Water Quality Issues Associated with Manure

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Many of the images and scenarios on this page may be permit violations or may contribute to exceedances of water quality standards; however, additional information beyond what is provided on this educational page is required to make determinations of that nature. The next topic in this module provides additional information on Clean Water Act requirements.

Challenges In Managing Manure Nutrients

Nitrogen (N) and phosphorus (P) are essential for plant growth. When nutrients are applied in excess of what crops need or when they are applied at a risky time, more nutrients can end up in water than might otherwise have been the case. This holds true regardless of the source of nutrients. This module focuses on manure and some of the challenges in managing manure nutrients.

Economics. Manure contains more than nutrients. Organic matter contributes to soil health and crop growth. Manure also contains water. “Dry” solid manure can be 20-40% water and manure pumped from a liquid or slurry storage is about 90% water. Nutrients in manure are less concentrated than in commercial fertilizers. Relatively speaking, that makes manure expensive to haul long distances. As animal agriculture sectors have consolidated, resulting in larger farms, more manure is produced in smaller areas. Because of the transport expense, manure tends to be applied close to where it is produced.

In areas with many livestock or poultry farms exporting manure, it can be challenging to find fields within a reasonable distance for application. Farmers are beginning to do more manure marketing and some are looking at technologies that can add value to manure. These can offset the costs of transporting manure or can transform manure nutrients into a form that is economical to transport. Related: USDA Economic Research Service “Effects of structural change: manure and excess nutrients” (dairy). The referenced chapter is part of a larger report.

Nitrogen:Phosphorus Ratio. Another important point regarding manure is that it contains more P than N relative to what crops need. If manure is applied at rates to meet the crop N needs, more P than the crop can use in a single year is applied. Over time, P in the soil can build up to levels that present a significant risk for transport to water. Managing this, at least in part, includes a process known as nutrient management planning.

Another way to manage this risk is through the use of the phosphorus index (P-index). The P-index is a risk assessment that factors in several inputs to determine if N-based rates of manure can be used or if application needs to be reduced to a P-based rate. In some cases, the index may show a high enough risk to discontinue P application (manure or otherwise) altogether. To learn more about the P-index, do an Internet search with your state name + phosphorus index. Recommended Resource: SERA-17 publications.(a multistate information exchange group focused on P.)

Variable Nutrient Content. Manure is not a standard product. It varies greatly among animal species and even within species due to varying farm management practices. The most accurate estimate of a farm’s manure nutrient content comes from sampling and manure testing. Recommended Viewing: Iowa Learning Farms videos on liquid manure and solid manure sampling procedures.

Nitrogen Availability. Much of the nitrogen in manure is in organic form. This type of nitrogen is not plant-available (more below) and is slowly mineralized by soil microbes into plant-available forms over several years. The rate at which this mineralization happens is dependent on temperature, moisture, and soil microbial activity, all of which cannot be predicted exactly. Extensive research has led to state-specific recommendations for estimating the amount of nitrogen that will be available to plants each year from manure and other organic sources. Most state Extension services have publications available on this topic.

Recommended Reading: Nitrogen Management on U.S. Corn Acres 2001-10 (USDA Economic Research Service). See Table 3 “Share of treated corn acres that did not meet rate, timing, and method criteria by N source” for data illustrating the challenges of nutrient management and manure.

What Happens When Manure Nutrients Reach Surface Water?

Nutrients, including N and P, are necessary for plant and animal life in streams, lakes, and other surface water bodies; however, a large influx of N, P, or both moves the system out of balance. This enrichment is known as eutrophication.

algae growing in freshwater pond

Photo 1. (Above) Algae is beginning to grow in earnest as the water warms up in late spring.

Aquatic plants and algae grow rapidly under eutrophic conditions (Photo 1).  When the algae or plants die, the decomposition process depletes oxygen dissolved in the water,  a condition known as hypoxia. Without adequate oxygen, fish, shellfish, and other aquatic life die or move to non-hypoxic areas. Another concern is that certain types of algae release toxins that can be harmful to people, pets, or livestock. Excessive algae growth, toxic or not, is referred to as a harmful algal bloom.

Hypoxic zones are an environmental problem, as well as an economic one, as large areas may become unsuitable for commercial fishing, shrimping, and similar activities. The sources responsible for nutrient releases into water vary for each watershed, but usually include agriculture as well as municipal wastewater treatment, urban stormwater, residential areas, and others.

Manure Nutrients in Groundwater

Groundwater is the primary source of drinking water in many parts of the country. The U.S. Environmental Protection Agency (EPA) has set 10 parts per million (ppm) of nitrate (NO3) as the maximum level considered safe for drinking water.

High nitrates occur in surface water as well as groundwater, but are most often discussed as a risk for groundwater because of the large number of private, rural groundwater wells used for drinking water. Municipalities that use surface or ground water for drinking are required to test for nitrates and take corrective action if levels are above allowable limits.

How Do Nutrients Reach Water?

