Project Details:

Double Crop Rotation -- Improving Yield and Profitability and Reducing SCN

Parent Project: This is the first year of this project.
Checkoff Organization:Illinois Soybean Association
Categories:Agronomy, Crop management systems, Cover Crops
Organization Project Code:
Project Year:2019
Lead Principal Investigator:Jason Bond (Southern Illinois University at Carbondale)
Co-Principal Investigators:
Charleston/Orwig (Charleston/Orwig)
Jeff Wessel (Corn Belt Ag Services, LLC)
John Baily (JCB Ag Research)
Quentin Rund (PAQ Interactive, INC.)
John Pike (Pike Ag)
Terry Wyciskalla (Wyciskalla Consulting)
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Contributing Organizations

Funding Institutions

Information and Results

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Project Summary

Yield and profitability of double crop (DC) systems could increase with use of better management practices and adapted varieties, and this also would allow the DC system to succeed farther north. Planting soybeans earlier can increase yield as much as one bushel per acre per day, and wheat in the rotation can significantly reduce SCN egg counts. This project will develop a double-crop production guide for optimizing DC profitability, validate how wheat straw reduces SCN threat to soybeans.

Project Objectives

Show how adopting the early wheat system (planting ultra-early varieties and harvesting at 20%) leads to earlier soybean planting and high soybean yields and further expansion North in Illinois.

Examine how wheat straw reduces SCN egg counts in the soil

Provide support the Wheat Soybean Double Crop Conference

Build awareness by leveraging current SCN coalition materials through a range of media channels

Write and Publish a Double Crop Guide

Project Deliverables

Activity 1: Double Crop Conference
Provide supplemental funding to support the cost of the annual Illinois Double Crop Conference scheduled for February 6, 2019, in Mt. Vernon. The Illinois Soybean Association (ISA) and Illinois Wheat Association partner to develop, promote and the share cost of the event including site, coffee breaks, meal, and speaker fees and expenses. ISA’s technical consultant assists with program planning, finding speakers, collecting speaker collateral material (name and affiliation, bio, photo, talk title and talk description) and serves as an emcee at the event and assisting as needed.

Tentative program and speakers include:
• Marketing outlook: Joe (Todd) Hubbs, U of I
• Wheat management: Carrie Knott, U of KY
• Economics and profitability of double cropping: Gary Schnitkey, Economist, U of I
• Double cropping – diseases to look out for: Nathan Kleczewski, Field Crops Pathologist and Extension Specialist
• Improving Double-Crop Soybean Production and Profits - Shaun Casteel, Purdue University
• What the wheat milling industry demands in quality wheat, Carl Schwinke, Siemer Milling
• Double cropping farmer panel

Activity 2: Illinois Double Crop Production Guide
Develop and produce a Double Crop Production Guide highlighting the advantages and best management practices of double crop rotations, and accompanied by shorter 4-page insert in Illinois Field & Bean magazine.

Title: Systematic Strategies for Increasing Yield in the Wheat Soybean Double Crop Rotation

Guide Layout:
• 8.5 x 11” stitched
• Page count – 16 sheets: 1 x 4 page spread covers, 6 sheets/12 pages for wheat and 6 sheets/12 pages for soybeans
Follows the Six Secrets publishing model of 2 column pages and a mix of short paragraphs, bullets, images and graphics
• An advisory panel of wheat and soybean experts will design and review content. ISA’s technical advisor will develop and write the content. Charleston Orwig will format and edit contents.
• Printing costs will be raised from sponsors and extra copies distributed through sponsors
• PDF, flipbook, eBook and printed

Content Development:
• Booklet will follow the same approach as ISA’s soybean production guide with a format based on making strategic production decisions and best management practices. It is not intended to be a complete resource since much of that information is easily available on the internet from multiple sources. It will be formatted based on the recent Six Secrets insert in Field & Bean.
• Illinois Soybean and Illinois Wheat Associations will organize a panel of experts to outline the production decisions and actions to include the booklet and then review content.
• ISA Technical Coordinator will be responsible for organizing the wheat and soybean information into a draft document that will be passed on to Charleston Orwig.
• ISA Technical Coordinator will approach partners and stakeholders to determine how many copies they want to distribute and support for printing.

