By Blake Jackson
Wildfire smoke has become an increasingly common feature of summer across many agricultural regions in the United States. According to Penn State Extension, smoke events now affect nearly one-fifth of growing season days, particularly during July and August. While people can often reduce exposure by staying indoors, crops remain exposed to smoky conditions throughout the growing season.
Smoke from wildfires is made up of a complex mix of gases, particulate matter, volatile organic compounds (VOCs), and biological materials. These components can influence crop growth by changing sunlight, temperature, air quality, and atmospheric chemistry.
The overall impact depends on factors such as crop species, growth stage, smoke intensity, and local weather conditions.
One of the most significant effects of wildfire smoke is its impact on sunlight. Smoke particles scatter sunlight, increasing diffuse light that can penetrate deeper into plant canopies and improve photosynthesis in lower leaves.
However, heavy smoke also reduces the total amount of sunlight reaching crops, limiting photosynthesis and slowing plant growth. Crops are especially vulnerable during reproductive stages, when reduced light can significantly lower yields.
Wildfire haze may also cool daytime temperatures and reduce water loss through transpiration, helping conserve soil moisture during dry conditions. At the same time, smoke particles can accumulate on leaves, interfere with gas exchange, reduce photosynthesis, and delay crop development.
Extended periods of haze may also slow the accumulation of growing degree days, increasing the risk of frost damage in regions with shorter growing seasons.
Smoke can influence rainfall patterns by altering cloud formation and atmospheric stability, although its effects on agricultural production remain under investigation.
In addition, gases such as ozone formed from wildfire emissions can damage plant tissues, reduce crop yields, and increase susceptibility to diseases and pests.
Field observations from the widespread Canadian wildfires in 2023 showed noticeable reductions in solar radiation across parts of the Midwest. Despite these conditions, corn, soybean, wheat, and canola yields generally remained above average because the most intense smoke occurred during crop stages that were less sensitive to reduced sunlight.
Researchers continue studying how wildfire smoke affects crop productivity under different environmental conditions.
Photo Credit: gettyimages-klosfoto
Categories: Pennsylvania, Crops