Best Management Practices for Growing Second Year Soybeans

Coauthored by: Shawn P. Conley, Seth Naeve and John Gaska 

Before we start, we fully acknowledge our title “Best management practices for growing second 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 writing this article stems from growers questioning their 2017 bottom line.  This issue was highlighted in the article written by Gary Schnitkey and Darrel Good entitled 2017 Crop Budgets and Current Prices Say Switch to Soybeans and Expect Low Returns. It is thought that farmers may plant 5 million more acres of soybean in 2017 than they did in 2016 based on current corn:soybean price ratios and input prices. Those 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 2017.  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 soybean for the yield to drop to continuous soybean (20+ years) yield levels. Good news is that 2^nd year soybean yielded the same as soybean in a corn-soybean rotation. We could hypothesize then that the yield of the 3^rd year of continuous soybean (in our experiment) would be similar to a 2^nd year 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 4+ 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 2^nd 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 2016 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 2016 brought us record yields. 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 2016 WSA Soybean Yield Contest are Announced

The Wisconsin 2016 growing season was one for the record books indeed! The National Agricultural Statistics Service projects the statewide average soybean yield in WI to be a record of 55 BPA. Similarly overall production is expected to be another record at 107 million bushels. The great yields also led to a great contest. Please join me in congratulating the below finalists.

The top two entries in each division (listed in no particular order) were:

Division 4: 

• Rick DeVoe, Monroe (planted DuPont Pioneer P31T77R)
• Kevin Bahr, Belmont (planted Asgrow AG2535)
• *WI Bean Team (Adam Gaspar, Steve Vosberg), Madison (planted DuPont Pioneer P28T33R)

*The WI Bean Team is ineligible for official prizes as they are grad students of Dr. Conley; however, their efforts are still unofficially recognized.  

Division 3:

• Jim Salentine, Luxemburg (planted Steyer 1401L)
• David Wilkens, Random Lake (planted NK S20-T6 Brand)

Division 2:

• Thad Sparby, Arkdale (planted FS HiSOY HS 19A50) 
• Irvin Osterloh, Arkdale (planted FS HiSOY HS 23L50) 

Division 1: 

• Dawn Lundgren, Amery (planted Croplan R2C1400) 
• David Lundgren, Amery (planted Croplan R2C1572) 

New for 2016 was the Soybean Quality Contest.  It was optional for any Soybean Yield Contest entrants.  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:

• Dawn Lundgren, Amery (planted Croplan R2C1400) 
• Thad Sparby, Arkdale (planted FS HiSOY HS 19A50) 

The final ranking and awards will be presented at the 2017 Corn Soy Expo to be held at the Kalahari Convention Center, Wisconsin Dells on Thursday February 2nd 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

New Traits Don't Automatically Translate to Highest Yield!

Last weeks announcement by the EPA to register Dicamba formulations for use on Dicamba Tolerant Crops has the soybean world abuzz and for once that buzz isn't about pollinators! Many of my weed scientist colleagues across the country will be discussing best management practices (BMP's) for introducing this technology into our agricultural landscape and will put forward recommendations to prolong the shelf-life of this technology. Here is one such example from UNL entitled: Understanding the Roundup Ready 2 Xtend SoybeanWeed Management System. ***Side bar....I decided to highlight this article since UNL never has any highlights in WI and Purdue and IL are like playing the J.V. squad.***

In this brief article I would just like to highlight four points to consider when making soybean variety selection choices for 2017. 

1. New doesn't always mean it is automatically better. The WI Soybean program evaluated 200 RR2Y (Roundup Ready 2 YieldⓇ) and 47 RR2X (Roundup Ready 2 XtendⓇ) varieties in 2016. On average across all varieties and regions RR2Y out-yielded RR2X by a significant +1.8 BPA (Figure 1.)
2. Remember every variety must stand on its own. Use independent trial data and pick varieties that not only perform well (we call them **starred varieties**) but also have the traits you are interested in (e.g. herbicide tolerance). Please see the 2016 Wisconsin Soybean Variety Performance Trials for individual variety performance as we have RR2X varieties starred in each region. 
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. Hey Mr. Ivory Tower if I don't use this technology my yield loss will be a lot more than 1.8 bu per acre. I am fully aware of the amaranthus spp. train wreck across much of the corn belt and mid-south. We are starting to see herbicide resistance move across Wisconsin as well. I just want to reiterate #2 above that every variety must stand on its own as well as remind growers to use multiple modes of action and consider incorporating other traits such as Liberty Link soybeans into your soybean weed management plans. All of the data and models I have seen suggest that the Dicamba tolerant crops shelf-life will be much shorter than the original RR if we don't mange this technology correctly. 

   

   Figure 1. Pooled Herbicide Trait Performance Across WI

Start Managing for Fusarium Head Blight Now Before You Plant the 2016/17 Crop

By Shawn P. Conley and Damon Smith

Most WI winter wheat growers dodged the Fusarium head blight (FHB or scab) bullet in 2016; though many farmers especially those in SW WI became so disgusted with dockage and rejections in both 2014 and 2015 they didn't plant a single acre this year. Therefore as we prepare to put the 2017 wheat crop into the ground here are a few considerations for managing FHB before we drop a single seed.

