Composting: Static Stacking and Windrows
alternative practice names:
Bin Composting; Static Pile; Passive Composting; Active Composting
Composting is used to treat organic bedding, manure, waste feed, and other organic byproducts. Many dairies opt to compost their manure and handle it as a solid. The term "compost" on dairy farms can refer to both true composted manure and manure that has undergone some level of incomplete composting.
True compost: This is accomplished through aerobic decomposition, where organic materials are exposed to specific temperatures ranging from 90°F to 140°F for a sustained period of time. Traditional composting on dairy farms involves creating windrows or piles of manure mixed with other organic materials and turning them frequently. Alternatively, farms can use static piles with active aeration to move air through the piles using blowers. Advanced techniques for true composting include in-vessel or drum composting, composted bedded packs, and vermicomposting, which are discussed in detail on other pages.
Partial compost: This refers to manure that has not completed the entire compost cycle or has been treated using a combination of anaerobic and aerobic management practices. The most common method of generating partial compost is stacking manure in a pile and turning it intermittently but not at the regular intervals necessary to produce true compost. Static stacks/piles with passive aeration create a partial compost.
When used, in what regions in the U.S. is the practice found:
Northwest, West, Upper Midwest, Southwest, Northeast, Southeast
FARM SIZE
When used, typically found on farms of the following sizes:
All Sizes

Practice Benefits
Reduction in waste and mass volume: Composting generates heat through microbial activity, which evaporates water content from the compost pile. This process significantly reduces the mass and volume of manure, lowering hauling and transport costs.
Enhances manure treatment: Composting converts raw manure into a safe soil amendment, reducing environmental risks. This process stabilizes nutrients, creating a balanced, slow-release fertilizer that enhances soil fertility and crop yields. The heat produced during composting also kills weed seeds and pathogens, resulting in cleaner and safer manure for crop application.
Diversified income and nutrient export: By selling compost, farms can diversify their income streams and export excess nutrients, contributing to overall farm profitability.
Reduction of odor: Composting breaks down odorous compounds in manure, reducing smells.
Improved manure handling: Composted manure is more homogeneous, making it easier to handle, spread, and incorporate into the soil compared to raw manure. This ease of handling enhances operational efficiency and effectiveness.

Implementation Insights
Site-specific or Farm-specific requirements

Solid and semi-solid manure: Depending on housing type and management, dairies can produce various solid and semi-solid waste streams that can be composted. Nearly all dairies have some waste streams that can be composted, such as manure from bedded calf facilities, heifer barns, dry lots in dry climates, dry-cow pens, and special needs pens. Farms that manage manure as a liquid can generate compostable manure solids through solid-liquid separation. In warm, dry climates, farms that manage manure as a slurry can solar dry the slurry or apply it to existing solid manure piles where it can be composted.
Required Capital Expenditures (CapEx)

Equipment: For partial composing, a farm will need access to a front-end loader or excavator to move static piles. Windrow composting can also be accomplished with the aforementioned machinery, but larger operations may want to invest in a windrow turner.
Shelter: In cooler climates with significant moisture, a cover or roof may be needed to control precipitation.
Concrete slab: A concrete slab provides a workable base and prevents soil leaching or erosion.
Required Operational Expenditures (OpEx)

Carbon-rich organic matter: Creating a true compost requires a specific ratio of carbon to nitrogen. Bulking agents like straw, sawdust, or wood chips may be required to balance the carbon-to-nitrogen ratio and improve aeration.
Labor: Personnel are needed to handle manure, manage the composting process, turn the compost, and monitor its progress.
Implementation Considerations

Monitoring the compost cycle is critical to developing a true compost; farmers must regularly manage the pile's carbon-to-nitrogen ratios, moisture, and temperature and be prepared to troubleshoot as necessary.
Loss of nitrogen: During composting, nitrogen is lost mainly through ammonia volatilization and leaching. Ammonia can be released into the atmosphere as manure decomposes, especially if the compost is not adequately aerated or if the carbon-to-nitrogen ratio is not balanced. Excess moisture or inadequate composting conditions can lead to leachate, which washes away nitrogen compounds from the compost. With either outcome, the nitrogen content in the composted manure may be lower than in the raw manure. Farmers transitioning to a composting system may need to import commercial nitrogen fertilizers to ensure their crops receive adequate nitrogen, compensating for the losses and meeting crop nutritional needs.
Financial Considerations and Revenue Streams
FEDERAL COST-SHARE PROGRAM
Funding is available for this practice through USDA's Natural Resources Conservation Service (NRCS) Environmental Quality Incentives Program (EQIP).
Related EQIP Practice Standard: Composting Facility (317).
Notes:
Check with the local NRCS office on payment rates and practice requirements relevant to your location.
To quality for EQIP funds, the dairy is required to obtain a Comprehensive Nutrient Management Plan (CNMP) to guide practice implementation.
FINANCIAL RESOURCES, TOOLS, AND CASE STUDIES
Additional Resources
► See the Newtrient Solutions Catalog to learn more about Composting and related solution providers.
Article: Aerobic Composting Affects Manure's Nutrient Content (Northeast Dairy Business)
Article: Exploring Different Composting Options (Manure Manager)
Book Chapter: NRCS National Engineering Handbook (NEH) (Title 210), Part 637, Chapter 2, “Composting.” (USDA-NRCS)
Handbook: On-Farm Composting Handbook (NRAES 54) (Cornell University)
Report: Composting Animal Manures (North Dakota State University)
Report: Manure Treatment Technologies (Cheasapeake Bay Program)
Video: On-Farm Aerated Static Pile Composting Fundamentals (Whatcom Conservation District)