Nutrients are mobile. They cycle and transform in the environment. Even perfectly managed manure handling systems cannot expect to contain 100% of the N and P. Losses can be held to acceptable levels through management and conservation practices. Nutrients from crop fields reach water sources in one of two ways, runoff or leaching. Nutrient runoff occurs when nutrients dissolve in water that flows over the soil surface or when water carries particles of soil containing nutrients to a stream, river, lake, ocean or other surface water. Nutrient leaching occurs when nutrients dissolve in water that is flowing downward through the soil profile.


Manure N is mostly in organic form with a lesser amount of inorganic ammonia. The amount of each varies greatly depending on the animal species and manure collection and storage practices. Once applied to a crop field, a complex network of chemical and biological processes, referred to as the nitrogen cycle, takes over. Organic N from sources like manure or crop residue is mineralized to ammonium (NH4+) and eventually nitrate (NO3).

Organic N and NH4+ are more likely to be associated with soil particles or soil aggregates and may be carried with eroded soil in runoff to surface water bodies. High ammonia levels in surface water are detrimental to aquatic organisms.

Nitrate is soluble and can be carried with runoff or leach downward through the soil profile. When NO3 is carried down below the root zone, it can no longer be captured by plants and used for crop or grass growth. This puts groundwater resources at risk for contamination. Ammonium (NH4+) or organic N are not generally viewed as a risk for leaching.


Phosphorus also cycles through organic and inorganic forms and all, or nearly all, P applied through manure is considered available to plants. Unlike NO3, P binds tightly to soil particles. Rain events capable of eroding soil particles are likely to carry P along with the runoff. To a much lesser extent, P can be soluble (dissolved in water) and carried in runoff, especially when soil P builds up to very high levels. Most P is carried to surface water bodies along with soil.

Phosphorus is not generally a significant leaching risk because of its tight bond to soil particles. There are a few situations, such as soils that are saturated with P or where subsurface (tile) drainage is used, where the risk of P leaching may be substantial.

Recommended Reading: Manure Chemistry: Nitrogen, Phosphorus, and Organic Matter (U.S. Department of Agriculture Natural Resources Conservation Service).

What Are the Risks Associated with Manure and Water Quality?

When it comes to manure nutrients and land application, proper management is critical.

Farm Site Risks

Around the farm site, manure collection and storage as well as uncontained runoff from open lots are the primary risk areas for manure releases or discharges to water (Photos 2 and 4, below).  Many states have rules that require minimum distances between manure storage structures and water, wells, sinkholes, or other environmentally sensitive areas. These distances are called setbacks. The closer that manure is stored near these features, the greater the risk of contamination.

uncontained feedlot runoff

Photo 2. (Above) Uncontrolled feedlot runoff is a risk to water quality. Photo courtesy of U.S. Department of Agriculture Natural Resources Conservation Service (USDA NRCS). Containment systems like those shown in Photos 3 and 5 (below) should be used.

aerial view of feedlot with sediment basin and holding pond labelled

Photo 3. (Above) An example of an open lot feeding operation that not only contains runoff in sediment basins and holding ponds, but also installed a diversion to prevent clean water from entering the feedlot. Photo courtesy of USDA NRCS.

runoff from an open dairy lot

Photo 4. (Above) Water is draining uncontrolled from this lot into the adjacent natural drainage area. Runoff should be managed with appropriate best management practices such as clean water diversions, settling basins, or holding ponds like those shown in Photo 3 (above) or Photo 5 (below).

runoff containment for an open lot with a settling basin in the near and liquid manure storage in the background

Photo 5. (Above) This open lot includes a settling basin (or sediment basin) in the foreground. The animal pens are behind the photographer. When solids have settled out, the liquid is allowed to flow through the pipe into the liquid manure storage in the background. The settling basin is designed for easy access for regular removal of the solids. This two-part system increases the storage life of the manure storage structure in the background by preventing a large portion of solids from entering the structure.

Manure storage structures require careful attention to engineering, construction, operation, and maintenance. If any of these aspects are deficient (Photo 6, below), the structure is at risk for failure. Most problems can be prevented by regular inspection and maintenance. Iowa State University analyzed 58 manure incidents in 2007 and “human error” was identified as the most common cause (13 incidents). They cited things like “leaving pumps unattended” and “failure to close valves” as the type of human errors that occur.

an overflowing manure storage

Photo 6. (Above) An overflowing manure storage. Photo courtesy of USDA NRCS. Regular inspections and timely removal of manure for land application could have prevented this situation. In some areas, covered manure storage structure structures are recommended to prevent rainfall and snowmelt from contacting the manure.

a covered poultry litter storage facility

Photo 7. (Above) A poultry litter storage facility that is covered. The roof keeps the litter dry and helps prevent the problem seen in Photo 6. The structure is nearing full capacity and the photo was taken on the day it was emptied and the litter hauled to fields for land application.  Photo courtesy of Josh Payne, Oklahoma State University.

In addition to manure storage structure failures, manure discharges or spills can be caused by the failure of pumps, hoses or pipes, valves and other handling equipment. The area where manure is loaded into spreaders or tankers is a common area for spills to occur. These spills should be cleaned up quickly to avoid the potential for runoff and to keep the farm site neat.

Transportation Risks for Manure Spills

Moving manure from the farm to the field on public roadways includes the inherent risks that come with traffic. Collisions and overturned tankers or spreaders can result in manure being released onto roads and into ditches.

