In the next few weeks growers across Illinois will start planting their soybeans. Planting soybeans at the right time, right depth and under the right soil conditions gives growers the best opportunity to get their crop out of the ground quickly, establish a vigorous crop stand and have a jump-start on reaching their yield goal.

Soybean growers have already made their most important soybean decision: what variety and maturity group to plant. But there are other factors growers should consider before planting starts. Growers sometimes pay less attention to seeding soybeans than corn. Seed is cheaper, beans are less sensitive to spacing and growers often overseed and don’t worry much about seed or seedling loss.

Soil conditions – It is important to place the seed into the furrow when the soil conditions are right. That can’t be overstated. You have only one chance to establish the crop so planting when conditions are optimal is a critical decision. Mudding in seed and planting seed into soil that is less than fit means creating soil and sidewall compaction resulting in a poor stand. The right conditions exist when the soil is moist but crumbly. There is no risk of compaction and the planter can former(form????) and close the furrow.

Planting date – Soybean planting starts as early as mid-April and extends up to late May. When growers start planting largely depends on how the weather cooperates each spring – and every year is different. Corn planting starts first and when they start planting soybeans is determined by how soon they finish corn, and some growers start planting soybeans before corn planting is even finished. Early planting means the soybean plant will have more nodes, branches and potential pods to fill. Even a gain of one pod per plant is equivalent to 2 bushels more per acre.

Seeding depth – Soybeans should be planted 1.5 inches and maybe even deeper at 1.75 inches. Most drills aren’t capable of maintaining consistent seeding depth as conventional row planters can. Deeper placement means planting into more consistent moisture and temperature and with less risk of hair-pinning by placing the seed into a ball of trash. And with today’s better cold tolerance and vigorous seed characteristics and the addition of seed treatments, planting a bit deeper makes more sense.

Row spacing – Row spacing is a very personal decision based on the crops grown and equipment available. Many growers have opted to plant in 30-inch rows for both corn and soybeans and run larger planters and multiple planters. So there has been a move away from narrow rows to wider rows and just maybe yield gain from earlier planting offset by planting in 30-inch rows. Soybeans produce a yield advantage when planted in narrow rows down to 15 or 20 inches. But in some seasons and with proper variety and good growing conditions, 30-inch rows will sometimes yield as much as narrower rows.

Seeding rate – Plant population for soybeans vary from 140,000 to 160,000 seeds per acre when seeded in rows. There is a trend to reduce seeding rate when planted in rows since 100,000 plants at harvest will optimize yield. Like with row spacing, the actual planting rate becomes a personal decision because it is up to the grower’s management ability and soil conditions at planting to decide how many more seeds to plant to achieve 100,000 plants (bushels) at harvest. Currently it seems the industry is comfortable with planting 140,000 to 160,000 seeds. Yet some growers with exceptional management capabilities can drop that down to 120,000.

Growers across Illinois are in the fields. They still have time to take a mental check to determine if they are prepared to seed their varieties following the 4Rs –the right time, in the right soil conditions, right depth and at the right population.

Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at

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About the Author: Dan Davidson

Soybean agronomist Daniel Davidson, Ph.D., posts blogs on topics related to soybean agronomy. Feel free to contact him at or ring him at 402-649-5919.