Soybean sudden death syndrome (SDS) is one of the most devastating fungal diseases affecting soybean growers. With no in-season treatment available, SDS is responsible for significant economic losses, costing growers more than 21 million bushels in 2023.¹
But here’s the good news: a recent Kansas State University study has discovered a new potential line of defense: phosphorus.
How can you use phosphorus to combat this early-season soybean killer? Keep reading to get an overview of how this game-changing discovery could help you protect your crop and score higher yields.
Importance of soybean phosphorus deficiency
Since nutrient deficiencies make soybeans more susceptible to sudden death syndrome, it’s no surprise that compensating with higher levels of vital nutrients can help reduce the prevalence of this disease.
Sufficient soybean phosphorus content promotes root development, helps increase energy transfer and improves photosynthesis. But soybean fields frequently suffer from low phosphorus levels, leaving plants in soybean phosphorus deficiency, which weakens plants and allows them to more easily fall victim to SDS.
New research reveals new tool for fighting sudden death syndrome
Over several years, Kansas State researchers looked at the impact of adding varying rates of phosphorus, nitrogen and potassium to fertilizer to attempt to combat SDS.
The research concluded that nitrogen and potassium alone did not combat SDS, but nitrogen and phosphorus seemed to reduce SDS and increase the crop’s yield. The more phosphorus added to fertilizer, the less SDS foliar disease in the soybean field.
The study tested adding fertilizer at three rates and determined the highest rate (60 lbs per acre) was most effective at reducing disease.²
Conditions that exacerbate soybean phosphorus deficiency
When preparing a field for soybean planting, pay attention to certain conditions that might indicate a greater likelihood of soybean phosphorus deficiency. Phosphorus deficiency is typically made worse by cold or wet soils, acidic or very alkaline soils, or soils with low organic matter.³
Additionally, iron-rich soils and high-phosphate capacity can exacerbate soybean phosphorus deficiency. High-phosphate capacity in soil means that the amount of phosphorus available to plants is reduced. Understanding your soil’s phosphate capacity will help you predict how much phosphorus must be applied to your field to achieve the optimal soybean phosphorus content.⁴
Thanks to the findings in the Kansas State research, phosphorus may be a welcome addition to your SDS-fighting toolbox. Experts are available to help you incorporate a phosphorus application protocol into your operation. Reach out to your seed retailer, a nearby extension office agent, or a company professional like your regional BASF representative.
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Endnotes
- “Soybean Disease Loss Estimates from the United States and Ontario, Canada — 2023.” Crop Protection Network, 14 Mar. 2024, cropprotectionnetwork.org/publications/soybean-disease-loss-estimates-from-the-united-states-and-ontario-canada-2023. Accessed 18 Nov. 2024.
- Melgares, Pat. “K-State: Phosphorus Helps Boost Defense Against SDS in Soybeans.” K-State Research and Extension, 28 June 24, www.ksre.k-state.edu/news-and-publications/news/stories/2024/06/agriculture-soybeans-sudden-death-syndrome.html. Accessed 18 Nov. 2024.
- “Phosphorus Deficiency-Soybean.” Yara United States, 4 Mar. 2020, www.yara.us/crop-nutrition/soybean/nutrient-deficiencies/phosphorus-deficiency-soybean/. Accessed 18 Nov. 2024.
- “Phosphorus - Soil Management.” University of Hawaiʻi at Mānoa, 2024, www.ctahr.hawaii.edu/mauisoil/c_nutrients02.aspx. Accessed 18 Nov. 2024.