An overturned manure tanker on a public road

Photo 8. (Above) An overturned manure tanker on a public roadway. Photo courtesy Kevin Erb, University of Wisconsin.

Land Application Manure Loss Risks

During manure application, the risks for manure/nutrient losses include:

  • Overapplication
  • Not observing setbacks
  • Poor timing (weather)

Overapplication. Applying too much manure can be the result of incorrect calculations, incorrect settings on the application equipment, or improperly calibrated equipment. Equipment failures can also lead to too much manure being applied to a field or small area of a field. Overapplication also occurs when there is too little available land for the manure that must be applied.

Setbacks. Many states have setbacks that require minimum distances between land application and water, wells, sinkholes, or other environmentally sensitive areas. The closer that manure is applied near these features, the greater the risk of contamination. This is especially true in locations with karst topography. Sinkholes or fractured bedrock provide a direct path for manure to reach groundwater.

Timing. Weather is an especially important factor in application risk. Applying manure to saturated soils or when drainage tile is flowing increases the risk for both surface-applied and injected manure. Field operations under those conditions also leads to soil compaction which is bad for crop yields and can increase the future risk of runoff.

Frozen or snow covered soils prevent manure from contacting the soil or infiltrating into the soil and also limit or prevent incorporation which is necessary to help stabilize applied manure as part of the soil structure thereby reducing runoff potential. As plants are generally not growing in frozen or snow-covered soils, no agronomic uptake of manure nutrients is occurring either. Applying on frozen or snow covered ground is not advisable and, in many cases, not allowed according to state requirements.

Manure application should be avoided if significant rain is predicted, especially for surface-applied manure that will not be incorporated, and should not begin until soil conditions are favorable.

manure carried by runoff in a field

Photo 9. (Above) Manure application immediately preceding a significant rain event is a high pollution risk and should be avoided. Spreading on this field occurred on the same day as a rainfall and manure was carried by runoff to the base of this field. This photo was taken after another rain event approximately two weeks later, showing more runoff with the potential to further carry manure and nutrients offsite. Making a high-risk application was the first mistake. The second mistake was in not cleaning up the solids as soon as field conditions allowed and re-spreading them when rainfall was not expected. 

field to which manure had been applied 2 weeks earlier and incorporated. The rainfall that day shows no evidence of manure movement

Photo 10. (Above) This was taken the same day as Photo 9 on a field three miles away. The biggest difference is that the manure application (also solid beef feedlot manure) to this field occurred under dry conditions and the manure was lightly incorporated. In the photo, runoff from the rainfall that occurred two weeks after manure application does not appear to be carrying manure from the field; this shows how well the manure was integrated into the soil structure. The manure nutrient runoff risks from this field are much lower than the field in Photo 9.

manure application on snow covered field

Photo 11. (Above) Manure application to frozen or snow-covered soil should be avoided. Some states prohibit manure application during winter months. Managing manure storage levels so that adequate capacity is available to retain manure during extended periods of high-risk conditions (such as winter) is an important management practice.

Other Potential Water Quality Concerns

This page focuses on nutrients and water quality but there are additional manure-related topics of which you should be aware. The following sections very briefly introduce three of these: pathogens, pharmaceuticals, and organic matter.

Microbes and Pathogens

Microbes that are capable of causing diseases are called pathogens. While pathogens make up only a small portion of the microbial world, they get a lot of the attention. Some of the pathogens associated with animal manure include: Escherichia coli O157:H7, Campylobacter spp., Salmonella, and Listeria. The ways that manure pathogens reach water are largely the same as the way manure nutrients travel to water. Recommended: “Manure pathogens and microbial by-products” and “Best practices for pathogen control in manure management systems

An example of a watershed impacted by waterborne pathogens, including those associated with manure, is Samish Bay in Washington. The presence of fecal coliforms at high levels in the bay have made the water unsuitable for shellfish production and recreation. Research is being done on the effects of manure treatment, especially composting and anaerobic digestion, on pathogens in manure. Recommended Viewing: Two webcast presentations “Pathogens 101” and “Microbes: From Farm to Public Risk“.

Biochemical Oxygen Demand (BOD)

We previously discussed the ability of manure nutrients to stimulate plant growth in aquatic systems. Once the “bloom” is over and the plant material begins to decay, oxygen is rapidly removed from water and can lead to fish kills or can lead to long-term hypoxic zones. In addition to nutrients, the large amount of organic matter in manure also depletes water of dissolved oxygen if a significant amount of manure reaches the water body. Runoff from silage or feed piles on livestock farms is another waste stream that has a high BOD and should be contained or controlled just like runoff from manure storage or open lots. Recommended reading: Oklahoma State University developed a comprehensive explanation on organic matter in manure and other wastewater and how it interacts with the environment.

Recommended Resources

The video below was produced by the U.S. Poultry and Egg Association in cooperation with the Livestock and Poultry Environmental Learning Center and U.S. EPA. It covers several water quality topics as well as some air quality concerns. Even though the video references poultry production, it is applicable to other species.

Extension Publications

U.S. Environmental Protection Agency Publications

U.S. Geological Survey Publications

The video below was developed by the University of Wisconsin as part of a series of materials for ag educators related to manure nutrient management.