Layout and Development:
• Agency will proofread provided copy and develop the layout using ISA-owned or free stock images.
• Layout will be provided to ISA and panels for final review prior to printing. Following final client approval, agency will publish and print the guidebooks and ship to ISA, Illinois Wheat and others as directed by ISA.
• Agency will also develop PDF, flipbook and eBook versions for posting to and and Illinois Wheat Association websites.
• Funds will be solicited from stakeholders to cover printing and distribution. Agency will collect the funds, organize printing and shipping back to partners.

Activity 3: Impact of wheat straw on soybean cyst nematode population and reproduction rates in the double crop wheat soybean rotation.
This project begins to assess the impact of wheat straw on SCN populations. The 4-month budget covers costs for completing the 2018 crop year from September 1 to December 31, 2018.

Soybean cyst nematode (SCN) remains the No. 1 production constraint to soybeans, but effective control options are limited. Wheat stubble left on the soil surface has been shown to reduce SCN populations and reproduction. The purpose of this study is to determine if no-tilling soybeans into wheat stubble will significantly reduce SCN populations in the soil even when soybeans have been planted.

Specific activity objectives: Determine if wheat stubble reduces SCN population and reproduction in fields planted back to soybeans immediately after wheat harvest in the same season.

A single 3-year doctoral research project conducted in Kentucky in the 1990s showed that wheat straw left on the soil surface reduced SCN populations (cyst and eggs) in the subsequent soybean crop. Removing the straw or tilling it in the soil negated the effect. The citation for this research is Hershman, D.E., an Bachi, P.R. 1995. Effect of wheat residue and tillage on Heterodera glycines and yield of double crop soybean in Kentucky. Plant Dis. 79:631-633.

This research hasn’t been repeated or validated elsewhere. Considering that SCN causes the largest yield loss to soybeans and that PI 88788’s source of genetic resistance is less effective leaves growers with fewer tools to control this threat. Adding wheat to the rotation before soybeans may be an additional tool to keep SCN populations under control and at a non-threatening level in the soil.

Production protocol: Cooperators will follow their standard production practices for wheat and soybeans including top dressing, weed control and spraying fungicides. However, after wheat is emerged, three strips of wheat will be terminated with herbicide for a "no wheat" effect in the rotation. Wheat will be terminated, and a residual herbicide applied at planting and a post herbicide will be applied in the spring to make sure winter annuals are not an alternate host for SCN. Soybeans will be no-tilled into wheat residue. Residue can't be baled off or tilled into the soil.

Field selection:
• Up to 30 potential double crop fields will be surveyed (sampled for SCN egg counts) in early September. These fields will be planted to wheat followed by soybeans next June.
• The field areas sampled should be recorded for follow-up sampling, especially for item 4 (below).
• Fields in the project should have a minimum of 500 eggs/100 cc soil and a range is preferred.
• Ideally, we would have 10 locations with a range of low (~500 eggs), moderate (1,000 – 2,500 eggs) and high (> 3,000 eggs) levels of SCN infestation.
• Fields can either be planted to corn or soybeans in 2018 followed by wheat and then double crop soybeans. If possible, it would be good to have a mix of fields that were in corn and soybeans.
• Nine growers will be selected for the study; 3 will low egg counts, 3 with moderate egg counts and 3 with high egg counts.

