In the spring, horses and foals can be seen running through pastures, leisurely eating grass and lounging in the sun. However, for every bite they eat, they also produce another product, manure.
Manure management is important year-round, but it is especially important in the spring to prevent runoff that can cause manure to contaminate springs and rivers.
"Manure runoff is an issue in the springtime in particular, as we tend to get rain or snow in large enough amounts to cause runoff at that time of year. Manure has often built up in the winter months, so the manure pack in pens is deeper in the spring, and the combination of manure buildup with high precipitation can lead to runoff issues," said Jessica Davis, Director for Institute for Livestock and the Environment at Colorado State University.
Due to the large number of horses in Colorado, this is a huge issue in the state. "Manure and waste bedding material must be properly handled to ensure that excess nitrates, phosphorous, ammonia and other nutrients are not carried by runoff into waterways or through soil into ground water. Neighbor complaints related to improper management of manure piles or storage areas are also common. Approximately 50 percent of the animal feeding operation (AFO) complaints to which the Environmental Agriculture Program responded in 2011 were directly related to horse manure being allowed to discharge to surface water," said Sean Scott, Colorado Department of Health and Environment's Environmental Agriculture Program Work Lead.
He continued, "Runoff from manure piles and horse paddock areas are rich with nutrients that can contaminate nearby lakes, streams, rivers, wetlands and drinking water supplies used for human and livestock consumption."
By definition, an animal feeding operation must meet the following criteria: (a) Animals (other than aquatic animals) have been, are, or will be stabled or confined and fed or maintained for a total of 45 days or more in any 12-month period, and (b) Crops, vegetation, forage growth, or post-harvest residues are not sustained in the normal growing season over any portion of the lot or facility.
In Colorado, a large concentrated animal feeding operation is any operation with 500 horses or more. A medium operation has between 150 to 499 horses, and a small operation is anything less than 150 horses.
Horse manure is particularly damaging to water because of the composition of it. "Concentrated animal feeding operations are required to contain runoff, but smaller facilities may not have runoff storage ponds in place to prevent runoff from moving offsite. Manure contains nutrients, specifically nitrogen and phosphorus, that can degrade water quality. Manure may also contain pathogens and other contaminants," said Davis.
Proper management of manure is not hard for horse owners to do, and a few simple tips can help protect the water sources from manure run-off, according to Davis. First, corrals and manure piles should be moved away from water bodies. Second, the area between corrals and manure piles and the water should be well-vegetated, which helps reduce the ability of the manure to run off. Lastly, manure should not be kept for years and years, as it will build up.
If manure must be stored, it is important to keep it away from waterways. "The most important thing is to store it away from water bodies or wells in order to protect water quality. It is not necessary to cover it in Colorado due to the semi-arid environment here," said Davis.
Horse owners can use manure on their own place if they spread it over fields. "Horse owners should make sure they don't have too many horses for the amount of pasture that they have. If they do this, they can spread the manure on their pastures and reduce their hay bill. Composting is helpful for improving manure spreading on established pastures," said Davis.
However, she did caution that spreading the manure can cause another problem if the horses are not regularly wormed. "If fresh horse manure is spread on pastures where colts graze, there is a risk of spreading parasites to the colts," she said.
Another use for the manure is as a fertilizer that can be sold or given away. "Horse owners can provide manure to gardeners and farmers for use as an organic fertilizer. Horse owners who hope to sell their manure should have samples of the manure analyzed for nutrient content information, which can be provided to potential agricultural users," said Scott.
He continued, "Manure can be applied to pasture and grazing crops as an organic fertilizer. Horse owners that choose to land apply manure must ensure that manure is applied at an agronomic rate to support vegetative growth. Records should be retained to show the results from soil and manure analyses, manure application rates, and the method(s) used to calculate agronomic rate for each crop to which manure is applied."
Agronomic rate means the rate of application of nitrogen to plants that is necessary to satisfy the plants' nutritional requirements while accounting for applicable nitrogen credits, according to the Department of Public Health and the Environment.
Manure management is key to keeping waterways clean, and to help reduce the impact that manure run-off has on the environment. "If you own or stable horses in Colorado, you may be subject to regulatory requirements designed to protect Colorado's water. Proper management of manure protects Colorado's water resources, improves horse health, keeps land resources productive, protects property values, and minimize neighbor complaints," said Scott.