Previous: Manure Nutrients and Land Application | Next: Regulatory Requirements

These materials were developed by the Livestock and Poultry Environmental Learning Center (LPELC) with funding from the U.S. Environmental Protection Agency and with input from the Natural Resources Conservation Service, National Cattlemen’s Beef Association, National Milk Producers Federation, National Pork Board, United Egg Producers, and U.S. Poultry and Egg Association.

For questions on these materials, contact Jill Heemstra, jheemstra@unl.edu. All images in this module, unless indicated otherwise, were provided by Jill.

Reviewers: Tetra Tech, Inc.; Joe Harrison, Washington State University; Tom Hebert, Bayard Ridge Group; and Mark Risse, University of Georgia

What Is Gasification of Manure?

green stylized pig logoWhen looking at ways to improve the environmental impact of pig production, renewable energy generation is a popular topic. One such technology, gasification, is a series of chemical reactions (see image at bottom) that involve heating a suitable organic material in a controlled, low-oxygen environment to the point that the hydrocarbons (simple organic compounds that contain only hydrogen and carbon) are converted to synthesis gas (‘syngas’). Syngas is composed of hydrogen and carbon monoxide with smaller amounts of methane and carbon dioxide, all of which can be collected and utilized for heat and energy generation.

This manure treatment technology also produces mineral-rich bio-char and ash. Since this bio-char is less bulky than raw manure (and contains most, if not all, of the nutrients) it is much easier to handle and more cost effective to transport long distances. This can be beneficial in areas where nutrients are becoming concentrated on crop fields and contributing to water quality problems. The use of bio-char as a topically applied  soil amendment is currently being  explored for its potential at reducing ionization and thus aiding in the retention of nutrients by impeding chemical transformations and volatilization.

a two ton per hour fluidized bed biomass gasifierMany different organic materials can be used in gasification; wood, plant residues, certain types of manufacturing or household waste, and manure, among other biomass sources. Standard gasification systems utilizes materials that are dry (not pump-able) like beef feedlot manure, poultry litter, or manure that has undergone solids separation. Pig or dairy cattle manure tends to be a wet material and either require drying or a system designed to handle materials like these – wet gasification systems.  Related: Different types of manure gasification systems.

For more information:

chemical representing thermochemical conversion of manure to energy and other products

Image above provided by Dr. Samy Sadaka, University of Arkansas

Authors: Rick Fields, University of Arkansas and Jill Heemstra, University of Nebraska jheemstra@unl.edu


This information is part of the program “Integrated Resource Management Tool to Mitigate the Carbon Footprint of Swine Produced In the U.S.,” and is supported by Agriculture and Food Research Initiative Competitive Grant no. 2011-68002-30208 from the USDA National Institute of Food and Agriculture. Project website.

What Greenhouse Gases Are Emitted by Pig Farms?

green stylized pig logoIn 2014, all man-made sources of greenhouse gas (GHG) emissions in the U.S. were estimated to be 6,870.5 MMT CO2e (millions of metric tons carbon dioxide equivalent). Agriculture was estimated to be responsible 8.3% of those emissions (573.6 MMT CO2e per year). When looking specifically at animal agriculture, all different species together emit an estimated 243.4 MMT CO2e/year, which is 3.5% of all U.S. emissions. The pork industry is estimated to have emitted 26.6 MMT CO2e or 0.34%. (Source: US EPA Greenhouse Gas Inventory 2015)

The two areas where the swine industry produced measurable contributions to agricultural emissions include:

  • Enteric fermentation – the release of gases during normal digestion by animals. Pigs release approximately 2.4 MMT CO2e of the of the 164.3 MMT CO2e produced by all livestock and poultry in the U.S.
  • Manure management – pig farms are estimated to  release 24.2 MMT CO2e of the 78.7 MMT CO2e produced by all animal manure systems in 2014.

Manure management is planned using a total system approach. Animal manure management systems involve six basic functions: production, collection, transfer, storage, treatment and utilization.  The first five out of those six make up the manure management number above. Utilization (usually by land application to crop fields) is instead categorized within “Agricultural soil management”. The greenhouse gases emitted from manure systems include methane and nitrous oxide which form as manure decomposes. 

When all of the GHGs emitted during a particular activity or process are added together, it is the carbon footprint.  The standardized procedure to calculate carbon footprints is a life cycle analysis or LCA.  

Related: Carbon Footprint, Life Cycle Analysis and the Pork Industry

For more information:

Authors: Jill Heemstra, University of Nebraska-Lincoln and Rick Fields, University of Arkansas


This information is part of the program “Integrated Resource Management Tool to Mitigate the Carbon Footprint of Swine Produced In the U.S.,” and is supported by Agriculture and Food Research Initiative Competitive Grant no. 2011-68002-30208 from the USDA National Institute of Food and Agriculture. Project website.

Can feeding pigs less crude protein reduce their carbon footprint? Does it also affect growth and performance?

green stylized pig logoFeeding less crude protein in pig diets can reduce the carbon footprint of that farm, within limits.  Pigs require amino acids (the building blocks of protein) and different protein sources contain different amounts of essential amino acids.

