Growing soybeans requires more management today than 20 years ago due to earlier planting and increased disease and insect pressure. |
Soil type, tillage system, drainage, geographic location, expected rainfall, potential diseases, and other local factors must all be accounted for in choosing an appropriate variety.
Soybean yield response to planting date. Data from 23 site-years (IA, IL, IN, NE and MN), 2006-08. Pioneer Agronomy Sciences.
Average yield results from 7 soybean row spacing studies published during the last 10 years.
(Hanna et al., 2008; De Bruin and Pedersen, 2008; Kratchovil et al., 2004; Cox and Cherney, 2011; Janovicek et al., 2006; Bertram and Pedersen, 2004; Pedersen and Lauer, 2003.)
Seeding rate decisions should be based on soybean seed cost, grain market price and individual production practices and seedbed conditions.
Higher seeding rates may need to be maintained to help prevent potential yield reductions or replanting when seedbed conditions, weather or pests are likely to reduce stands.
Optimum economic seeding rates at soybean market prices of $10, $12, and $15/bu and a $60/unit seed cost based on Pioneer research conducted across 9 locations in IA, IL, IN, MN, and NE.
(Research trials were planted in 30-inch rows, economic optimumseeding rates would be expected to be greater in narrow rows.)
An 80 bu/acre soybean crop would remove about 64 lbs P2O5 and 112 lbs K2O from the soil in the grain. Soil testing can determine if field levels are adequate to supply these or other required amounts.
Soybean plants have high nitrogen (N) needs, which are usually supplied by N-fixing rhizobia bacteria associated with the roots.
Adding N fertilizer is usually unnecessary under normal production practices, However, research in some irrigated, high-yield environments has demonstrated that applications of N during the pod or seed stages of soybean development can increase yield.
Soybeans are more often deficient in manganese than in other micronutrients, and respond well to manganese fertilizers when deficient.
Soybean nutrient needs for an 80 bu/acre crop
Disease control begins with scouting to understand disease risks and their potential severity in each field. Variety selection, crop rotation, seed treatments and foliar fungicides are the best tools available to counter most disease threats.
Management of soybean aphid or bean leaf beetle may be necessary for top yields. Scout diligently and treat with an insecticide if needed.
Due to earlier planting and higher levels of crop residues, fungicide-insecticide seed treatments are becoming more common and merit testing by growers. Pioneer research has shown increased yields and profits with these products.
Strobilurin fungicides applied at the R3 growth stage have consistently increased soybean yields in Pioneer studies. Including an insecticide in the tank was usually cost-effective.
Yield response of soybean to Headline® and Asana® applied at the R3 growth stage in Pioneer research studies (2007-08).
Effective weed management in soybean has often been relatively easy to achieve in recent years due to the availability of glyphosate-resistant varieties; however, glyphosate- resistant weeds are becoming increasingly common.
Using a preemergence herbicide can improve weed control, and additional postemergence herbicides may be necessary to prevent escapes of weeds not controlled by glyphosate.
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Product responses are variable and subject to many factors including soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary.