Alfalfa hay is a forage crop known for its high nutritional content. Production is typically measured by the total weight harvested from a specific area, expressed in tons per acre. Converting this weight into “square bales per acre” is complicated because the final number is highly variable. The exact yield depends on environmental conditions, farm management decisions, and the physical characteristics of the bale itself. Understanding these factors is necessary to accurately estimate the annual output from a field of alfalfa.
Standard Yield Expectations
The annual production of alfalfa hay across the United States averages around 3.45 tons per acre. This national figure masks significant variation based on management intensity and local climate conditions. For fields relying solely on natural rainfall (dryland production), the annual yield typically falls between 2 and 4 tons per acre.
In contrast, high-management operations utilizing irrigation and optimal fertilization often achieve yields between 6 and 8 tons per acre. To translate this tonnage into a count of small square bales, a standard bale weight must be assumed. If a small square bale weighs 50 pounds, a dryland field yielding 2 tons produces approximately 80 bales per acre annually. A highly productive irrigated acre yielding 8 tons translates to around 320 small square bales per year.
Primary Environmental and Management Factors
The health and productivity of an alfalfa stand are profoundly influenced by the soil environment and management practices.
Soil and Climate Requirements
Alfalfa requires deep, well-drained soil, as poor drainage promotes root and crown diseases that inhibit growth and reduce stand longevity. A soil pH level between 6.5 and 8.0 is necessary for optimal nutrient uptake and the function of the symbiotic bacteria that fix nitrogen. Beyond soil composition, the availability of water and the local climate dictate the crop’s growth rate and annual yield. While alfalfa is recognized as a relatively drought-tolerant crop, its final dry matter yield is directly proportional to the amount of water it consumes throughout the growing season. High temperatures can hasten maturity, which reduces the overall quality of the forage.
Management Decisions
Management decisions, such as the selection of the alfalfa variety, further impact potential yield. Producers must choose varieties with an appropriate fall dormancy rating, which determines the plant’s winter hardiness and its ability to regrow after harvest. Proper fertilization, specifically the application of phosphorus, potassium, and sulfur, is necessary to sustain the high nutrient demand of an intensively harvested perennial crop.
The Role of Cutting Schedules in Annual Output
The frequency of harvesting, known as the cutting schedule, is a primary management decision that directly impacts total annual output and forage quality. In warmer climates, alfalfa can be cut up to eight times per year, while cooler regions may only allow for three or four cuttings. The choice of cutting interval involves a trade-off between maximizing hay quality and maximizing total tonnage.
Cutting alfalfa more frequently (e.g., every 21 to 28 days) results in forage with a higher concentration of protein and lower fiber, desirable for high-performance livestock. This aggressive schedule, however, can reduce the plant’s stored carbohydrate reserves, leading to lower yield per cut and reduced stand vigor. Conversely, delaying harvest to 35 days or more allows the plant to accumulate more biomass, increasing the yield per cut and often the total seasonal yield. However, hay quality decreases due to increased fiber content. Growers must balance the market demand for high-quality or high-tonnage hay against the long-term persistence of the alfalfa stand. The total number of bales produced annually is a function of the growing season length and the producer’s chosen harvest strategy.
Standardizing Yield by Bale Weight
The term “square bale” introduces significant ambiguity into any yield calculation because it refers to two vastly different sizes of hay package. The small square bale, typically weighing between 40 and 75 pounds, is the type often associated with manual handling and horse feed. However, the larger square bale, commonly used in commercial operations, weighs substantially more, often ranging from 800 to 1,500 pounds.
This dramatic difference in weight means that the same 8-ton-per-acre field that yielded 320 small 50-pound bales would only produce 10 large 1,600-pound square bales. This variation illustrates why yield is always measured most accurately by weight in tons per acre, rather than by a bale count. Bale weight is determined not only by the package size but also by the density of the compression and the moisture content of the hay at the time of baling.
To accurately convert a known tonnage into a specific bale count, a simple calculation is necessary. A producer must first determine the total tons of hay harvested from the field. This total weight is then converted to pounds by multiplying by 2,000, and that figure is divided by the average weight of the specific type of bale being produced. For example, 5 tons per acre, or 10,000 pounds, converted into 60-pound small square bales yields approximately 167 bales.