Diverse Forage Crop Rotation: Alfalfa
alternative practice names:
Perennial Legume; Alfalfa Hay; Hay
Alfalfa (Medicago sativa) is a perennial legume widely recognized for its exceptional nutritional value, making it an ideal forage crop for lactating cows. It is renowned for its high protein content as well as its rich supply of vitamins and minerals, which contribute to improved milk production and overall herd health. Alfalfa is a versatile and valuable crop for dairy farmers, providing both high-quality forage and significant agronomic benefits.
Alfalfa thrives in environments with a long growing season, and its deep root system allows it to access water and nutrients from deep within the soil, making it resilient to drought conditions. As a legume, alfalfa has the unique ability to fix atmospheric nitrogen through a symbiotic relationship with Rhizobia bacteria. This process reduces the need for supplemental nitrogen fertilizers, promoting sustainable farming practices and reducing input costs. Its extensive root system also ensures "living roots" are present for most of the year; its root exudates promote good soil aggregation, preventing erosion and enhancing soil structure.
The crop is typically established in the spring or fall, with seeds sown directly into prepared seedbeds. To aid in initial establishment, farmers sometimes use a nurse crop, such as oats, to protect young alfalfa plants. Alfalfa requires careful management, including multiple harvests per year, to maintain its quality and yield.
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
High-quality forage: Properly managed alfalfa is the gold standard for quality forage. It provides excellent feed for lactating cows and is rich in protein, vitamins, and minerals, contributing to improved milk production and quality.
Steady, year-round forage supply: Alfalfa can provide a consistent supply of high-quality forage throughout the year. Depending on the region, farmers can expect between 3 and 12 cuts of alfalfa annually.
Pest cycle disruption: As part of crop rotations, alfalfa helps break cycles of weeds, insects, and diseases. Its extended rotation from other crops disrupts pest life cycles, reducing the need for chemical inputs in subsequent crops.
Soil health improvements: Alfalfa improves soil health in several key ways, primarily through its deep and extensive root system. These roots enhance soil structure by breaking up compacted layers and improving moisture retention, which increases water infiltration and reduces runoff. Alfalfa also helps prevent soil erosion, protecting the surface layer and preserving valuable topsoil.
Well-suited to flood irrigation: Alfalfa demonstrates high water-use efficiency, even in flood irrigation systems. Its deep roots efficiently capture water applied through flood/furrow irrigation. As a perennial crop maintained for 4-5 years, alfalfa provides consistent high water-use efficiency compared to annual crops that require replanting and have lower efficiency before reaching maturity.
Drought tolerance: Alfalfa is known for its deep root system, which allows it to access water from deeper soil layers, making it more resilient to drought conditions than many other crops. This deep-rooting system enables alfalfa to survive periods of limited water availability, especially during the summer months when rainfall may be low.
Nitrogen fixation: As a nitrogen-fixing legume, alfalfa enriches the soil by adding organic nitrogen through its symbiotic relationship with Rhizobia bacteria, reducing the need for synthetic fertilizers. Subsequent crops like corn benefit from nitrogen credits.
Phosphorus reduction: With multiple harvests annually, alfalfa removes significant amounts of aboveground biomass, which can help manage excess phosphorus in the soil. Harvesting as hay allows for the export of phosphorus off the farm, aiding in nutrient management.

Implementation Insights
Site-specific or Farm-specific requirements

Soils: Alfalfa does best in well-drained soil that is not prone to water logging.
Water availability: Alfalfa typically requires water year-round. Local or state water use restrictions may limit a farm's ability to apply water during certain times of the year and thus grow perennial crops.
Required Capital Expenditures (CapEx)

Soil preparation: Proper soil preparation is crucial for successful alfalfa establishment. A soil pH of 6.5 to 7.0 is ideal for maximizing nitrogen fixation and nutrient uptake. Phosphorus and potassium levels must also be managed through soil testing and appropriate fertilization. Using a nurse crop, such as oats, can help protect young alfalfa plants from frost and reduce erosion, but care must be taken to prevent the nurse crop from competing for moisture and nutrients.
Dedicated storage: Alfalfa requires proper storage to maintain its quality, whether as silage or hay. Investment in facilities like silage bunks or hay storage barns is necessary to preserve the forage’s nutritional value and longevity.
Required Operational Expenditures (OpEx)

There are no major operational expenditures associated with this practice.
Implementation Considerations

