Jarrod Miller, Extension Agronomist, jarrod@udel.edu

The preferred soil temperature for corn germination is 50°F, which allows the seed to begin root and shoot growth. When soils fall below this temperature, germination may be limited and seeds may rot in the ground. This past week has seen increased air temperatures across Delaware, but soils take longer to warm up.

In the past few days, we have started to see consistent temperatures for corn planting. Since April 1, average daily soil temperatures ranged from 45-58°F in Newark, 46-60°F in Dover, and 48-63°F in Georgetown. This has mostly been a linear increase in temperature, with soil temperatures consistently above 50°F the last few days. Temperatures over the next week have highs in the 70s, with a few nights in the lower 50s, so our soil temperatures may hold for corn planting.

If you are interested in daily soil temperatures in your area, check the Delaware Environmental Observing System (DEOS) website: http://www.deos.udel.edu/data/agirrigation_retrieval.php.