While data points indicate that the climate is changing, we don’t know exactly what that means for agricultural production. While some experts see the future with a rosier view, others believe detrimental or even catastrophic climate change could affect agriculture in the years ahead.
During an “Illinois-Indiana Climate Series” webinar, Trent Ford, a state climatologist with the University of Illinois, explained that for the last 40 years, the climate has been conducive for high agricultural production of crops such as corn, soybeans, and produce. “Technological advances have been the main driver of this long-term trend,” he added.
But, as the climate continues to change, what will the future bring?
Ford noted that Illinois, for example, has become warmer and wetter, and this trend looks to continue. He said the magnitude of climate change will be driven by human emissions, and that will determine the extent of the impact on agriculture.
The climatologist highlighted several ways a warmer and wetter climate may affect crop production. The first was the length of the growing season. He noted that the growing season in Illinois has extended 10 to 20 days in the last 50 years. This results from both an earlier last freeze in the spring and a later first freeze in the fall.
An earlier spring can lessen issues from delayed planting and emergence. On the flip side, Ford said a longer growing season can result in more weed pressure.
Overall warmer temperatures, especially in the fall, translate to warmer soil temperatures. The extension of warm soils in the fall reduces the window of opportunity for fall fertilizer application, and manure and fertilizer applications made on soil that is too warm can result in nutrient losses. The positive side of this trend is warmer soil temperatures in the spring that allow for earlier planting if precipitation is right and the opportunity for late-planted crops to mature in the fall.
It is not only longer, but the growing season is warmer, too. Ford said we are likely to see a higher frequency of hot days and warm nights during the summer and fall. Those warm nights in particular help add to the heat stress crops experience, and in turn, heat stress can impact silking, reproduction, and grain fill. Hotter summers also worsen disease, insect, and weed stress, compounding the effects of climate change. Ford noted that hot weather elevates the risk of heat exposure for farmers and farm workers, making it a public health issue as well. The warmer summers also feature more humidity, which can exacerbate disease pressure and heat impacts.
Flash drought is another emerging issue he mentioned. Warm summers induce more evaporation, pushing areas into drought conditions faster, Ford explained. High evaporative demand and depleted soil moisture lead to crop stress, which can be made worse in areas with poor soil health and low water holding capacity.
Wetter springs caused by climate change have probably been one of the biggest impacts to agriculture so far, Ford shared. Spring has gotten wetter and is expected to continue getting wetter at a faster rate than other seasons, he noted, and the overall moisture and intense precipitation have been problematic. In particular, spring fieldwork can be delayed due to excessively wet soils, and fieldwork done in wet fields can result in soil compaction and uneven germination and emergence.
Overall, intense precipitation, particularly in the spring and summer, has also been on the rise. Ford shared that in Illinois’ St. Clair County, the likelihood of getting at least 4.5 inches of rain in a single day has doubled since 1989. Heavy rainfalls can lead to standing water, crop inundation, soil erosion, and nutrient runoff.
“Climate change makes important decisions that much more important,” Ford summarized. He advised farmers to make careful decisions when it comes to pest management, nutrient application and timing, cropping rotations, soil conservation practices, and more.