Environmental Impacts
MAY REDUCE FARM GREENHOUSE GAS FOOTPRINT
Composting can reduce methane emissions compared to traditional anaerobic lagoon or liquid/slurry storage systems.¹ Greenhouse gas (GHG) emission reductions from composting will vary depending on factors like moisture content, temperature, pH, and the carbon-to-nitrogen ratio of the starting material.² Methane production is lower because the manure is stored in aerobic conditions, which inhibit the anaerobic processes responsible for methane generation. Composting increases the emission of ammonia compared to anaerobic lagoon or liquid/slurry storage systems³ and has a variable impact on nitrous oxide emissions.
See research highlights:
Fillingham et al. (2017) concluded that active composting produces low emissions of N₂O and CH₄, with most carbon being emitted as CO₂-C and most N as (NH₃)-N.
IMPROVES WATER QUALITY
Composting stabilizes nutrients through microbial activity and biochemical processes, converting nitrogen into less volatile forms and reducing the risk of nutrient leaching and runoff. This stabilization minimizes the potential for nitrogen runoff and leaching (Goldan et al., 2013).
────────────────
¹ When manure is stored and handled as a solid instead of a liquid, there is a significant opportunity to reduce manure-related GHG emissions, regardless of the composting method used. Farms that manage manure as a liquid or slurry can separate and compost the manure solids. In certain climates, farms may be able to solar dry slurry manure, converting it to a solid form that can be handled and composted. Any solid-stack manure can be composted as well.
² Ba et al. (2020) reviewed the GHG emissions associated with different compost management techniques. They concluded that there are large differences in gaseous emissions from different composting methods. Turning composting resulted in larger carbon and nitrogen losses compared to other composting methods.
³ Active is associated with greater ammonia losses. Introducing extra oxygen through frequent turning or via pipes can increase both ammonia and nitrous oxide emissions. NH₃ itself is not a GHG, but it plays an indirect role in increasing global N₂O emissions. When ammonia is deposited onto soils or water bodies, microbial processes can convert it into nitrous oxide, a potent GHG.
REFerences

Alignment with FARM Program
FARM Environmental Stewardship (ES) V2-V3 Alignment
FARM ES Version 3 offers composting as a manure management data input. Users can specify if they are doing intensive windrow, passive windrow and static pile.
Contents
We're always eager to update the website with the latest research, implementation insights, financial case studies, and emerging practices. Use the link above to share your insights.
We're always eager to update the website with the latest research, implementation insights, financial case studies, and emerging practices. Use the link above to share your insights.
Composting is used to treat organic bedding, manure, waste feed, and other organic byproducts. Many dairies opt to compost their manure and handle it as a solid. The term "compost" on dairy farms can refer to both true composted manure and manure that has undergone some level of incomplete composting.
True compost: This is accomplished through aerobic decomposition, where organic materials are exposed to specific temperatures ranging from 90°F to 140°F for a sustained period of time. Traditional composting on dairy farms involves creating windrows or piles of manure mixed with other organic materials and turning them frequently. Alternatively, farms can use static piles with active aeration to move air through the piles using blowers. Advanced techniques for true composting include in-vessel or drum composting, composted bedded packs, and vermicomposting, which are discussed in detail on other pages.
Partial compost: This refers to manure that has not completed the entire compost cycle or has been treated using a combination of anaerobic and aerobic management practices. The most common method of generating partial compost is stacking manure in a pile and turning it intermittently but not at the regular intervals necessary to produce true compost. Static stacks/piles with passive aeration create a partial compost.
Practices and technologies
Composting: Static Stacking and Windrows
alternative practice name:
Bin Composting; Static Pile; Passive Composting; Active Composting