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This is Dr. Nathan Mueller, your local agronomist with Nebraska Extension for Dodge and Washington counties. As your local extension agronomist, it is my job to help improve the profitability and sustainability of local cropping systems. We just finished up with the meetings for Nebraska On-Farm Research Results in Mead, Norfolk, Grand Island, Grant, and Alliance. One attendee at Mead told me that the one consistent result from on-farm research over the years was that lower soybean seeding rates were justified and I said that I totally agree.
Reduce soybean seeding rates and add profit. That is how I can best summarize the latest on-farm research results in eastern Nebraska done by farmers, in their fields, with their own equipment. You can find and view all the soybean seeding rate studies conducted by farmers at resultsfinder.unl.edu. Let’s review the results from 10 studies conducted from 2014 through 2017 that used similar seeding rates of 90K, 120K, 150K, and 180K/acre (figure below). These studies were conducted in Merrick, Lancaster, Seward, Saunders, and Washington counties with yields levels ranging from 60 to 96 bushels/acre. Averaged across the studies, a yield increase of 2 bushel per acre was measured by increasing the seeding rates from 90K to 120K, with no further yield increases above 120K seeds per acre. Looking at each individual study, 4 studies recorded the most profitable seeding rate was actually 90K. In only one of the ten studies was there an advantage from increasing the seeding rate from 120k to 150K. There was never a yield or economic benefit to increasing seeding rates above 150K seeds per acre. Again, check out the reports yourself at resultsfinder.unl.edu.
The current recommendation based on these on-farm research results is to plant 120,000 soybeans seeds per acre. Current recommendations from Iowa State University just to our east are similar at 125,000 to 140,000 seeds/acre. During my annual Dodge County Preharvest Yield Tour the first week of September, the average soybean plant population in 2015, 2016, and 2017 was 161K, 157K, and 118K plants per acre, which means seeding rates were much higher. Research data has concluded that 100,000 plants per acre as harvest is a great target.
Inherently you try to minimize the risk of a poor stand through using fungicide seed treatments, planting extra seed, and buying hail insurance. I believe that a fungicide treated seed planted at 170,000 seed/acre and purchasing hail insurance is too costly of a risk management plan. So purchase the hail insurance, use treated seed, but reduce you seeding rate down to at least 140,000 seeds/acre. Overall, many of you have an opportunity to reduce your soybean seeding rates, decrease seed cost, maintain yields, and increase profits.
To listen to this radio message again and to get more information, you can also visit our local website at croptechcafe.org or give me a call at 727-2775. Know your crop, know your tech, know your bottom line. This is Dr. Nathan Mueller, your local agronomist for Nebraska Extension on KTIC radio.