The perennial flowering plant Medicago sativa, commonly known as alfalfa or lucerne, is one of the world’s oldest and most widely cultivated forage crops. Alfalfa meal is the dried and finely ground form of this plant, which concentrates its dense nutritional content into a shelf-stable, easy-to-use product. It serves as a valuable ingredient across multiple industries, including organic agriculture and animal feed formulation, popular for both soil enrichment and animal nutrition.
Transforming Alfalfa into Meal
The manufacturing of alfalfa meal begins with harvesting the crop when it is at its peak vegetative or early bloom stage to maximize its nutritional value. Freshly cut alfalfa contains a high moisture content, often ranging from 75% to 85%, which must be drastically reduced for preservation and storage. The cut plant is typically allowed a brief period of wilting in the field, which naturally lowers the moisture level to approximately 50-60%.
After wilting, the material is transported to a processing facility for industrial drying, often using a large rotary drum dryer. This process exposes the alfalfa to hot air, quickly reducing the moisture content to a stable level, usually between 10% and 12%. This rapid dehydration prevents the growth of molds and mycotoxins while preserving the plant’s heat-sensitive nutrients.
The dried material is then crushed and ground into a fine powder, or “meal,” using industrial equipment such as a hammer mill. This fine grinding breaks down the fibrous stems, making the nutrients more accessible when used as a feed ingredient or a soil amendment. The finished meal is either bagged as a loose powder or further processed into dense pellets or cubes, sometimes with the addition of a binder like molasses for improved handling and palatability.
Key Components and Nutrient Profile
Alfalfa meal provides a complex spectrum of nutrients. Its typical nitrogen, phosphorus, and potassium (NPK) analysis is often reported in a balanced range, such as 3-1-2 or 2.5-0-2.5, recognized for its relative richness in nitrogen and potassium. The meal contains a high percentage of crude protein, often between 17% and 19.5%, which is a primary source of its nitrogen content.
The nutrients within the meal are encased in organic matter, meaning they are released slowly as soil microbes break down the material over time. This slow-release characteristic provides a gentle, consistent feeding for plants, avoiding the rapid nutrient spikes associated with synthetic fertilizers. Alfalfa meal also contributes a wide range of trace minerals, including significant amounts of calcium, magnesium, iron, and zinc, which support various biological processes in both plants and animals.
A unique component of alfalfa meal is the presence of the naturally occurring fatty-acid compound triacontanol. This substance functions as a plant growth regulator, having been shown to stimulate root and stem development. Additionally, the meal contains saponins, which are natural detergent-like compounds that can influence how the meal is utilized, particularly in animal digestion or as a pest deterrent in the garden.
Practical Uses in Agriculture and Feed
Alfalfa meal has two primary applications that leverage its nutrient-rich composition: its use as a soil amendment and its role as a high-quality animal feed.
Soil Amendment/Fertilizer
In gardening and organic farming, alfalfa meal is highly valued as a natural soil conditioner and mild fertilizer. When mixed into the soil or applied as a top dressing, it acts to improve the physical structure of the growing medium. The addition of organic matter from the meal helps to lighten heavy clay soils, while simultaneously increasing the water-holding capacity of fast-draining, sandy soils.
The complex carbohydrates and proteins in the meal serve as a food source for beneficial soil microorganisms and earthworms. This microbial activity is necessary for the breakdown of the organic material, which gradually releases the nitrogen, potassium, and other minerals for plant uptake. Gardeners often mix the meal into compost piles to activate the decomposition process or steep it in water to create a nutrient-rich “alfalfa tea” for liquid feeding.
The triacontanol compound in the meal promotes vigorous root growth and overall plant yield. This makes it a favored amendment for heavy feeders and flowering plants, such as roses. Since it is a mild, slow-release fertilizer, the risk of burning plant roots is low, making it a safe choice for established plants and young seedlings.
Livestock/Animal Feed
As a feed ingredient, alfalfa meal is a concentrated source of highly digestible protein and fiber, making it a staple for many types of livestock. It is most frequently incorporated into the diets of high-producing dairy cows, where its combination of high protein and digestible fiber supports milk production and rumen function. The meal’s crude protein content typically ranges from 16% to 20%, providing the necessary amino acids for growth and maintenance.
The meal is also a widely used component in feed for horses and rabbits, two species with specific digestive requirements. For horses, it is a palatable, grain-free option that provides a concentrated source of calcium, an important mineral for bone health. The calcium content is notably high, often present in a ratio that makes it an excellent supplement for balancing the phosphorus levels in a complete feed.
In poultry diets, dehydrated alfalfa and its leaf concentrates are valued for protein and their high content of carotenoids. These natural pigments are transferred to the eggs, resulting in a desirable deep yellow color in the yolks. The processed meal, particularly in its pelleted form, is convenient for storage, transport, and ensuring consistent nutrient intake.