Hay baling is the final stage in harvesting forage crops such as grasses, alfalfa, or clover. This process involves compacting the dried material into dense, manageable packages for efficient storage and transportation. The primary goal is to preserve the nutritional value of the feed and prevent spoilage caused by moisture. Proper baling techniques ensure the forage remains safe and palatable for livestock. This article covers the steps for preparing, operating, and storing hay bales correctly.
Preparing the Hay for Baling
The process begins with cutting the standing forage using a mower or a specialized mower-conditioner. A mower-conditioner is designed to crimp or crush the stems, which accelerates the drying, or curing, process necessary to reduce moisture levels. The hay must be left to dry in the field under sunlight and natural air movement. This curing phase prevents the later development of mold and mildew.
To encourage uniform drying, farmers often use a tedder to gently fluff and turn the cut material. This action exposes the bottom layers of hay to the air and sun, ensuring all parts of the plant, especially the thicker stems, dry evenly. After the hay has cured, a rake gathers the loose material into continuous, linear rows called windrows. Windrows must be sized to match the pickup width of the baler, ensuring a steady feed rate into the machine.
Determining the hay’s moisture content is the most important factor before baling can commence. Excess moisture, typically above 20%, creates an environment where aerobic bacteria thrive and multiply rapidly. This leads to fermentation and significant internal heating. This bacterial activity causes the hay to degrade quickly, and in extreme cases, the internal temperature can rise high enough to cause spontaneous combustion and a fire hazard.
For standard small square bales, the target moisture range is between 15% and 20%. Large round bales require a slightly lower moisture level to prevent spoilage due to their greater mass and lower surface-to-volume ratio. Farmers use a specialized electronic moisture meter inserted into the windrow to obtain a precise reading. Alternatively, a simple physical test involves tightly twisting a handful of stems; if the stems are brittle and the leaves shatter easily, the hay is dry enough for safe storage.
Operating the Baler
Before entering the field, the baler and tractor must be prepared by inspecting all mechanical components. This involves checking the tension of the knotting system for square balers or the functionality of the wrapping mechanism for round balers. The tractor’s Power Take-Off (PTO) must be set to the correct speed, typically 540 revolutions per minute, to operate the baler’s internal mechanisms effectively.
When beginning to bale, the tractor operator must drive carefully to straddle the windrow down the center of the baler’s pickup head. Consistent ground speed maintains an even flow of material into the pickup mechanism, preventing clogs or the formation of loose bales. The PTO speed must be maintained steadily to ensure the internal compression components operate at the designed rate for proper compaction.
In a square baler, the pickup teeth lift the hay and feed it into a compression chamber where a shear bar cuts the material. A heavy plunger moves back and forth, slicing and compacting the hay against the previous charge. Once the bale reaches the preset length, the knotting mechanism is triggered, quickly tying twine around the compacted material before the finished bale is ejected. The uniform density created by this plunger action allows these smaller bales to stack securely.
Round balers operate differently by using belts or rollers to roll the hay into a cylindrical shape within a fixed or variable chamber. The core of the bale forms first, and subsequent layers are continuously added until the bale reaches its full size and desired density. Once full, the baler stops, and the bale is wrapped tightly with either twine or a mesh net to hold its shape. The chamber then opens and the finished bale is released onto the field.
Adjusting the tension or density setting on the baler is important for producing a stable bale that can withstand handling and storage. The bale must be dense enough to hold its shape during transport but not so tight that it prevents a final degree of moisture reduction post-baling. Overly dense bales trap remaining moisture inside the core, significantly increasing the risk of spoilage even if the initial moisture content was acceptable.
Safe Handling and Storage of Bales
Once ejected from the baler, the heavy, compacted bales require specialized equipment for safe movement and collection. Large round bales are handled using tractor-mounted spears or grapples designed to lift and transport them without damaging the protective wrap. Smaller square bales are often manually loaded onto wagons or moved using bale hooks or specialized accumulators and loaders.
The finished hay must be moved quickly from the field to a dry, protected storage location, such as a barn, shed, or a covered stack yard. Preventing contact with ground moisture is important, often achieved by placing the bales on pallets, gravel, or a plastic vapor barrier before stacking. Proper stacking technique, such as interlocking patterns or pyramid-style stacks, ensures structural stability and prevents collapse.
For small square bales, leaving gaps between the stacks promotes air circulation, which allows for continued moisture evaporation and cooling. Protecting the hay from direct exposure to rain and snow is necessary because rewetting the outer layers introduces new moisture. This rewetting initiates microbial activity, leading to spoilage and mold growth that can penetrate deep into the bale.