Update from the Field: Back to Bean Basics
Posted by David Dyson, Agronomist on March 05, 2018
This post may reference products and/or services only available to our Retail Farm Center customers. For more information contact your Territory Manager at The Andersons.
As my travels take me around the Midwest, I hear more and more farmers deciding to plant soybeans after soybeans. The USDA estimates soybean acres will be higher than corn acres in 2018. The majority of additional soybean acres will be coming from wheat or CRP ground, but there will be some acres of soybeans following soybeans. If you have growers that are considering growing continuous soybeans for the second or third year in 2018, there are several management decisions they need to be made aware of.
First and most important, soybean cyst nematodes (SCN). Hopefully, everyone read my article last fall, “How to clear up your SDS”, took my advice, and sampled their suspected SCN fields. If you did, you are way ahead of the curve. If not, no worries, we need to assume every soybean-after-soybean field has soybean cyst nematodes. Soybean cyst nematode is often referred to as a “silent yield thief” because SCN generally does not cause obvious symptoms on modern varieties, and soybean yields can be reduced by as much as 30%, according to Dr. John Grove at Spindletop Research Farm in Lexington, KY without visual symptoms. Most SCN-resistant soybean varieties rely on a single source of resistance, known as the “PI 88788” source of resistance, and unfortunately, there are SCN races that can reproduce fairly well on varieties that utilize this source of resistance. The best defense to SCN is a good offense. There are seed treatments that will prevent nematodes from attacking the soybean root system. Contact your local Ag Advisor from The Andersons to see what is available in your area (Figure 1).
Figure 1: Different seed treatment for SCN
Secondly, we have to ensure the fields maintain a pH between 6-7 and a calcium base saturation level between 60-70%. The days of going out and throwing two tons of ag lime on every acre are over. The Andersons’ GPS sampling program and VRT application equipment, available at our Retail Farm Center locations, can pinpoint low pH areas and apply product to only those areas, reducing the chance of “hot spots” occurring. If we have fields that are rented or need immediate help, NutraLime® DG is a good alternative. NutraLime DG can be applied with phosphorus/potash fertilizer, cutting out another pass in the field. This product will be readily available this growing year, unlike ag lime, which can take up to four years to breakdown in the soil.
Lastly, ensuring adequate potassium fertility is also a key component to a profitable continuous soybean production system. According to Purdue University, the potassium removal rate on an 80 bushel soybean crop is 186 pounds of potash (Figure 2). A grower has to apply 186 pounds of 0-0-60 just to keep their levels the same. Korrect™ is a highly-available, mild form of potassium which is particularly well suited for foliar feeding soybeans. Since the pH is 7.3 and the salt index is 26, there is little danger of burn to plant leaves. Korrect is a clear, true solution with no particulate matter, which mixes readily in water. The natural organic carrier enhances its receptivity by plants. This product contains no chlorides or ammonium (NH4) forms of nitrogen. To ensure maximum yields in a continuous soybean rotation, it is very important to ensure adequate fertility, particularly potash.
Figure 2: Nutrient removal rates from Purdue University
In conclusion, a continuous soybean rotation is not advised, but can be accomplished with a few tweaks with the overall program.
FOR MORE INFORMATION:
Please complete the form, and we’ll get you in touch with your Territory Manager from The Andersons.
Dave Dyson is a regional agronomist for The Andersons’ Farm Centers which are located throughout Ohio, Michigan, and Indiana. He is an Indiana native and grew up on a dairy farm in Miami County. A graduate of Purdue University with a degree in Crop & Soil Science, Dave has a deep knowledge of various agronomic topics and is committed to helping growers improve their crops. If you have any questions, Dave can be reached at david_dyson@andersonsinc.com.
NutraLime is a registered trademark of The Andersons, Inc. Korrect is a trademark of The Andersons, Inc.
