Food for Thought

In two months both your physical and mental activities will turn to focusing on planting your 2018 soybean crop, so now is the time to ensure your operation is maximizing its opportunities. Diligent preparation is needed so you don’t allow a lack of fertility and an improper pH to hinder your success before the first seed ever goes in the ground. Additionally, it is no secret that corn may not be the “king” of the castle anymore and relying on its unused fertility leftovers is no longer a sound management decision.

Soybean fertility management must be a forethought and not an afterthought, to ensure that the basic building blocks are accessible to maximize success. Interestingly, modern soybean cultivars have a better response rate to improved management practices than older soybean cultivars. And from a management perspective, soil fertility is certainly one of the easiest practices to implement. Current, accurate soil test results from a reputable lab for each of your farms/fields is undeniably a critical first step.

Pushing yields to the next level will require you to treat soybean acres with the same rigorous fertility planning as your corn crop. Many times, that means putting a focus on fertility management practices. Below are several nutritional facts that may spark your interest and help increase soybean yields to those new heights when combined with recent genetic gains, improved weed control techniques, machinery advances and other progressive management practices.

Soybean nitrogen (N) needs are greatly influenced by the symbiotic relationship with brady rhizobium soil bacteria. Typically, N-fixation increases as soil levels of N decrease, if there are adequate rhizobia populations in the soil profile. A simple way to insure populations are satisfactory is to utilize inoculants, which are a relatively inexpensive addition to a program. This is especially true when planting earlier into cooler environments and certainly where soybeans have not been planted in the rotation the last several years.

While soybeans may potentially fix most of their own N under the right conditions, studies have shown that N from adequate soybean nodulation can only realistically provide acceptable N to support 60 – 70 bu yield levels. For higher yield situations the balance must come from residual soil N, if it is available. The late season addition of N is a subject that has certainly been talked about in recent years and is worthy of exploring as more data is provided.

Improved phosphorus (P) fertility is probably one of the most often disregarded factors that can aid in improving soybean yields. A yield environment able to produce 70 – 80 bu/A requires as much or more P than would be needed for a 230 bu/A corn crop, because soybean grain has a greater demand for P than corn. Additionally, banded placement increases availability and could improve early season growth rates when placed appropriately. Also, recent studies have indicated that annual applications of P when soil test levels are low can aid in early plant health optimization, increasing yields and reducing offsite nutrient movement.

Potassium (K), is removed in large quantities by a soybean crop at a rate of approximately 1.4 lbs. of K₂O per bushel, is needed for numerous plant functions. These include plant/water relationship management, stomata function, carbohydrate partitioning, and other nutrient allocation systems within the plant, all of which contribute to vigorous vegetative growth enabling increased pod and seed set. In fact, a lack of K reduces the plants ability to make and store energy via the photosynthetic process, impacting yield. Maximum K uptake occurs at R3 – R4 and approximately 62 percent of the K uptake is partitioned to the seed. Insuring that adequate K levels are present is paramount for increasing bean yields.

Paying attention to soil fertility is an undeniably immeasurable first best step to producing higher yielding soybeans.

Providing agronomic support and education to sales staff across all crops and geographies in the Dairyland Seed® footprint, Moran also has specific duties for managing Dairyland’s soybean portfolio. Joining Dairyland in June of 2004, serving as a District Sales Manager in Central/Southern IL and transitioning into his current role as Product Agronomy Specialist in 2010. Previously, he worked within the GROWMARK™ system for 16 years in various roles and locations.  Professional agricultural accreditations include his CCA in 2001 and CPAg in 2012.  He also proudly served as a Combat Engineer assigned to FORSCOM in the United States Army. He holds undergraduate degrees in Earth Science and Agronomy, as well as an M.S. in Crop Sciences from the University of Illinois, Urbana-Champaign.