Warmer winter soils may have an effect on agriculture and crop pest control this spring, according to researchers at the Prairie Research Institute at Illinois.
Statewide temperatures at depths of 4 inches under bare soil have averaged 36.3 F so far this winter, according to Jennie Atkins, the Water and Atmospheric Resources Monitoring program manager at the Illinois State Water Survey, a division of the institute. The temperature is 2.5 degrees above the long-term average, but 0.4 degrees lower than last winter. While there were periods in December and early January in which averages fell below freezing, soils have been warmer than normal for most of the season.
Soil temperatures have been higher than normal throughout the state. The highest temperatures have been reported in southern Illinois, with a seasonal average of 39.4 F, 2.6 degrees higher than normal. Northern Illinois had the lowest temperatures, with an average of 33.1 F, or 1.1 degrees above the long-term average.
Soils have been steadily warming since early February. On Feb. 21, soil temperatures averaged 52.9 F, 20.3 degrees warmer than the long-term average. Daily highs reached into the low 60s at several stations in central Illinois. Under sod, soil temperatures were higher than normal, averaging 38.4 F at 4 inches and 38.5 F at 8 inches this winter, 3.1 and 2.5 degrees higher than normal, respectively.
Kelly Estes, the state agricultural pest survey coordinator with the Illinois Natural History Survey, a division of the institute, addressed the topic of crop pest control at the recent University of Illinois Crop Management Conferences.
“Generally, milder winters do allow for greater survivorship of overwintering pests,” Estes said. “There are a few things to take into account, though. While some pests overwinter here, others will migrate.”
Of the ones that overwinter here, the previous year’s population will be a factor. If the pest population was low in 2016, it’s going to start low in 2017, she said.
“It’s also important to remember that favorable conditions for pests are also favorable for natural enemies,” she said. “There is still quite a bit of time before we’ll know for sure, but the possibilities are there for an active spring.”