Experimental design/field layout:
• Need a minimum of two treatment comparisons at each location: Wheat vs. no-wheat strips (2 treatments) and three replications
• Need to mark similar sized strips in the adjacent wheat to serve as the “wheat strips” and non-wheat strips” for data collection/comparison. Strips should be similar in size and at least the width of the combine header.
• When fields are planted, the producer can drill the whole field. Later, after emergence, the wheat in the non-wheat strips will be terminated with herbicides. The producer can apply fertilizer and herbicide next spring across the whole field including strips without wheat.
• The wheat and no wheat strips must be at least 600-feet long and width should match up with combine header width and be a multiple of 15’ to match spray width.
• Each strip will be subdivided into three zones 200’ long to serve as subplots.
• Wheat and non-wheat strips will be managed identically.
• Producers will plant soybeans along the axis of the strip using their standard management practices and the dimensions and GPS location of the wheat and non-wheat strips will be maintained.
• Record the name of the wheat and soybean cultivars used, fertilizer, herbicide, fungicide, dates and rates, dates of planting and harvest of both the wheat and soybean.

Sub-zone sampling: The blue points will serve as the 7-inch cores (qty. 12) for the SCN counts in each subplot. The red point will serve as the centroid point to be marked with GPS and all collected data will be tied to these Lat./Long. coordinates. This red point will also be the sample location per subplot for soil fertility samples, if needed.

• Screen up to 30 fields in September 2018 and select 9 fields for the study.
• After wheat is planted and non-wheat strips located, strips are sampled in November 2018
• Wheat harvest in June 2019
• Mid-season for soybeans in late July/early August 2019
• After soybean harvest in late October or early November 2019; extracting and counting SCN
• Soil samples, consisting of 10 to 12 soil cores 15.24 cm (about 6 inches) deep from each subplot will collected at planting of wheat and soybean and at the midseason and harvest of the soybean crop. These sampling intervals are needed to assess impact of wheat production on soybean cyst nematode (SCN) population densities.
• Cysts, egg masses, and juveniles will be extracted from a 100-cc subsample by wet sieving using nested 850, 250, and 38 µm-pore sieves (Cobb, 1918). Cysts collected on the 250-µm-pore sieve will be ruptured (Faghihi and Ferris, 2000) and the eggs counted with the aid of a stereomicroscope. Soybean cyst nematode juveniles and other nematode species retained on the 38 µm-pore sieves will removed from debris with a centrifugal flotation technique (Jenkins, 1964). The nematodes collected at this step will be identified and the juveniles counted.

References for the technique:
Cobb, N.A. 1918. Estimating the nema population of soil. U.S. Department of Agriculture, Bureau of Plant Industries. Agricultural Technology Circular. No. 1. Washington. DC.
Faghihi, J. and J.M. Ferris. 2000. An efficient new device to release eggs from Heterodera glycines. Journal of Nematology 32:411-413.
Jenkins, W.R. 1964. A rapid centrifugal-flotation technique for separating nematodes from soil. Plant Disease Reporter 45:695.

Data to be collected in the wheat and no-wheat strips:
• Background SCN count during the initial field survey
• SCN eggs counts after wheat has emerged (this would be the time that the wheat strips and no-wheat strips are marked for data collection in 2017 and 2018)
• SCN egg counts at soybean planting, at mid-season, at soybean harvest
• Soybean yield collected with a yield monitor

Activity 4: Improving double crop soybean yield by planting earlier and staging proper maturity group.
This budget request covers the last four months of the 2018 crop year, from September 1 to December 31, 2018.

Double cropping soybeans after wheat is a popular rotation in the Southern third of Illinois and can move further North with the right combination of wheat and soybean maturity and harvesting dates. However, yield is usually limited due to late planting into poor soil conditions with limited investment or management. Planting double crop soybeans earlier can increase yield as much as 1 bushel per acre per day and significantly improve profitability. This project compares planting soybeans after early maturity/high moisture harvest with a later maturity/conventional harvest date with the right soybean maturity group.

Specific activity objectives:
• Showcase that planting earlier maturity wheat varieties and harvesting at high moisture allows double cropped soybeans to be planted 7 to 15 days sooner with a gain of 7 to 15 bushels per acre.
• Demonstrate that the wheat soybean double crop system can move further North in Illinois with the right combination of wheat and soybean varieties and wheat harvest moisture.
• Demonstrate that the earlier wheat varieties can yield like conventional maturity varieties while producing a higher quality wheat.

