How Benedict T. Palen, Jr. Plans Soybean Planting Date and Seeding Rate

 Two decisions made before a soybean crop emerges, when to plant and how many seeds to put down, set a ceiling on yield that nothing later in the season can lift. Benedict T. Palen, Jr., a fifth-generation farmer and agricultural consultant based in Denver, Colorado, treats them as a single plan rather than two separate choices. His approach is to set a planting window, work out the seeding rate needed to reach a target stand, and decide in advance what to do if the weather forces a change.

Start With the Date Yield Starts to Slip

University research gives growers a clear signal for when delay becomes expensive. Iowa State University reports that yield begins declining daily starting around April 25 in central and southern Iowa and May 1 in northern Iowa, and that growers should aim to finish planting within one to two weeks of those dates. Losses accelerate after mid-May. A multistate study led by the University of Wisconsin puts the loss at 0.2 to 0.5 bushels per acre per day after April 25 and estimates that mid-to-late April plantings often yield 5 to 10 bushels more than mid-May plantings. Nebraska research cites about half a bushel per acre per day after May 1. A 2024 Iowa trial found that moving from late April to mid-May cost another 2.3 bushels per acre, and planting on June 10 lost 11.8 bushels compared with April 5. He treats mid-May as a deadline.

Balance Early Planting Against Frost and Stand Risk

Earlier is not always better. April planting accepts frost risk, and one Iowa grower reported losing about half his plants in a frost year and interseeding at roughly 80,000 seeds per acre. Michigan State University, in a cooler climate, considers the first two weeks of May ideal for the lower half of the state and reports losses of about 0.6 bushels per acre per day after May 15. He tells clients to follow local extension guidance and the forecast rather than a date from another region.

Set the Target Stand, Not the Seeding Rate

The most common mistake in seeding rate is starting with the seed count. Iowa State research since 2004 shows a uniform stand of roughly 100,000 plants per acre at harvest is enough to maximize yield and profit, regardless of row spacing, and that higher populations reduce yield per plant without raising yield per acre. Falling short is costly: Golden Harvest trials suggest about a 2 percent loss in yield potential for every 10,000 plants below 100,000. He starts with that target and works backward.

Convert the Target Into Seeds

Not every seed becomes a plant. Iowa State notes that seeding rates of 125,000 to 140,000 seeds per acre with a planter were often enough to get a final stand of about 100,000 at harvest in a good seedbed with good seed. How many are needed depends on the planter, planting speed, seed quality, depth, weeds, and seedling disease. He asks growers to check emergence in a few spots a few weeks after planting and take stand counts before harvest.

Adjust the Rate With Planting Date

Date and rate interact. Beck's Practical Farm Research found that soybeans planted between April 16 and May 15 at a 100,000 seed rate averaged about $146 per acre more revenue than those planted between May 16 and June 15 at 125,000 seeds. Extra seed did not make up for the later date, and Iowa's 2024 trial similarly found that delay hurt more than fewer plants. Nebraska on-farm research found rates could drop to 120,000 seeds in some conditions without significantly affecting yield, so he asks growers to compare seed cost with their own stand results.

Record and Review

He asks clients to write down planting date, soil conditions, seeding rate, emergence counts, and final stand in one place. After a season or two, those records show how much of the seed placed actually became a plant, and whether the date or the rate is worth changing.

Conclusion

Planning soybean planting date and seeding rate comes down to setting a window around the date yield starts to slip, targeting a stand near 100,000 plants per acre, converting that target into a realistic seed count, and checking the result. With guidance from experienced consultants like Benedict T. Palen, Jr., growers can replace habit with a plan that protects yield and avoids paying for seed they don't need.