Time for early season stand assessments

May 19, 2020 8:04 PM
Blog Post

Planting is nearly wrapped up for corn, with soybean soon to follow. What a difference a year makes considering the last two years have seen planting delayed. That means corn and soybean emergence should be good, right? Wrong! The cost of seed makes it essential to get the highest, most uniform emergence possible.

In general, this spring has led to good planting conditions, but there have also been some reasons for worry depending on when the crop was planted. The early planted corn and soybean may have had to struggle through two periods of cool, wet conditions which increased the risk of pathogen infection and cold injury. Some got planted into dry conditions and may have had limited moisture for germination. Additionally, thought should go into evaluating how the actual planter performed indicating adequacy of planter setup and maintenance.

The 5 ‘W’s of conducting stand assessments:

Who: Farmers, agronomists, and consultants should all be conducting early season stand assessments.

What: Stand assessments are a visual assessment of plants in a given area or field and include estimating of plant density (stand counts), assessing emergence uniformity, and observing seedling vigor as well as investigating reasons for poor stand assessments. Stand assessments can also identify seeding depth, sidewall compaction and root growth.

When: The easiest time to conduct stand assessments is at the 1st to 3rd corn leaf stage (V1 to V3) and 1st to 3rd trifoliate (V1 to V3) for soybean, however, conducting stand assessments at the time of emergence can help further sort out biotic issues from planter and operator performance.

Where: Conducting stand assessments should occur on every field but especially fields were there are obvious concerns. Make assessments in both the good areas and the bad areas of the field using an approach of one stand assessment for every 10 acres.

Why: There are 5 reasons for conducting stand assessments that can be used to improve stand establishment the next growing season. (1) assessing planter performance such as too much or little down pressure or worn planter parts; (2) assessing operator performance such as driving too slow or fast or improper setup for planter settings; (3) evaluating soil condition at and following planting such as too cold, wet, or dry; (4) identifying biotic issues such as insect feeding and seed/seedling diseases; and (5) predicting crop performance and additional issues going into the growing season.


For more information on conducting stand assessments visit:

Stand Assessments - Corn

Corn Growth Stages

Stand Assessments - Soybean

Soybean Growth Stages


Additional resources:

Stand Assessments (video)


Mark Licht Associate Professor

Dr. Mark Licht is an associate professor and extension cropping systems specialist with Iowa State University Extension and Outreach. His extension, research and teaching program is focused on how to holistically manage Iowa cropping systems to achieve productivity, profitability and en...