This project investigates that harvesting wheat earlier than normal means soybeans can be planted sooner into better soil conditions and with more opportunity for rainfall producing a better stand and larger plants that produce higher yield and greater profitability. And by adopting the early wheat harvest system along with shortening soybean maturity, the double crop rotation can effectively move further North in Illinois. And lastly, the early wheat harvest system will produce an equivalent yield to conventional wheat harvest systems but higher quality grain with greater test weight and lower DON (mycotoxin) readings, thus reducing dockage and improving price.

This is a joint project is to be funded by the wheat industry and soybean checkoff. Five wheat seed companies, Illinois Wheat Association and National Wheat Foundation have agreed to support the cost of managing the wheat plots and contributing seed. These same companies have also agreed to contribute soybean seed. However, cost of managing the soybean plots and analyzing data will be covered by soybean checkoff.

Four sites and contract researchers have been chosen to implement this project in Marion, Effingham, Wyoming and Walnut, Illinois. The field work will be near the contract researcher due to differential harvesting of wheat, planting of soybeans, harvesting of soybeans and taking notes. And PAQ Interactive we be responsible for compiling and analyzing all the data.

One field tour will be held at each site in July 2018. Tours will last 90 minutes and be followed by a light meal.

Progress of Work

Final Project Results

Updated January 9, 2020:

View uploaded report PDF file

View uploaded report 2 PDF file

EOY Final Report – Double-Crop Rotation

• Designed and produced a 31-page Double-Crop Production Guide highlighting the advantages and best management practices of double-crop rotation
• Programmed Guide to be available for online digital download via
• Developed CRM capture gateway to collect information for the benefit of the Illinois Soybean Association in exchange for a digital download of the Double-Crop Guide

• Increased understanding of best management practices and profitability for double-crop wheat and soybeans
• Increased recognition of ISA as a trusted leader in helping farmers be more profitable in the double-crop soybean wheat system

Constraint(s) on meeting the project objectives:
• Lack of best management practices is limiting field yield potential.
• It took extra time and effort to manage multiple members of the advisory board, collect feedback, and remind them of copy deadlines to keep the project on schedule.
• This led to additional and unplanned rounds of edits from the ISA contractor which stretched the budget and challenged our deadline timeframe.

Results and examples of changes the project brought about:
• Guide was released at the end of August; yield results of double crop system should be measured 1 and 3 years after release
• Download page via has been viewed 28 times since publishing in mid-August

Project Performance Measures:
• Created project timeline and general workflow process to keep contractors on time
• Collaborated with other contractors to determine content approach and general guide layout
• Established guide layout that achieved goals of project
• Coordinated proofing and editing process of guide
• Finalized project and distributed for digital download and CRM capture

Benefit to Soybean Farmers

Constraint: Lack of best management practices is limiting field yield potential.
Opportunity: Best management practices and new technologies can increase yield.

Performance Metrics

Illinois Producers
Illinois Certified Crop Advisors (CCAs)
Soybean and wheat industry seed providers and wheat millers

Develop an Illinois Double Crop Production Guide
Develop an Double Crop insert for Illinois Field & Bean
Demonstrate how wheat residue reduces SCN population
Determine how planting double crop soybean early improves yield and by how much per day
Suggest what soybean variety maturity group category works best in the in the double crop rotation
Surveying the status of SCN populations in the state of Illinois
Describing the status of SCN population levels farmers are facing today
Deliver results and messaging through communications, meetings and presentations
Prepare quarterly and final reports

Improve double crop management knowledge amongst Illinois producers
Develop a BMP for planting soybeans after wheat to suppress SCN reproduction
Develop a BMP for planting soybeans after the early wheat system to improve yield and profitability
Double crop system will be planted further north in Illinois
More farmers realize benefits of wheat in rotation with soybeans on yield and soil and water quality
Reenergize awareness of SCN and improve yields by promoting effective best management practices
Growers encouraged to evaluate SCN in their fields and implement better practices
Reduce the impact of SCN on yield and profitability

Project Years