In the past several years, growers are realizing potential for higher and higher soybean yields. While this can be correlated with improved modern genetics, growers’ implementation of better modern agronomic practices has been essential.
“To produce higher yields, it is all about bloom and pod retention,” says Todd Steinacher, AgriGold agronomist. “A soybean plant has been known to abort up to 70% of its blooms and/or pods in order to create an equilibrium the plant feels it can support.”
There are several factors that can play into successful pod fill, but AgriGold agronomists Ron Roling and Todd Steinacher have narrowed it down to three.
Abundant sunshine combined with plenty of soil moisture is the best recipe for a great soybean crop. When it comes to water usage, the soybean plants biggest need for water comes during the reproductive stages. In fact, Roling says that nearly 65% of the soybean crops total water usage for the entire year is used from beginning bloom (R1) to full green seed (R6). During peak usage the soybean plant can use .32 inches of water per day.
Steinacher points out that soybean plants can remobilize to support new pod growth after a less than ideal start if growing conditions improve. This can be seen in years where drought is prevalent, but then rain returns later in the season while soybeans are still in the R5 and R6 stages.
2. Fertility and pH
“We often focus on the macronutrients of N, P & K when it comes to crop fertility,” said Roling. “These nutrients are critical and should have our attention, but soybean plants require several other nutrients for grain fill.”
Micronutrients like Zinc, Boron, Magnesium, Iron, Copper and Sulfur can be very important at this time. Roling says that soil sampling ahead of planting along with in season tissue sampling are great ways to determine the micronutrient needs of a soybean crop.
One major factor for optimal soybean performance is pH. The optimal range for soybean pH is between 6.0-7.0. Having soil fertility and pH balanced will allow for better nutrient uptake and biological N-fixation throughout the entire season.
3. Keep Plants Healthy and Free from Stresses
Both agronomists agree on their recommendation to use a fungicide and insecticide to keep diseases and insects under control.
“Foliar fungicide not only fights disease, but also lengthens the seed filling period. By keeping leaves healthy and green longer the plant can increase seed weights,” said Roling.
Roling continued to explain that about 60% of soybean yields come from nodes 7 through 13, so protecting these later in the season becomes crucial to yield. Adding an insecticide to a fungicide pass will keep all defoliating and sucking pests under control, helping growers to keep the soybean plant “factory” running at its highest potential.
Being aware of stresses that the soybean plants are being put under and their influence on pod fill is an essential part of maximizing soybean yield potential.