Compaction risk: Alfalfa requires multiple harvests per year, necessitating careful management to avoid or reduce soil compaction. Regular traffic from harvesting equipment can lead to compacted soil, adversely affecting root growth and overall plant health.
First-year yield: Alfalfa typically yields less in its first year than in subsequent years. This initial low yield can be a concern for farmers relying on high forage output. To mitigate this, farmers can interseed alfalfa between corn silage, using glyphosate traits for both crops to manage weeds effectively and potentially boost overall forage production.
Land use efficiency: A rotation that includes corn silage and cereal grains generally produces more forage per acre than alfalfa. This higher yield can make it challenging for farmers with limited acreage to incorporate alfalfa into their crop rotation while still meeting the forage demands of their dairy herds. The need to balance land use efficiency with crop diversity and soil health management further complicates the decision to grow alfalfa.
Water availability: Alfalfa typically requires water year-round, although it can respond well to deficit irrigation. Local or state water use restrictions may limit a farm's ability to apply water during certain times of the year and thus grow perennial crops.
Harvest weather: Multiple and timely cuttings per year may be challenging to implement in certain climates.
Financial Considerations and Revenue Streams
FEDERAL COST-SHARE PROGRAM
Funding is available for this practice through USDA's Natural Resources Conservation Service (NRCS) Conservation Stewardship Program (CSP).
Related CSP Enhancement: Resource conserving crop rotation (E328A).
Notes:
Check with the local NRCS office on payment rates and crop rotations relevant to your location.
Crop insurance is now available for alfalfa.
CARBON CREDITS
This practice is commonly credited in carbon markets. The practice can generate both offset and inset credits.
Notes:
To participate, operators generally need at least three years of management data prior to implementing a new practice. Common management data requirements cover planting, tillage, harvest, grazing, fertilization, liming, and residue management.
This practice would need to be new to the producer or expanded to additional acres to qualify for most programs.
In offset projects, producers have to guarantee soil carbon storage for 50-100 years, though avoided emissions (for example, from N2O reductions) do not carry risks of reversals (see Verra methodology and Climate Action Reserve's Soil Enrichment Protocol).
Producers typically are protected against natural disasters or unintended carbon reversals when they contribute to a carbon insurance or "buffer" pool. Intentional reversals from intensive tillage or land sales may require operators to return proceeds from the project.
The length of inset commitments would vary based on the opportunity with the corporate partner.
Credit amounts very widely based on past management, location, weather, and the interaction between practices. A high-level estimate can be calculated using USDA COMET-Planner.
FINANCIAL RESOURCES, TOOLS, AND CASE STUDIES
Additional Resources

Environmental Impacts
REDUCES FARM GREENHOUSE GAS FOOTPRINT
Alfalfa, as a nitrogen-fixing legume, significantly reduces the need for synthetic nitrogen fertilizers, which are major contributors to greenhouse gas (GHG) emissions, particularly nitrous oxide. Studies have shown that legume-based systems emit far less nitrous oxide compared to crops dependent on synthetic fertilizers. Additionally, alfalfa sequesters carbon in the soil through its extensive root system, further lowering a farm’s overall GHG emissions. This helps reduce the global warming potential of agricultural practices.
IMPROVES WATER QUALITY
As a perennial crop, alfalfa protects the soil year-round from runoff and erosion, particularly during heavy rainfall events. Its deep taproots capture nutrients that would otherwise leach out of the soil profile, preventing nutrient loss. By breaking up compacted soil layers, alfalfa improves soil structure and facilitates better water infiltration, reducing surface runoff and contributing to improved water quality.
MAY CONSERVE WATER
Alfalfa demonstrates high water-use efficiency, particularly in flood irrigation systems, allowing farmers to produce more high-quality forage per unit of water compared to many other crops. Its deep root system allows it to access water more efficiently, especially during dry periods, making it a resilient crop in drought-prone regions. Furthermore, alfalfa's perennial nature reduces the need for replanting each year, maintaining high water use efficiency over multiple growing seasons.
SUPPORTS BIODIVERSITY
Alfalfa flowers provide a rich source of nectar for pollinators such as wild bees, and its foliage offers habitat for a variety of insects and small wildlife. The stable arthropod community within alfalfa fields promotes natural pest control. Alfalfa also supports higher trophic levels, such as birds and raptors, by serving as a habitat for key food sources such as voles and other small mammals.
REFerences

Alignment with FARM Program
FARM Environmental Stewardship (ES) V2-V3 Alignment
FARM ES Version 3 includes an optional crop module, allowing users to enter their cropping practices including unique rotations to capture the benefit of those field practices. The optional FARM ES Conservation Practice Questionnaire (CPQ) also includes opportunities for farms to indicate crop rotation.
Contents
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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.
Alfalfa (Medicago sativa) is a perennial legume widely recognized for its exceptional nutritional value, making it an ideal forage crop for lactating cows. It is renowned for its high protein content as well as its rich supply of vitamins and minerals, which contribute to improved milk production and overall herd health. Alfalfa is a versatile and valuable crop for dairy farmers, providing both high-quality forage and significant agronomic benefits.
Alfalfa thrives in environments with a long growing season, and its deep root system allows it to access water and nutrients from deep within the soil, making it resilient to drought conditions. As a legume, alfalfa has the unique ability to fix atmospheric nitrogen through a symbiotic relationship with Rhizobia bacteria. This process reduces the need for supplemental nitrogen fertilizers, promoting sustainable farming practices and reducing input costs. Its extensive root system also ensures "living roots" are present for most of the year; its root exudates promote good soil aggregation, preventing erosion and enhancing soil structure.
The crop is typically established in the spring or fall, with seeds sown directly into prepared seedbeds. To aid in initial establishment, farmers sometimes use a nurse crop, such as oats, to protect young alfalfa plants. Alfalfa requires careful management, including multiple harvests per year, to maintain its quality and yield.
Practices and technologies
Diverse Forage Crop Rotation: Alfalfa
alternative practice name:
Perennial Legume; Alfalfa Hay; Hay