Effects of Flooding on Crops & Livestock
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Understand the effects of flooding on crops and livestock after torrential rain damage. Contamination and disease caused by floodwater are also potential consequences.
by Sherri Talbot
In publications concerning climate issues and livestock, more than three-quarters discussed temperature increases, and about half looked at drought conditions and their effects on farming. Researchers and the media regularly focus on periods of drought in heavily agricultural areas; there’s no doubt that lack of rain for crops and livestock is a common concern for farmers and consumers.
However, too much rain can equally damage farms and food supplies everywhere. Flooding can result in hoof rot, parasites, poor vegetation growth, and other issues. Despite this, a small percentage of publications address the issue.
Crop Flooding
In times of severe flooding, fungal diseases are common and can cause damage to crops. Root-rotting fungi are especially problematic since waterlogged soils promote their growth. Saturation also weighs down the structure of the ground, closing gaps through which air travels and removing oxygen from the soil. The more clay in the soil makeup, the more severe this process can be. In 2009, sections of Russia lost 90 percent of their potato crops, which were decimated by an outbreak of fungi.
Heavy rains also wash nutrients out of gardens and fields, and soil loss from erosion can ruin crops. In some areas, vegetation can even be buried under mud when flooding is especially severe.
Crops grown for animals are also at risk. Saturated soil leaches the nutrients from crops like hay and grass, resulting in a lower nutritional content of the browse. Stored feed, such as hay or silage, may become moldy and useless as livestock feed, resulting in a financial loss for the farmer.
Malnutrition of Livestock
If farmers continue to use feed produced under these conditions, additional concerns can develop with the animals. Low-quality grasses, hay, and silage can result in malnutrition in grazing livestock, leading to illness and poor production. One study showed that poor food quality was directly linked to a decrease in immune system function of many livestock species.
To guarantee proper nutrition, farmers may be forced to supplement or change the diets of their livestock completely. A study revolving around a 2012 flood that impacted much of western England showed major financial losses for farmers due to hay shortages, loss of crops, and the premature sale of animals that couldn’t be fed. These losses don’t end with the floods either. Pastures often need reseeding and fertilization when the rains are over to become productive again, resulting in at least a year of low productivity and losses.
Parasites and Disease Caused by Flood Water
Pastures that have been soaked in stagnant water can be prone to parasites, even after floods have passed. Deadly parasites, such as those that cause meningeal worm and liver fluke, require slugs and snails to complete their life cycle and infest grazing livestock. Wet conditions allow these creatures to thrive and, without preventive treatment or ducks to clean the carriers out of the grasses, illness can be common among livestock for up to a year after flood conditions. The costs around moving animals and finding other housing and grazing areas can be financially crippling, especially for small farms.
Bacterial infections can also increase after floods. Injuries to animals may result in infection, leading to many of these bacteria passing between animals. Environmental conditions increase the risks while malnutrition and stress will make animals less able to fight through health challenges.
In poultry, respiratory infections run rampant. “Hoof rot” becomes far more common in herds or flocks left in wet conditions. Leptospirosis, another bacterial infection, is more likely to develop in herds that experience flood conditions, even a year after the flood.
Fungal infections also increase with flooding. Mastitis, for instance, can be caused by Aspergillus fumigatus – a fungus found in water and soil that requires wet conditions to develop. Reports suggest cases of mastitis increase in livestock for up to a year after exposure to flood conditions. Depending on the area, exposure to other fungi can increase the risks of pneumonia, miscarriages, respiratory issues, and intestinal problems in livestock.
More concerning for the recovery of a farm or homestead is the potential for reproductive issues. In general, extreme climate conditions seem to result in animals having lower rates of conception and birth.
Miscarriages become more common, due to stress, illness, and changes to environment or diet. The potential loss of young, or even breeding animals, means it may take up to three years for herds to return to their expected population size after this kind of natural disaster.
Water Source Contamination
Water supplies can also be affected since flooding can cause contamination from debris, chemicals, parasites, or even dead animals that drown in the flooding. Insects that carry disease are more common. Ironically, this can result in a shortage of drinking water for animals despite the flooding. Contaminated water, combined with injuries, increases the risk of infection following floods.
Farm Flooding Effects
Depending on the time of year and the climate where the flooding takes place, these difficulties can continue long after the waters have subsided. With the number of issues that flooding brings with its rushing waters, farmers can suffer a tremendous amount of financial and personal loss during these times. Furthermore, there’s no quick recovery when the rains cease since fences, fields, and livestock will have a long restoration. Why the impacts of flooding on agriculture get so much less attention remains a mystery.
References
Escarcha, Jacquelyn F., Lassa, Jonatan A. & Zander, Kerstin K. (2018) Livestock Under Climate Change: A Systematic Review of Impacts and Adaptation. Climate, 6(3):54.
Filipe, Joel F., Herrera, et al. (2020). Floods, Hurricanes, and Other Catastrophes: A Challenge for the Immune System of Livestock and Other Animals. Frontiers in Veterinary Science, 7(16).
Gaviglio, Annaet, et al. (2021) A Theoretical Framework to Assess the Impact of Flooding on Dairy Cattle Farms: Identification of Direct Damage from an Animal Welfare Perspective. Animals, 11(6):1586.
Morris, J. & Brwein, J. (2014) The impact of seasonal flooding on agriculture: the spring 2012 floods in Somerset, England. Journal of Flood Risk Management 7(1):101-192.
Sîli, N., Apostu, I., & Faur, F. (2020). Floods and their effects on agricultural productivity. Research Journal of Agricultural Science, 52(4) 113-122.
Ponnamperuma, F.N. (1984). Effects of Flooding on Soils. Flooding and Plant Growth. Academic Press, Inc. ISBN 0-12-42120-4.
Roa, Renuka & Li, Yuncong (2003). Management of Flooding Effects on Growth of Vegetable and Selected Field Crops. Department of Soil and Water Sciences, Tropical Research and Education Center. 13(4):610-616.
Rojas-Downing, et al. (2017). Climate change and livestock Impacts, adaptation, and mitigation. Climate Risk Management. 16:145–163.
Seyedmousavi, S., et al. Infections in animals: a patchwork of different situations. Med Mycol. 2018 Apr 1;56(suppl_1):165-187.
Sherri Talbot is the co-owner and operator of Saffron and Honey Homestead in Windsor, Maine. She raises endangered, heritage-breed livestock and hopes someday to make education and writing on conservation breeding her full-time job. Details can be found at Saffron and Honey Homestead on Facebook at https://www.facebook.com/SaffronandHoneyHomestead.
Originally published in the May/June 2025 issue of Countryside and Small Stock Journal and regularly vetted for accuracy.
