CFAES Give Today
Agronomic Crops Network

Ohio State University Extension


Battle for the Belt: Episode 5

Battle for the belt

Episode 5 of Battle for the Belt is now available:

In Episode 5, learn about corn and soybean germination and emergence, imbibitional chilling, and cold injury… All are important considerations for early planting! Also, hear from an Allen County, Ohio farmer on what he plants first and why. Hint: He is Team Soybean.

Germination and emergence in corn and soybeans is affected by soil moisture and temperature. Seeds will imbibe water from the soil and swell and will then germinate with emergence of the radicle and shoot from the seed. The germinated seeds need to then navigate through the soil prior to emerging from the surface. In corn, we have seen that it takes 150 soil (temperatures tracked in the soil, not in the air)-accumulated growing degree days (GDDs) after planting to get 50% emergence, with 90% emergence occurring by 180 soil GDDs. This was consistent regardless of planting depth. We did see slightly earlier calendar day emergence when planting was shallower, but the window of emergence (10% to 90% emerged) was extended compared to deeper plantings. Damage to corn seedling caused by cold injury. (Photo courtesy of Mark Licht at Iowa State University. Used with permission.)If flooding occurs after planting prior to emergence, warmer temperatures (80°F) with the flooding are much more detrimental in corn than cooler temperatures (60°F) for periods longer than 48hr due to higher respiration rates and possibly lower dissolved oxygen levels. Soybean emergence will also be extended with cool temperatures and could slow early growth and development. This could lead to greater susceptibility to some pests (like slugs) early on and could slow canopy closure and affect early-season weed issues. Extended waterlogging durations could also increase issues with seedling blights and oomycete infection, though severity may also depend on temperatures.

Patience is needed when checking early planted fields for emergence as cooler days will accumulate GDDs slower, leading to emergence at later calendar dates than one may expect. When checking on seeds in-furrow prior to emergence, look for seeds to be swollen (from imbibition) and to be exhibiting active growth (radicle/roots, starting shoot development) because dead seeds can still imbibe water. Check for patterns in the field if uneven emergence or stand is observed to diagnose the cause (e.g., crusting, pest damage, sidewall compaction, planting depth). If concerns exist regarding low and variable stands on either crop, replanting can be a consideration; however, not necessarily the solution. Before deciding on replanting, be sure to assess the final stands and initial planting date to make that decision. Research in corn has shown that a lower stand of plants planted early may yield as good or better than a higher stand planted late (i.e., replant). Plus, soybeans tend to compensate better given their branching capacity.  

Keep following the ‘Battle for the Belt’ this growing season to learn more and get further updates! You can find the full video playlist of Battle for the Belt on the Ohio State Agronomy YouTube channel.


Fausey, N.R., and McDonald Jr., M.B. (1985). Emergence of inbred and hybrid corn following flooding. Agronomy Journal 77:51-56.

Nemergut, K.; Thomison, P.; Carter, P.; Lindsey, A. (2021). Planting depth affects corn emergence, growth and development, and yield. Agronomy Journal 113:3351-3360.

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.