Feed manufactures have begun to make feed grade amino acids (AA) which allow nutritionists and farmers to balance a diet more precisely and feed less crude protein. In turn, this reduces the amount excess nitrogen excreted in the manure (protein contains a great deal of nitrogen). Research has shown that less nitrogen in manure leads to less emissions of gas like ammonia and the greenhouse gas nitrous oxide. Nitrous oxide is nearly 300 times more powerful than carbon dioxide in terms of its ability to trap heat in the atmosphere.

Growth and performance of pigs is not negatively affected when the diet is appropriately balanced for nutrient needs. Meat quality is improved when reducing crude protein in pig diets. Bottom line: this is a highly recommended practice for pork producers and many farmers utilize at least one amino acid (lysine is the most common) in their rations already.

For more information:

  • Research project examining the use of feed grade AA’s to reduce crude protein in swine diets and whether farmers could use more AA’s than is the current industry norm. They concluded that several limiting AAs can be supplemented to reduce crude protein without compromising performance when the economic conditions (especially when the price of soybean meal is high) are favorable to this practice.
  • Principles of balancing swine diets – gives an expanded discussion on AA and other important aspects related to the challenge of formulating pig diets that are precise (reduce waste and excess nutrients as much as possible) and still support performance and profitability.
  • Evaluating the environmental footprint of pork production examines several aspects of raising pigs that are being examined to discover practices to reduce environmental impact of pig farms.

Author: Rick Fields, University of Arkansas and Jill Heemstra, Nebraska Extension jheemstra@unl.edu


This information is part of the program “Integrated Resource Management Tool to Mitigate the Carbon Footprint of Swine Produced In the U.S.,” and is supported by Agriculture and Food Research Initiative Competitive Grant no. 2011-68002-30208 from the USDA National Institute of Food and Agriculture. Project website: https://lpelc.org/integrated-resource-management-tool-to-mitigate-the-carbon-footprint-of-swine-produced-in-the-united-states/.


Weather Trends: State, Regional, and National

`Weather happens and the climate is always changing. Farmers are very in tune with these changes because weather is critical to any farming operation. What are the current weather trends in your area? Is it hotter? dryer? cooler? warmer? Is the growing season longer? Has the first frost date changed?

There is a real possibility that the weather of 30 years ago is not what we are seeing today or will see 30 years from now. The video to the right gives an overview of some of the weather trends. Related: What is the difference between weather and climate?

Use the map below to find weather trend resources in your state. Below the map are regional and national resources on weather and climate trends.

Fact sheet: Is it weather or is it climate? (Slideshare – look below preview box and title for a download link)

Educator Materials

If you would like to use the video, slides, or factsheet for educational programs, please visit the curriculum page for download links for this and other climate change topics.

Recommended Resources

Global Trends

State of the Climate (NOAA)

National Weather Trends

US National Climate  Assessment (US Global Change Research Program)

Midwest Weather Data

Drought Monitor (University of Nebraska-Lincoln)
US EPA Climate Change Impacts on the Midwest
US EPA Climate Change Impacts on the Great Plains

Southeast Weather Data

State of the Climate (NOAA)
Southeast Regional Climate Center-Climate Change and Health in the Southeast

Northeast Weather Data

US EPA Climate Impacts on the Northeast

Southwest Weather Data

US EPA Climate Change Impacts in the Southwest
Managing Changing Landscapes in the Southwestern United States (PDF)

Northwestern Weather Data

US EPA Climate Change Impacts on the Northwestern US
Climate of the Pacific Northwest
US Drought Monitor (Western Region: Upper Colorado River Basin)
Western Regional Climate Center
PRISM Climate Group

About the Author

Pam Knox is a climatologist at the University of Georgia Athens. She has extensive experience in climate and agriculture topics. More about Pam….


This page was developed as part of a project “Animal Agriculture and Climate Change” an extension facilitation project to increase capacity for ag professionals. It was funded by USDA-NIFA under award # 2011-67003-30206.

Biosecurity for Livestock and Poultry Manure Management

Most biosecurity plans are meant to protect animal and human health by preventing the spread of bacteria or other pathogens. Indirectly, effective biosecurity practices can reduce the likelihood of multiple or catastrophic mortalities which is an issue of environmental concern. While not usually discussed under the umbrella of “biosecurity”, manure handling should not be ignored when considering your plan. Related: Manure Pathogens

Avian Influenza | Swine PEDv | Pumping & Land Application | Inspectors | Mortalities | Recommendations by Species

Avian Influenza Resources

In 2015, millions of birds either died or had to be euthanized because of highly pathogenic avian influenza (HPAI). The approved methods of disposal for large-scale (catastrophic) mortalities include: burial, incineration, and composting.

PEDv (Porcine Epidemic Diarrhea virus) Resources

The swine industry has experienced significant losses as a result of PEDv, which can be transmitted through contact with manure of infected pigs. It is possible to move the virus between farms on vehicles, pumps, manure handling equipment, clothing, or any other item that comes in contact with manure and is not thoroughly disinfected between farms/fields. The low amount of viral exposure required to cause illness means that even tiny amounts of residual manure pose significant biosecurity risks.

