Soybean cyst nematode (SCN) is the most damaging pest in U.S. soybean production. It affects more than 200,000 growers, and annual soybean cyst nematode yield loss costs growers an estimated $1.5 billion. Despite the widespread impact of soybean cyst nematode, its symptoms are often subtle or go unnoticed until yield loss becomes severe.1
Early detection and effective soybean cyst nematode control require both thorough, informed scouting, soil testing, and proactive management, especially in high-risk fields. There are even tools available to help you track nematode pressure and detect infestations earlier in your area.
One of the most overlooked aspects of SCN management? Soil health. Healthy soils not only support more vigorous plants, they can also influence SCN pressure, particularly in relation to soil pH and structure.
Healthier soils equal healthier plants
SCN thrives on stressed soybeans, and the health of your soils plays a large role in that. Improving soil structure, boosting organic matter and supporting microbial life can give soybean roots a better chance to grow deep and resist damage. A strong root system is key to helping plants tolerate the presence of soybean cyst nematode and maintain yield.
If you’re considering cover crops to improve your soils, make sure to only plant cover crops that aren’t a host for SCN to break up the pest’s lifecycle. Cover crops that can host SCN include lupine, field pea and forage pea. Non-host options like alfalfa, annual ryegrass, hairy vetch, white clover and oats make for good cover crops after soybeans.2
While these practices won’t eliminate SCN populations entirely, they support soybean cyst nematode control by improving plant vigor and tolerance.
Soil pH impacts soybean cyst nematode levels
Soil pH can influence both SCN populations and how soybeans respond to them. Studies show that SCN tends to thrive in soils with a pH above 6.5. Slightly acidic to neutral soils (pH 6.0 to 6.5) are less favorable for SCN reproduction and can help reduce population growth over time.3
Amendments such as elemental sulfur, aluminum sulfate, iron sulfate and ammonium sulfate can all lower pH in soil to make your field less hospitable to soybean cyst nematode. Elemental sulfur specifically is a common amendment because it is relatively inexpensive, safe to use and available at most local agriculture suppliers.4
That said, adjusting pH should be done with care. You don’t want to create deficiencies in other essential nutrients. Soil testing is the best way to assess your soil’s pH and make informed decisions about lime or sulfur applications, if needed.
Is no-till or reduced tillage effective for soybean cyst nematode control?
Tillage practices have a complex relationship with soybean cyst nematode. In Minnesota, research shows that no-till or reduced tillage has limited impact on reducing SCN egg population density.5 In some cases, conventional tillage may actually improve early-season root development and reduce the visible damage caused by SCN.
However, it’s essential to note that no form of tillage, whether conventional or reduced, can consistently lower SCN numbers in the soil. To effectively manage SCN populations, tillage must be part of a broader strategy. This includes rotating with non-host crops, such as corn or wheat, and planting SCN-resistant soybean varieties.
SCN resistant soybean varieties are currently the most effective tool to manage soybean cyst nematodes.
While reduced tillage supports long-term soil health, which can help soybeans better tolerate soybean cyst nematode stress, SCN population control still depends on integrated management practices.
A new tool in the fight: Nemasphere
SCN resistant soybean varieties are considered the most effective tool to manage soybean cyst nematodes. Known for suppressing nematode reproduction, resistant varieties work by incorporating resistance genes that reduce SCN population densities over time, critically slowing the pest’s buildup in the soil. Unfortunately, SCN resistant traits are getting tired from overuse and losing effectiveness. Rotating between different resistance sources prolongs their effectiveness and delivers substantial economic benefits to farmers.
For growers looking to take the next step in SCN management, thankfully a new option is emerging: Nemasphere, the first EPA-registered transgenic trait for SCN control. Designed to complement existing practices like resistant varieties and crop rotation, Nemasphere targets SCN from within the plant itself, helping reduce nematode reproduction and protect yield potential.
When combined with good soil health practices and a strong crop management plan, Nemasphere offers a powerful new layer of defense against one of the most persistent threats to soybean production. You can learn more about how Nemasphere can help you fight against soybean cyst nematode by watching this video.
Experts are available to help you make your decisions. Reach out to your seed retailer, a nearby extension office agent or a seed company professional like your regional BASF representative.
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Endnotes
- “Soybean Cyst Nematode.” Integrated Crop Management Encyclopedia, Iowa State University Extension and Outreach, 20 Nov. 2014, crops.extension.iastate.edu/encyclopedia/soybean-cyst-nematode.
- Strunk, Connie. “Cover Crop Considerations When Dealing With Soybean Cyst Nematode.” SDSU Extension, South Dakota State University, 10 Feb. 2022, https://extension.sdstate.edu/cover-crop-considerations-when-dealing-soybean-cyst-nematode.
- Bissonnette, Kaitlyn, Travis Faske, and Albert Tenuta. “An Overview of Soybean Cyst Nematode.” Crop Protection Network, 23 April 2021, doi:10.31274/cpn-20210423-0, cropprotectionnetwork.org/publications/an-overview-of-soybean-cyst-nematode.
- Longstroth, Mark. Lowering the Soil pH with Sulfur. Michigan State University Extension, www.canr.msu.edu/uploads/files/Lowering_Soil_pH_with_Sulfur.pdf.
- Chen, Senyu, James Kurle, Dean Malvick, Bruce Potter, and James Orf. “Soybean Cyst Nematode Management Guide.” University of Minnesota Extension, 2021, extension.umn.edu/soybean-pest-management/soybean-cyst-nematode-management-guide.
