Director of Research, Iowa Soybean Association

Producing high yielding soybeans takes teamwork. The right genetics, a blessing from Mother Nature and the right management decisions by you make a profitable and unbeatable team.  Although it’s difficult to predict what curves Mother Nature will throw at you, there are things you can do now to put the odds of bin-busting yields in your favor.

Growing soybeans requires more management today than 30 years ago due to earlier planting and increased disease and insect pressure. Early-season disease infections reduce stands and necessitate replanting and if severe enough can reduce yield. Disease incidence and severity are highest in fields with slow drainage or where periodic saturated soil conditions occur.

Fungicide seed treatments have been shown to reduce stand loss caused by seedling diseases but reports of increased yield have been inconsistent. The effectiveness of fungicide seed treatments is influenced by variety, planting date, soil moisture content, and timing of rainfall. Nevertheless, fungicide seed treatments are a cost effective management tool to avoid stand loss and potential yield loss from a replanted crop.

The prophylactic use of soil inoculants is increasing. Rising input costs, escalating land prices, and volatile commodity prices are all driving the need for soybean producers to improve profitability. However, the use of inoculants to increase yield may not be the solution farmers are looking for, especially if soybeans have been grown in the recent past.  In fact, the prophylactic use of inoculants without an active on-farm testing program could be costing you money. A recent report by several Midwest soybean specialists suggests that prophylactic use of inoculants is not a good management practice for profitable soybean production.  However, if a field has not produced soybeans in the past four or five years or has never produced soybeans, an inoculant is needed for nitrogen fixation to occur.

Planting practices, including row width, planting date and seeding rate may have a significant effect on yield. Recent multistate research suggests a final stand of 125,000 plants per acre may be the most economical. While the optimum planting date is state specific the benefit from planting in narrow rows is not.  Several research programs have shown that soybeans grown in 15 inch rows can produce higher yields than those grown in 30 inch.

Although soybean yields have increased more than 32 percent in the last 30 years those yield gains can quickly be lost to uncontrolled insects such as soybean aphid, spider mite, and bean leaf beetle.  Scout individual fields diligently, know and understand economic thresholds and treat with an insecticide only when necessary.

Control weeds. Weeds left uncontrolled for the first ten days after soybean emergence reduces yield.  The use of a pre-emergent herbicide in addition to a glyphosate application controls the early flush of weeds and is a good management practice to delay the buildup of glyphosate resistant weed populations.

Growing soybeans as a rotational crop is easy.  Growing soybeans profitably is more challenging. “Best Management Practices” are available to help you meet that challenge and more; the latest science based recommendations can be found at www.planthealth.info.  That’s your soybean checkoff. Delivering results.

-David Wright

-Funded through the Soybean Checkoff