Preventing Manure Pathogen Dispersal Between Farms or Field

Restricting access of off-farm equipment and personnel involved in manure pumping or manure application and thorough cleaning of equipment between farms are among the recommendations to follow to reduce risks of spreading manure-borne pathogens.

  • North Dakota State Biosecure Nutrient Management. This fact sheet does an especially nice job describing how to manage and clean equipment used in manure handling around the farm.
  • The National Pork Board released fact sheets on Biosecure Manure Pumping Procedures for farmers (pg 20), commercial manure haulers (pg 22), and land owners (pg 20).
  • The Maryland Department of Agriculture developed a brochure related to transporting manure and set out some guidelines to prevent the spread of pathogens.

Biosecurity for Inspectors or Technical Service Providers

What should regulatory inspectors do when traveling between farms to prevent the spread of disease? What requests can farmers make of inspectors to protect their farm biosecurity?

Biosecure Mortality Management

One of the best collections on composting animal mortalities comes from the Cornell Waste Management Institute. Check out their sections on health and safety and animal mortality composting for research on pathogen destruction and other safety considerations.

The following fact sheet was developed in response to the PEDv (porcine epidemic diarrhea virus), although these guidelines should be effective for reducing the risks related to other pathogens. It focuses on the use of rendering as the main mortality disposal method. Biosecure Mortalities Removal (pg 10)

Farmer & Farm Worker Biosecurity Resources

The following resources are not focused on managing manure but give a great overview of the larger biosecurity issue and practices on livestock and poultry farms.

farm worker in a confined swine barn

This farm worker follows the farm biosecurity protocol and is wearing coveralls and boots that are cleaned and laundered on-site.




Beef Cattle

Goats and Sheep

Page Managers: Jill Heemstra, University of Nebraska and John Lawrence, Iowa State University

Adaptation and Risk Management

Food production is dependent on weather and climate. Agriculture must always be planning and preparing for weather or responding to weather as it happens. Adaptation to weather and climate has occurred since farming started and will continue to occur as we move forward in the future. The rate of adaptation is the key to keep up with the rate that the climate changes.

Factsheet: Adapting to a changing climate: A planning guide (PDF; 44 pp)

Climate Change Adaptation is the most common terminology used to discuss how organisms and ecosystems adjust to changing extremes or patterns in weather over time. Most cities and states are drafting plans to help prepare for weather events such as flooding, extreme heat events, disease outbreaks, and others.

Risk Management is a term more commonly used in business and refers to the process of identifying, assisting, and prioritizing of risk followed by some application of resources (usually time or money) to prevent or minimize the negative consequences.

A report from Iowa Beef Center in 1995 discussed a survey of beef producers who lost cattle in a 13 county area over a 2 day period. For those farmers loosing animals, the impact was significant but a quote from the paper sums up the cost benefit decision that must be made when planning for a changing climate.

“How much can a feedlot operator spend to protect against a weather event that has occurred only six times in the last 101 years?”

This is a real and critical question that must be asked. What if this similar type of heat event started occurring every 10 years, or every 5 years? This changes the equation when looking at risk and reward or cost benefit to the implementation of practices or systems to deal with extreme heat.

Adaptation Strategies

Adaptation strategies lay on a continuum with the least drastic listed first (increasing resilience) and most drastic last (transformation).

  • Increasing resilience is a level of adaptation that is similar to what has occurred in the past. As climate changes, technologies or management improves or adjusts to those changes. Resilience has resulted in animal housing, irrigation, diet, genetics, management and other factors that allow farms to be profitable with standard weather variability.
  • Reducing vulnerability is adaptation at the next level with larger and longer term changes in an existing operation to reduce the risk of current or future climate trends. Things such as bringing in heat tolerant genetics, additional cooling capacity in the buildings, or farm diversification. These strategies require a higher investment and are focused on operational changes that allow for profitability into the future.
  • Adaptation through transformation are those changes where the current farming system is nearly abandoned due to climate changes. Complete changes are made in cropping or animals or a new business venture replaces the one on the current site. Transformation might also include the general migration of an industry to a new climate region.

cattle loafing on a bed pack in their barn

Any adaption strategy must be chosen as a function of the site specific features of the farm. Geographic location, current management, current finances, long term and short term farm goals and other considerations need to be made when evaluating farm management and business changes. In addition, the strategy must be based on the current or predicted trends in weather and the impacts this might bring to the farm. A farm prone to flooding in a region where flooding trends are increasing may be interested in a transformational adaptation strategies like relocation than a farm that never experiences flooding.

Cost benefits of these adaptation strategies are not simple. If we were only comparing damage cost to the cost to prevent the damage, the calculation would be simple. Unfortunately, the damage cost is a function of the probability of the weather event and its intensity. For now we must rely on recent weather trends and future climate predictions. Therefore, it is important to be informed about climate change, the impacts of climate change on a local and global level and the economics of adaptation options. Site assessment and planning are key to making good long term adaptation decisions.

Educator Materials

If you would like a copy of the original slides or downloadable copy of the video, please fill out this form. If you use these materials for educational purposes, please send an email to e.whitefield@wsu.edu with how you used the video and how many people watched, to help us improve our resources and document our impact.