1.      Crop rotation matters. Data from our long-term rotation studies indicate that wheat following soybean provides the greatest yields. The next best options are wheat following corn silage (6.5% less) then corn for grain (21% less). Wheat following alfalfa or another leguminous crop are also good options, though the N credits following alfalfa may best be served going to corn. Furthermore, background fungal pressure (residue on and in soil) from the FHB fungus will be greater following corn then soybean or another legume, however know that spores that infect your wheat crop can arrive from  outside the field. Please click to see more information on the Top 8 Recommendations for Winter Wheat Establishment in 2016.  

2.      Variety selection matters. Data from our 2015 and 2016 WI Winter Wheat Performance Test shows variable yield and disease performance among the varieties listed. Select those varieties that have both good to excellent FHB (2015) and Stripe Rust (2016) resistance and high yield. When evaluating disease resistance, low numbers for both incidence and severity can be helpful, but the major focus should be placed on  incidence (measure of the number of symptomatic plants in a stand).

3.      Application timing matters. One of the biggest challenges year in and year out is improper fungicide application timing. Our data suggests that on susceptible (Hopewell) or moderately susceptible varieties (Kaskaskia) equal efficacy of the fungicide Prosaro at a rate of 6.5 fl oz/acre can be achieved when applied between Feekes 10.5.1 (anthesis) and 5 days after anthesis. Given the variability of head emergence and anthesis across a landscape it may prove best to wait a few days until the whole field is flowering than to apply too soon.  If the extruded anthers have turned from yellow to white across the whole field then you are likely too late. Remember it roughly takes a wheat head 7 days to completely self-pollinate.

Fusarium head blight incidence ratings for four soft red winter wheat varieties treated with Prosaro SC fungicide at 6.5 fl oz/a at anthesis (Feekes 10.5.1), five days after anthesis, or not treated in Wisconsin in 2015.
	Hopewell (Susceptible)	Kaskaskia (Moderately Susceptible)	Pro 200 (Moderately Resistant)	Sunburst (Moderately Resistant)
Prosaro SC @ 6.5 fl oz/a (Feekes 10.5.1)	9.5b	2b	0.5	4
Prosaro SC @ 6.5 fl oz/a (5 days after Feekes 10.5.1)	7.5b	5.25b	2.75	2.75
Non-treated control	31.25a	17.5a	3	1.5
Pr>F	0.01	0.01	ns	ns
LSD	6.44	6.44	ns	ns

4.      Choose the right fungicide class. Make sure you use the appropriate fungicide product and class to manage FHB. The label for products containing strobilurin active ingredients (FRAC group 11) ends prior to flowering. Late application can actually lead to increased mycotoxin levels. Triazole containing products (FRAC group 3) are recommended for FHB control. For a list of products and efficacy ratings, visit the Field Crops Fungicide Information Page. 

5.      Harvest timing and flash drying. The word on the street is that if FHB appears to be a problem in 2017 elevators will push growers to harvest early (18% moisture or higher) and subsequently dry grain to mitigate mycotoxin levels. While drying grain to 13% or less moisture is a good storage practice, know this process may kill the pathogen but any mycotoxin levels already in the grain will not dissipate. Vomitoxin is a very stable molecule and IS NOT degraded by heat, freezing, or drying.    

Small Grains Harvest and Combine Fires

From John Shutske:Professor & Extension Specialist; Biological Systems Engineering

It looks like wheat harvest is rolling in parts of the state.   I saw a post from a friend in New Glarus saying they’d started late yesterday. Just a quick reminder on combine fire prevention and protection --  “Protection,” because SOME machines will burn regardless of how hard you work at it.  So you need to know what to do to minimize the damage.  Over the years I (or my former students) have done a bunch of investigative work on about 12,000 fires (combines, tractors and other specialty harvesters).  We’ve learned a lot….

See:

http://ipcm.wisc.edu/blog/2013/10/learn-not-to-burn-during-this-busy-harvest-season/

http://americanfarmservices.com/information/heavy-equipment-and-combine-fires/

http://nasdonline.org/static_content/documents/1494/d001294.pdf

Here are some specific reminders:

1.  Keep the engine compartment as clean and clear of debris as possible.  Caked/oily residue means there’s a leak someplace.  Fix it. 
2. Listen closely for unusual noises and pay attention to warning lights and sensors that could indicate bearing/belt/and other drive component issues.  Fix them. 
3. Many combine fires are ignited by the electrical system – blown fuses, flickering lighting, etc. are all signs that you might have damage.  
4. The ABC dry chemical fire extinguisher is probably still the most cost-effective and overall effective type of extinguisher.  The bigger the better (at least 10 pounds).  Mount extinguishers (recommend at least two ten-pounders) where they can be grabbed quickly in the cab AND/OR from the ground.  
5. If a combine does catch fire, pull it away from any standing crop quickly.  Shut off the engine.  The longer the fire burns, the more difficult it will be to put it out.  If the engine is left running, it will be almost impossible to extinguish (even if the fire department shows up)! 
6. Grab your extinguisher if time allows and get out.  Call for help.  It is not always possible to put out a vehicle fire with a handheld extinguisher.  A second one is often needed, even on a smaller fire. 
7. Always consider PERSONAL safety.  A combine fire that gets into a fuel, oil, or other flammable liquid system will burn hot.  Even more so if a tire is involved.   A machine can be replaced.  A life cannot. 
8. If you’ve used an extinguisher (even for a short burst), it MUST be recharged.  If you’re not sure where to recharge and re-tag your extinguisher, call your fire department.

 

Small Grains Harvest and Combine Fires

From John Shutske:Professor & Extension Specialist; Biological Systems Engineering

It looks like wheat harvest is rolling in parts of the state.   I saw a post from a friend in New Glarus saying they’d started late yesterday. Just a quick reminder on combine fire prevention and protection --  “Protection,” because SOME machines will burn regardless of how hard you work at it.  So you need to know what to do to minimize the damage.  Over the years I (or my former students) have done a bunch of investigative work on about 12,000 fires (combines, tractors and other specialty harvesters).  We’ve learned a lot….

See:

http://ipcm.wisc.edu/blog/2013/10/learn-not-to-burn-during-this-busy-harvest-season/

http://americanfarmservices.com/information/heavy-equipment-and-combine-fires/

http://nasdonline.org/static_content/documents/1494/d001294.pdf

Here are some specific reminders:

1.  Keep the engine compartment as clean and clear of debris as possible.  Caked/oily residue means there’s a leak someplace.  Fix it. 
2. Listen closely for unusual noises and pay attention to warning lights and sensors that could indicate bearing/belt/and other drive component issues.  Fix them. 
3. Many combine fires are ignited by the electrical system – blown fuses, flickering lighting, etc. are all signs that you might have damage.  
4. The ABC dry chemical fire extinguisher is probably still the most cost-effective and overall effective type of extinguisher.  The bigger the better (at least 10 pounds).  Mount extinguishers (recommend at least two ten-pounders) where they can be grabbed quickly in the cab AND/OR from the ground.  
5. If a combine does catch fire, pull it away from any standing crop quickly.  Shut off the engine.  The longer the fire burns, the more difficult it will be to put it out.  If the engine is left running, it will be almost impossible to extinguish (even if the fire department shows up)! 
6. Grab your extinguisher if time allows and get out.  Call for help.  It is not always possible to put out a vehicle fire with a handheld extinguisher.  A second one is often needed, even on a smaller fire. 
7. Always consider PERSONAL safety.  A combine fire that gets into a fuel, oil, or other flammable liquid system will burn hot.  Even more so if a tire is involved.   A machine can be replaced.  A life cannot. 
8. If you’ve used an extinguisher (even for a short burst), it MUST be recharged.  If you’re not sure where to recharge and re-tag your extinguisher, call your fire department.

 

Some Risk for Wheat Crop Injury From Saturday's Cold Temps

Saturday mornings cold temperature may lead to crop injury in low lying areas across Southern WI. Based on the development in our wheat plots the highest risk for yield loss would likely come in the southern tier of WI counties. The wheat at our southern locations are either at the Feekes 8 (flag leaf visible) or 9 (flag leaf ligule and collar visible) crop growth stage dependent upon variety. 

 

Image 1. Feekes 9 crop growth stage at Arlington WI on 5/16/16.

Crop injury at these growth stages would occur in the 24 to 28 (duration of up to two hours) degree F temperature range. We did not see this temperature extreme at our Arlington location (Image 2; low temp of 30.5) however I have heard reports of extended cold temperatures in the sub 28 degree F range.   

Image 2. Arlington WI weather data for the last week. Image 2. Arlington WI weather data for the last week.

The two types of crop injury I would be concerned about include stem damage and spikelet (head) injury. In Image 3 below you can see the brown discoloration and water soaking to wheat stems caused by freeze injury. This  injury eventually lead to severe lodging among select varieties (Image 4). If you see this type of injury it would be best to take this field as a forage crop ASAP. 

Image 3. Freeze damage to wheat stem.

Image 4. Subtle difference is crop growth stage led to severe lodging due to freeze injury.

The other type of injury would be direct damage to the wheat head. Peel back the boot and expose the wheat head. If healthy individual florets on the spikelet will appear pale green (Image 5). If they begin to appear water-soaked or off colored (brown) then crop injury occurred).  

Image 5. Healthy spikelet and florets.

For more detailed information I have attached a link to a publication entitled Spring Freeze Injury to Kansas Wheat.  For ease I have also removed a table from that publication to stress the importance of growth stage on damage potential  (Table 1).

Table 1.  Wheat Resistance to Freeze Injury (From: Spring Freeze Injury to Kansas Wheat)