The cool, wet spring has delayed soybean planting in Michigan. However, when field conditions are suitable, soybean planting will proceed rapidly. In order to get the crop off to a good start, Michigan State University Extension encourages producers to consider four factors when planting soybeans:
- Soil moisture
- Planting depth
- Seed-to-soil contact
- Planting equipment calibration
The soil and crop residue must be dry enough for the seed furrow opening and closing equipment to operate properly. However, there should be enough soil moisture available to place the seed into 0.5 inches of moist soil.
The optimum planting depth for soybean is between 1 to 1.5 inches. Planting at the shallow end of the range is recommended when planting into high residue conditions or into soils prone to crusting. Planting at the deeper end of the range is recommended when planting into dry soils or coarse-textured soils and when planting late. Check your planting depth whenever soil or residue conditions change.
Good seed-to-soil contact is essential to achieve uniform and rapid emergence. The seed should have good contact with the soil, but the soil above the seed should not be compacted by the closing wheels. Seed furrow compaction is more likely to occur when soils are on the wetter side. If seed furrow compaction is occurring, try reducing the down pressure on the closing wheels. If this doesn’t correct the problem, wait for the soil to dry. If the soils are on the dry side when planting, slightly more down pressure may improve seed-to-soil contact.
Periodically check to make sure that your planter or drill is planting the intended amount of seed.
Always recalibrate planting equipment when switching to a different variety as there is a wide range of seed sizes this spring. Special adjustments will be required if you are planting seed larger than 2,400 seeds per pound. Drills equipped with fluted metering systems can damage seed larger than 2,400 seeds per pound. Consider plugging every other feed cup on the drill and increasing the width of the feed cup opening when planting large seed. Another option is to increase the distance between the bottom of the feed cup and fluted metering mechanism if this adjustment is available.
The time you spend monitoring soil moisture, planting depth, seed-to-soil contact and planting equipment calibration will be rewarded with uniform and rapid soybean emergence.
This article was produced by the SMaRT project (Soybean Management and Research Technology). The SMaRT project was developed to help Michigan producers increase soybean yields and farm profitability. SMaRT is a partnership between MSU Extension and the Michigan Soybean Checkoff program.