Recommended Reading/Viewing

Agricultural Adaptation to Climate Change: Economic and Environmental Implications Vary by Region More… (USDA Economic Research Service, 2012)

Dairy Cattle – Heat Stress

Beef Feedlot Cattle – Heat Stress

Rangeland/Pasture – Drought

Swine Heat Stress

Poultry Heat Stress

Drought: Water Quality and Quantity

Disaster Preparedness Resources


Author: David Schmidt, University of Minnesota schmi071@umn.edu

This material was developed through support from the USDA National Institute for Food and Agriculture (NIFA) under award #2011-67003-30206.

Soil Science and Soil Health for Livestock and Poultry Production

This page is part of a series on environmental management topics developed for young or beginning farmer and ranchers. This series focuses on animal agriculture production and will also be useful to established producers as well as teachers and extension agents/educators.

Why is soil science and soil health important to animal agriculture?

Most livestock or poultry operations recycle manure on nearby land as a fertilizer. On grazing operations, this manure is deposited directly on growing plants by animals. For confined operations, manure is collected and stored until it can be land applied (spread) at an appropriate time. Understanding soil science is important for making the best decisions about manure application rate, location, and timing as well as grazing management.

Soil Science Basics

Soil Health

Soil Characteristics

Soil Sampling

Livestock and poultry farms sample soil to look at nutrient levels and use those in calculating the appropriate amount of manure and/or commercial fertilizer to apply to a field. This is an important step in a process called “nutrient management planning”. To find soil sampling recommendations and testing labs in your state, do a web search for “soil sampling” plus your state name. If you are unable to locate soil testing publications from your state, some recommended resources:

Related: Soil Testing

Knowledge and Tools For Management Decisions

Manure Impacts on Soil

Advanced Topics

Tile drainage and subsurface flow

Teacher/Educator Resources

Oregon State activity http://4hwildlifestewards.org/pdfs/soil.pdf


This Building Environmental Leaders in Animal Agriculture project was funded by the USDA National Institute for Food and Agriculture (NIFA) Beginning Farmer and Rancher Development Program (BFRDP) under award #2009-49400-05871. This project is a joint effort between University of Nebraska, Montana State University, Livestock and Poultry Environmental Learning Community and the National Young Farmers Educational Association (NYFEA). Meet the Beginning Farmer Project Team. For more information about this project or this web page, contact Jill Heemstra jheemstra@unl.edu

Orienting Buildings Perpendicular to Prevailing Winds May Reduce Odors

Scientists from USDA’s Agricultural Research Service (ARS) are taking a sideways look at odors, literally.

As anyone that has evaluated potential sites for swine facilities knows, many factors–such as wind speed, direction, topography, vegetation, and more–influence the potential impacts on downwind neighbors. In an effort to understand how air currents interact with the building site–and therefore pick up odors, dust, and other emissions–Tom Sauer and Jerry Hatfield, with the National Soil Tilth Laboratory in Ames, Iowa, built a model swine farm in a wind tunnel.

Research Activities

Air flow velocities and turbulence intensities were measured with a sensor that measured how quickly the winds carried heat away at 83 points behind the building models. They also took pictures of smoke patterns, generated by dry ice, to capture airflow patterns around the model structures and measured evaporation rates from the model storage tanks and lagoons. They reconfigured the model farm in different ways and repeated their measurements.

What Did They Learn?

Buildings situated perpendicular to airflow disrupted downwind airflow to a greater extent than buildings parallel to airflow. “These studies show how much the placement of animal housing units and manure-storage facilities can work in combination with prevailing winds and site conditions to affect the distance that potential agricultural air emissions can travel,” says Sauer. “They strongly indicate that we should be able to reduce the downwind air-quality impacts from animal production by modifying the layout of a production facility.”

Using model farm buildings, silos, and trees (wire mesh coils serve as trees), agronomist Guillermo Hernandez (left) and soil scientist Tom Sauer evaluate the effect of model arrangements on airflow. Hernandez makes an adjustment to one of the highly sensitive probes as Sauer monitors the real-time data signal. Photo courtesy of the USDA Ag Research Service.

Additional Information

  • “Tunnel Vision” Tracks Emission Dispersal was published in the September 2008 issue of Agricultural Research magazine.
  • This research is part of Air Quality, an ARS national program (#203).
  • Thomas J. Sauer and Jerry Hatfield are with the USDA-ARS National Soil Tilth Laboratory, 2110 University Blvd., Ames, IA 50011-3120; phone (515) 294-3416 [Sauer], (515) 294-5723 [Hatfield].

October, 2008 Newsletter Articles

  • EPA Releases “Report on the Environment 2008”
  • Poultry Waste Management Symposium To Be Held October 21-23
  • US Geological Survey National and Regional Trends in Ground-Water Quality

This summary was adapated from materials provided by the USDA ARS. It has not been peer reviewed and represents the newsletter editor’s summary of the research.

Phosphorus Mass Balance on Livestock and Poultry Operations


This fact sheet has been developed to support the implementation of the Natural Resources Conservation Service Feed Management 592 Practice Standard. The Feed Management 592 Practice Standard was adopted by NRCS in 2003 as another tool to assist with addressing resource concerns on livestock and poultry operations. Feed management can assist with reducing the import of nutrients to the farm and reduce the excretion of nutrients in manure.

