• Establishing healthy, uniform stands is important to maximize soybean profitability, even though soybeans respond to reduced stands better than many other crops.
  • Increased lateral branching can compensate for lower stands that are still relatively uniform (such as stand shown below), but only partially for gaps.

• Each year, DuPont Pioneer conducts a grower survey that documents soybean seeding rates used by customers on their soybean acres. 2014 results are shown below:

The primary factors affecting soybean seeding rate in Ill., Ind., and eastern Mo. are listed below. Agronomists suggest increasing seeding rates by 5% to 10% for factors that reduce stand.

• Planter or drill. Planters have traditionally done a better job of seed singulation and placement, increasing plant counts and stand uniformity. Growers using drills may need higher seeding rates to establish equally productive stands.
• Planting date. Early planting usually means colder, wetter soils, slower emergence, and reduced stands. Soybeans planted very late, including double-crop beans, require higher rates because they are destined to be shorter and produce fewer pods per plant.
• Soybean variety / maturity group. Some varieties respond more to higher soybean rates than others. In addition, studies have shown that early soybean varieties require higher populations for top yields.

• Tillage / residue cover / seedbed condition. No-till systems provide a less hospitable environment for soybean emergence due to colder soils, more residue, and possible seed placement / soil contact challenges. Cloddy soils may also reduce seed-soil contact.
• Seedling disease risk. Some regions have higher seedling disease risk due to soil types, weather patterns, and pathogen race shifts. Higher seeding rates are needed to establish target stands in areas or fields with a history of higher disease risk.
• Seed treatment combination. Research shows that some seed treatments improve soybean stands by using additional active ingredients that combat seedling diseases. Your Pioneer sales professional can help you select the best seed treatments for your field.
• Soil type. Soils with high clay content are much more likely to crust and restrict soybean emergence, and also promote seedling diseases in wet springs.

• After deciding on a final stand target, the grower must account for non-germinating and non-emerging seeds to calculate his seeding rate, according to the following equation:

Example 1 - Targeting a Final Stand of 140,000 Plants/Acre

• In order to reduce gaps, maximize profitability and minimize replant risk, a grower planting a maturity group 2.5 soybean variety in 15-inch rows in a well-tilled seedbed in mid-May targets a final stand of 140,000 plants/acre.
  • The seed tag indicates that germination is 90%, and because he is planting under relatively good conditions, he estimates emergence at 95%. His seeding rate is calculated as:

    140,000 / (.90 x.95) = 140,000 / 0.855 = 164,000 seeds/acre

Example 2 - Targeting a Final Stand of 142,000 Plants/Acre

• A grower drilling a maturity group 3.0 soybean variety in 7.5-inch rows in a no-till field in late April targets a final stand of 142,000 plants/acre.
  • The seed tag shows that germination is 90%. Because he is planting early in a no-till system, he anticipates cool soils and potential seedling disease challenges. Consequently, he estimates % emergence at 80%. Thus, his seeding rate calculation is:

    142,000 / (.90 x.80) = 142,000 / 0.72 = 197,000 seeds/acre