Summary: Three years of population studies have only shown little difference in population (60-180k), when planted early enough, however later planted  (double crop) beans may be safer at 120k or above. Planting in 15 inch rows can increase yields 5-10 bushels.

As soybean genetics have improved, national studies in planting populations are revealing that lower populations can still provide similar yields. We have performed studies over the past few years, including 2022 (Click for link) and 2023 (Click for link). For both of those years there was a 10-bushel advantage for narrower rows (15 vs 30”), 25 bushels for irrigation, but no differences between populations of 90 to 180,000 seeds per acre.

Soybean Row Spacing and Population Studies

Modern soybean varieties can tolerate lower seeding rates and still produce good yields, providing there are no other issues with stand loss or stress. In southern Delaware two studies (2022 and 2023) observed no yield difference when planting full season beans (MG 4.2, late May planting date) when planted between 60,000 to 180,000 seeds per acre (Figure 1). You may consider dropping your seeding rates, considering your regional weather, planting date, and soil conditions.