Please check this link first if you are interested in organic or specialty dairy production

The Natural Resources Conservation Service has adopted a practice standard called Feed Management (592) and is defined as “managing the quantity of available nutrients fed to livestock and poultry for their intended purpose”. The national version of the practice standard can be found in a companion fact sheet entitled An Introduction to Natural Resources Conservation Service (NRCS) Feed Management Practice Standard 592. Please check in your own state for a state-specific version of the standard.

Mass balance is calculated as the difference between imported and exported mass across the farm boundary. Estimating mass balance can provide critical information for (comprehensive) nutrient management planning and to manage the movement of nutrients and manure. Estimation of whole-farm P mass balance is used to determine the acres of land needed for crop production to use manure P. Environmental risk to surface and ground waters is increased if the amount of P imported into the farm (e.g., from fertilizers, feeds, and animals) exceeds the amount of P exported from the farm (e.g., crops, animals, manure, milk, meat, eggs, and fibers).

In Table 1 are estimates of P excretion derived by mass balance calculations using standard diets, animal performance, and the acres needed for land application at a crop removal rate of 50 pounds P2O5/acre per year. Mass balance estimates vary among farms, depending upon specific inputs and outputs, and should be calculated specifically for each farm when doing nutrient management planning.

Table 1. Examples of annual phosphate (P2O5) excretion and acreage needed for various livestock enterprises per 1,000 head of production to maintain zero P mass balance (imported P = exported P) annually.
Livestock Enterprise Pounds P2O5 Acres needed
Growing-finishing beef 17,500 350
Horses 22,000 440
Lactating dairy cows 86,000 1,720
Dairy heifers 27,000 540
Laying hens 1,200 24
Cow-calf beef 48,000 960
Sheep 13,500 270
Swine breeding herd with phytase 37,000 740
Swine growing-finishing with phytase 3,600 72
Turkeys with phytase 1,300 26

Ways to affect P mass balance

Farms may consider moving manure off site to reduce P mass balance if not enough acreage is available. Additionally, potential feeding strategies to reduce P balance (and excretion), feed costs, and necessary land base include the following:

  1. Routinely complete laboratory analyses of feeds and re-balance rations as needed to meet animals’ P requirements.
  2. Formulate rations to meet the animal’s P requirements for maintenance, lactation, growth, and pregnancy. In general for a lactating Holstein cow, 1 gram of P for each pound of milk produced is sufficient to meet these combined requirements. Based on this, ration P should equal 0.32 to 0.38% in DM depending on feed intake and milk yield (NRC, 2001). Greater concentrations are not necessary unless feed intake is depressed.
  3. Beef and dairy cattle rations may not need P supplementation at all to meet the animals’ requirements if basal ration ingredients have high P concentrations. Discontinuing P supplementation may reduce land base required by 25 to 50% (depending on the amount of over-supplementation in the original feeding program).
  4. If typical rations (e.g., corn silage, soybean meal, alfalfa, and corn grain) contain more P than needed to meet requirements, and if land base is limiting, alternative feedstuffs should be considered. The cost of using alternative feedstuffs may be less than the cost of using common “least-cost” feeds and managing excess manure P.
  5. Swine and poultry are able to absorb only part of the P in diets, so formulate based on “available P.” Grains for swine and poultry can vary from 14 to 50% in available P. In contrast, over 90% of ration P is available to cattle and sheep due to rumen microbial phytase.
  6. Supplemental phytase in corn-soybean meal based-diets for swine and poultry increases the P availability so that 25 to 35% less total ration P is needed.
  7. Pelleting and reducing the particle size of rations can increase the efficiency of P use by swine and poultry by 5 to 10%.
  8. Formulating rations for specific production phases, genotypes and genders. “Phase- feeding” programs for growing swine, poultry and lactating dairy cows can reduce P imports and excretion at least by 5 to 10%.


National Research Council. 2001. Nutrient Requirements of Dairy Cattle. 7th rev. ed. Natl. Acad. Sci., Washington, DC.

“Extension programs and policies are consistent with federal and state laws and regulations on nondiscrimination regarding race, sex, religion, age, color, creed, national or ethnic origin; physical, mental or sensory disability; marital status, sexual orientation, or status as a Vietnam-era or disabled veteran. Evidence of noncompliance may be reported through your local Extension office.”



This fact sheet reflects the best available information on the topic as of the publication date. Date 5-25-2007

This Feed Management Education Project was funded by the USDA NRCS CIG program. Additional information can be found at Feed Management Publications.

Image:Feed mgt logo4.JPG

This project is affiliated with the LPELC.


Project Information

Detailed information about training and certification in Feed Management can be obtained from Joe Harrison, Project Leader, jhharrison@wsu.edu, or Becca White, Project Manager, rawhite@wsu.edu.

Author Information

David Beede
C.E. Meadows Professor
Dale Rozeboom
Associate Professor
Department of Animal Science
Michigan State University

Reviewer Information

Brian Perkins – Consulting Nutritionist

Katherine Knowlton – Virginia Tech