Some of the toughest early season barriers for soybean plants often come up during stand counts and uniformity checks. These road blocks, coupled with the unpredictability of Mother Nature, call for extra precautions at the onset of the season.
Inaccurate planter adjustments, soil crusting and soil moisture extremes, weather patterns, and pest/disease threats are just a few examples of what can cause poor uniformity in soybean fields. To get ahead of these early season concerns, make sure to account for the growth and development of soybean seedlings:
- Watch for reductions in variety stands: Plant stand reductions typically are patchy in distribution across a given field. Examples of non-uniform stand reductions may include: drowned-out areas; sandy, well drained areas with inadequate amounts of soil moisture; high traffic-compacted soils; or pest-infested areas.
- Gaps less than 2 feet in diameter will be compensated by adjacent/surrounding soybean plants.
- Gaps greater than 2 feet in diameter usually contribute to reduced yields.
- Be aware of frost injury: According to the University of Minnesota Extension, if temperatures drop to the low 30 or upper 20 degrees overnight, some degree of frost injury to emerged soybeans is likely to occur. Check plants 3 to 5 days after the event to allow for potential signs of new growth. Soybean plants should have firm, healthy stems, cotyledons and growing points. Replanting might be necessary, if cold conditions damaged the plants.
Following are tables to help calculate soybean stand. Table 1 represents the number of plants per foot of row for various row widths. (Take multiple samples of 1-foot stand counts). Table 2 provides stand counts based on drilled rows using the “hula hoop” or square yard measurement methods.
Your Golden Harvest Seed Advisor™ can help you decide if you should keep or replant your soybean varieties after evaluating the following:
- The cause of stand loss
- Stand assessment
- Uniformity
- Gaps
- Remaining stand
- Yield potential of remaining stand, keeping in mind:
- Original and new re-planting date
- University data suggests keeping the crop if existing stand is between 73,000-90,000 plants per acre, uniform and was planted in early June or later
- Jabbing in soybean seed to fill-in the stand is not recommended
Contact your Golden Harvest Seed Advisor with questions or for additional agronomic insights.
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