Jarrod O. Miller, Extension Agronomist, jarrod@udel.edu
In 2021 soils warmed up in mid-April and stayed there (blue line, Figure 1), overall remaining warmer than 2020 (green line), which lead to good field conditions for corn planting (Figure 1). This week we saw some air temperatures in the 80s, which lead to a fast rise in soil temperatures (yellow line). With rain and night-time temperatures in the high 40s this weekend, we will likely see a drop in soil temperatures, slowing any corn germination if you have taken this window to plant. Monitor those fields for any emergence (about 8-10 days from mid-April plantings) in case you must make replant decisions. By the 1st of May we should expect soil temperatures to remain above 50°F with emergence beginning to occur within 5-7 days.
Our soil moisture has been a little higher than 2020 and 2021 (Figure 2) due to recent rains, but as you can see it will be quickly depleted as soils warm up, evaporation occurs, and there is any lack of rainfall. Still, we don’t expect an issue with soil moisture without rain until later in May. At our research station in Sussex County, we plan on planting our first corn sometime next week (April 20-22).
Keep up with your regional conditions through DEOS (http://www.deos.udel.edu/).
Figure 1. Soil temperatures from mid-April to mid-May 2020-2022 in central DE.
Figure 2. Soil moisture from mid-April to mid-May 2020-2022 in central DE.