Soybean growers need to be careful about how deep they plant their seeds this growing season because, if not, they may see delayed emergence or even decreased yields. Michigan State University (MSU) researchers say that generally, soybeans should be planted at shallower depths, between 1 and 1.5 inches deep, under the following conditions:
- Early planting
- High-residue conditions
- Fine-textured soils
- Moist soils
Researchers say farmers should plant deeper, closer to 2 inches, in sandy soils as well as under these conditions:
- Late planting
- Coarse-textured soils
- Dry soils
Keep in mind that in order for a soybean to germinate, it must take in 50 percent of its weight in moisture. Planters typically provide better depth control than drills or air seeders. However, drills and air seeders can be improved when switched to narrow-profile gauge wheels.
Research conducted at MSU found that seeds planted 1.5 inches deep yielded 1.6 bushels per acre more than seeds planted 1 inch deep. As a rule of thumb, it is recommended to plant soybeans in at least 0.5 inch of moist soil.