Introduction:
With increasing temperatures and uncertainties about future precipitation patterns, climate change could have serious impacts on agriculture in Wicomico County. Changing temperatures and precipitation patterns have already effected the growing season and increased the need for irrigation throughout the summer. Increasing temperatures will not only damage crops but also place increased stress on livestock. Rainfall will become more infrequent but when we do receive rainfall, it will be heavier, causing further damage to crops as well as increasing runoff carrying agricultural pollutants into our local water bodies. While some plants may initially benefit from the increasing carbon dioxide in the atmosphere, this will ultimately have negative impacts as well.
With increasing temperatures and uncertainties about future precipitation patterns, climate change could have serious impacts on agriculture in Wicomico County. Changing temperatures and precipitation patterns have already effected the growing season and increased the need for irrigation throughout the summer. Increasing temperatures will not only damage crops but also place increased stress on livestock. Rainfall will become more infrequent but when we do receive rainfall, it will be heavier, causing further damage to crops as well as increasing runoff carrying agricultural pollutants into our local water bodies. While some plants may initially benefit from the increasing carbon dioxide in the atmosphere, this will ultimately have negative impacts as well.
"Maryland is already experiencing warmer winters and summers, wetter autumns and springs, and dryer summers. Wet springs delay planting, heavy precipitation and extreme heat events can damage crops, and plants require extra water during increasingly hot summers, further stressing amplified water demand in other sectors. While longer growing seasons could benefit some crops initially, warm weather and mild winters will also increase pressure from weeds and pests and shifting habitats may introduce novel insects and diseases to the region" [1].
- Maryland Commission on Climate Change
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Increasing Temperatures
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Changing Rainfall Patterns
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Impacts of Increased CO2
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Increasing Temperatures:
One of the main impacts on agriculture faced here in Wicomico County is a shift in the growing and planting season [2]. Increased winter temperatures will make for longer growing seasons because of an earlier last spring frost date but will ultimately hurt crops that thrive in cooler temperatures. Though not always recognized directly as an effect of climate change, farmers acknowledge there has been a shift in the calendar of when they can begin to plant crops, about a month later than planting season used to begin [2]. Today, spring planting starts sometime in mid-April, whereas the beginning of the season used to be a month earlier, in March. In the fall, the first frost used to occur in October, but during the 2017 season it didn't come until nearly Thanksgiving [2]. |
Though there has been a shift in the planting season, farmers are still getting the same number of growing degree days, which is a heat index used to predict when a crop will reach maturity [3]. Although some crops will benefit initially from warmer weather and increased levels of carbon dioxide, the benefits won't last long. Warmer winter temperatures will increase instances of disease and parasites within crop species that could jeopardize total crop yields if they are able to spread. The increased risk for summer heat waves bring major concerns for farmers across Delmarva. An increase of just 2-3°F "could decrease corn and wheat yields by 8-14%" [4].
Increased summer temperatures will also further stress livestock as cooling costs increase for farmers. The chicken industry that is a major part of the economy of the Eastern Shore is already seeing negative impacts from climate change that are only going to get worse if something is not done. The State reports that "housing large numbers of birds with a high metabolism in close quarters already makes them susceptible to heat stress during hot summers," only increasing the number of deaths [4]. As temperatures continue to rise, farmers will have to pay more to keep chicken houses cooler to reduce the loss of birds as a result of heat stress.
Increased summer temperatures will also further stress livestock as cooling costs increase for farmers. The chicken industry that is a major part of the economy of the Eastern Shore is already seeing negative impacts from climate change that are only going to get worse if something is not done. The State reports that "housing large numbers of birds with a high metabolism in close quarters already makes them susceptible to heat stress during hot summers," only increasing the number of deaths [4]. As temperatures continue to rise, farmers will have to pay more to keep chicken houses cooler to reduce the loss of birds as a result of heat stress.
Changing Rainfall Patterns:
Although overall rainfall is not expected to increase dramatically, we are going to see more frequent heavy downpours when rainfall is received. When speaking with Charles Wright, owner of Wright's Market, he noted that when he was growing up, they called this area the "little Sahara," as they would get periods of drought in the region that negatively affected crop growth as the intense heat would kill the crops. However, he said that today, his farms "can't miss a storm", and he has had to adopt techniques to better control water on his fields, such as drip irrigation [2]. Increasing summer temperatures and less frequent rainfall will decrease the amount of moisture in the soil causing a greater demand for water. Currently, only 5% of cropland in Maryland is irrigated because rainfall patterns have been able to provide sufficient moisture but a decrease in the number of summer rain events but increase in intensity could cause farmers to have to start irrigating their lands [4]. |
While average rainfall rates over the course of the year have remained the same, farmer Charles Wright noted that rainfall events have become more concentrated. Fields that used to be able to handle two inches or so of rain at a time are now receiving upwards of five inches of rain at once, simply too much water for the crops to handle [2]. More frequent heavy downpours could also jeopardize water quality throughout Wicomico County and the surrounding region by increasing the amount of runoff coming from farms. Heavy rainfall would wash fertilizers, pesticides and manure from fields increasing nutrient pollution in local streams and rivers. This could ultimately lead to increased need for fertilizers and pesticides if they keep being washed away as well as better containment methods put in place by farmers to reduce runoff.
Impacts of Increased CO2:
Increases in carbon dioxide levels in the atmosphere benefit some crops over others. Soy bean production would increase as a result of higher carbon dioxide levels because it acts as a natural fertilizer for plants but the same cannot be said for corn production. Increased carbon dioxide levels would have little effect on corn yields, especially if soil moisture deficits persist, because corn "is already so efficient at absorbing carbon dioxide that it would not benefit much from higher concentrations" [3].
Increases in carbon dioxide levels in the atmosphere benefit some crops over others. Soy bean production would increase as a result of higher carbon dioxide levels because it acts as a natural fertilizer for plants but the same cannot be said for corn production. Increased carbon dioxide levels would have little effect on corn yields, especially if soil moisture deficits persist, because corn "is already so efficient at absorbing carbon dioxide that it would not benefit much from higher concentrations" [3].
Click below to learn about other climate change impacts on agriculture:
References
- 2016 Annual Report. (2016). Maryland Commission on Climate Change. Retrieved from http://www.mde.state.md.us/programs/Air/ClimateChange/MCCC/Documents/MCCC_2016_final.pdf
- Personal communication, Charles Wright, farmer and owner of Wright’s Market, 10 April 2018, Wright’s Market.
- Growing Degree Days. farmwest.com. Retrieved from http://www.farmwest.com/node/936
- Comprehensive Assessment of Climate Change Impacts in Maryland. (2008). Maryland Commission on Climate Change. Retrieved from: http://www.mde.state.md.us/programs/Air/ClimateChange/Documents/FINAL-Chapt%202%20Impacts_web.pdf
- Climate Change and the Cost of Inaction in Maryland. (2011). The Center for Integrative Environmental Research (CIER) at the University of Maryland. Retrieved from: http://mde.maryland.gov/programs/Air/ClimateChange/Documents/2011%20Draft%20Plan/F_Cost_of_Inaction.pdf