As producers strive to increase soybean yields, research into many high yield strategies have shown promise.  One of those strategies is utilizing starter fertilizer applications, according to Nutra-Flo Company.

There has been a lot of discussion about fertilizing soybeans recently. Nutra-Flo officials contend that soybeans respond to starter applications differently than corn and can lead to inconsistent results if not managed properly.

“In two separate soybean specific research projects during the 2014 growing year the use of a starter fertilizer increased yields by more than 10 percent,” according to Brian Banks of Nutra-Flo.  “The most consistent results are attained when other high yield management strategies are used in conjunction with starter applications.”  These include planting date, population and the use of crop protection products such as insecticides and fungicides.

The type of nutrients to be applied is the first aspect to consider.  Both phosphorous and potassium will greatly influence soybeans, according to Banks. He outlined specifics related to nutrients impacting soybean yield. Phosphorous helps to stimulate early root growth and development, and potassium has been proven to enhance nodulation and increase nitrogen fixation in the nodules.  Potassium has also been shown to increase the size of the leaf and the total leaf area. Nitrogen is typically added to the formulation in small amounts to add in the uptake of other nutrients.  High levels of nitrogen in close proximity to the roots early in the season can have a detrimental effect on nodulation and fixation. The addition of micronutrients, such as manganese has also shown positive results when added to a starter application.

The combination of these plant nutrients in a starter application can benefit soybean yield potential in many ways, Nutra-Flow contends. Increased root mass helps in utilizing more nutrients and water present in the soil profile leading to more vigorous early season growth. This increase in root mass can also aid in the earlier establishment of nodulation. Greater early season growth, along with larger leaf area from potassium results in greater light interception. More light interception leads to an increase in photosynthesis and thus more carbohydrate production. Carbohydrates are the currency the soybean plant utilizes in its symbiotic relationship with rhizobia bacteria in the nodules in exchange for nitrogen. An increase in growth and leaf area also has the benefit of quicker canopy closure, helping in weed suppression and reducing evaporation from the soil surface.

Because of a starter fertilizer, Nutra-Flo explains that the soybean plant is functioning with the least amount of stress possible as it enters into the reproductive stages. The contention is that unlike corn, this part of the season is when soybean yield is determined. After flowering has occurred, the soybean plant will begin to decrease the amount of carbohydrate sent to the nodules and instead sends this energy source to the developing seed. 

As seed development progresses, nodulation begins to decrease and will eventually cease towards the end of the season. “To prevent a decrease in the established potential of the soybean crop from a starter application; in the form of pod abortion, a late season foliar application of nitrogen should be considered. Slow release nitrogen applications near the R3-R4 growth stage have been proven to reduce pod abortion and increase yields” said Banks.

Nutra-Flo is promoting the use of two specific products to boost soybean yields. The PureGrade RoMax Soybean Starter and Super 72 slow-release nitrogen are recommended for soybean production by company representatives. In conclusion, the company says through the use of high yield management strategies, including starter and foliar fertilizer applications, producers can greatly influence the yield potential and ultimately the profitability of soybean crop.