Soil Temperature Trends Important to Germination

ISUSM Station: Tewell Timeseries Soil Temperature at Depth Graph

Ideal stand establishment starts with placing the right seed into a well-prepared seedbed. The soil temperature in the seed zone is of critical importance to maximizing stand establishment. Soil temperatures at four inches deep do not always increase steadily with time. Germinating and developing seedlings may experience potential chilling injuries. Monitoring short-term forecasts may help growers find the best weather windows to avoid temperature stress.

Developing corn seedlings require soil temperatures above 50° F to progress. The results from research in the northern corn belt highlight the detrimental effects of persistently cool soils on final stands. A 3- to 4-day warm period following corn planting can help alleviate the potential for imbibitional chilling. Seedling injury risks decline significantly if the seed has those few days of warmer conditions as it initiates the germination process.  

The graphic shows daily soil temperature variability at Newell, Iowa at four-inch soil depths (Iowa State University Mesonet (IEM). Research results prove the detrimental effects that persistently cool soils have on germination and stand establishment, factors that influence final stands and yield potential.

For more, click here.