testing program to include other pest nematodes in addition to SCN. These nematodes are less damaging to soybean than SCN but can cause enough yield loss to warrant treatment. As is the case for SCN, there are no rescue treatments for nematodes so the primary purpose of this year’s soil test is to plan for next year’s crop. Soil samples collected in corn for nematode analysis have predictive value for explaining yield if they are collected before the corn V6 growth stage. Sampling early in the season will provide information about the risk potential for the current corn crop AND the next soybean crop.

The assays used to recover nematode pests other than SCN in soil require that the nematodes are alive. So, it is important to keep the samples moist and at least room temperature cool. Collecting a sample that includes multiple cores ensures that there will be plenty of root pieces to assay. It is not necessary to include live plants in the sample. The soil test report will indicate which pest nematodes are present and at what quantities and their damage potential to soybean and corn based on the numbers recovered.  

For more information on SCN testing and management practices or to request a free soil sample test kits please contact: Jillene Fisch at (
freescntest@mailplus.wisc.edu) or at 608-262-1390.

Remember the first step in fixing a nematode problem is to know if you have one! The WSMB sponsored nematode testing program provides you that opportunity.