Hay is a harvested crop of forage plants, most commonly grasses or legumes, dried for use as animal feed when pasture is unavailable. The primary goal of cutting hay is to capture maximum nutritional value and initiate curing, which rapidly reduces the plant’s moisture content. This mechanical process requires balancing plant maturity, weather conditions, and operating heavy machinery. Precision and preparation are mandatory for a successful harvest that converts field growth into storable, high-quality feed.
Optimal Timing and Field Readiness
The decision of when to cut is tied to the forage’s maturity stage, which determines its feed quality. As a plant matures, its fiber content, specifically lignin, increases, diminishing the nutritional value by locking away protein and digestibility. To maximize nutrient retention, growers aim to cut legumes like alfalfa before the first flowers open and grasses before the seed heads fully emerge. The harvest hinges on securing a weather window of at least three consecutive dry days following the cut to allow for proper curing.
Before cutting, a thorough inspection of the field is necessary. Obstacles like hidden rocks, fence posts, or tile holes can cause significant damage to the mower’s cutter bar, leading to costly repairs. Field moisture content is the most critical factor; hay baled too wet can spoil or spontaneously combust in storage. For safe dry-hay storage, moisture must be between 15% to 18% for large bales and 13% to 15% for small square bales.
Selecting and Preparing Cutting Implements
Selecting the appropriate implement depends on the scale of the operation and the type of forage being harvested. Disc mowers use high-speed rotating discs and are favored for cutting quickly and cleanly without clogging, even in thick crops. This efficiency comes with a higher cost and requires substantial Power Take-Off (PTO) horsepower for wide headers. Sickle bar mowers operate with a scissor-like, reciprocating action, are less expensive, and require minimal horsepower, making them suitable for smaller tractors and fields.
Drum mowers offer a compromise, being durable and immune to clogging, allowing for high travel speeds similar to disc mowers. However, the complexity of a disc mower’s gearbox means that repairs can be expensive when a major obstruction is encountered. Regardless of the type, the mower requires pre-operation attention, including checking the gearbox fluid level and ensuring all blades are sharp. Dull blades tear the crop instead of slicing it cleanly, which impairs plant regrowth and leads to a poor-quality cut.
Operational Cutting Strategy
The cutting process requires balancing the tractor’s speed with the quality of the cut and the mower’s capacity. While advanced disc mowers can operate up to 10 miles per hour in ideal conditions, a common range for a clean cut is between 4 and 6 miles per hour. The first step is to establish a headland by making two perimeter passes around the field, creating a clear area for turning the tractor and implement. The rest of the field is then cut in a back-and-forth pattern, minimizing sharp turns that stress the drivetrain and the mower’s hitch.
The height of the cut affects both yield and plant regrowth. Leaving a stubble height of three to four inches promotes faster recovery for the next cutting and keeps the forage off the moist soil, reducing contamination and speeding drying. Many modern implements incorporate a conditioner—rollers or flails that crimp or crush the stems immediately after cutting. This mechanical damage to the waxy outer layer allows internal moisture to escape, potentially accelerating the drying rate by 15% to 25%. A wide swath spread maximizes the cut crop’s exposure to the sun and air, significantly reducing curing time compared to a narrow windrow, which is only necessary when soil moisture is high.
Essential Safety Practices
The operation of heavy tractor and PTO-driven equipment demands strict adherence to safety protocols. The Power Take-Off shaft rotates at high velocity, and its safety shield must always be correctly installed and functional, as contact with an exposed shaft can cause severe injury. Before dismounting the tractor for any reason, such as clearing a jam or making an adjustment, the PTO must be fully disengaged and the engine shut off.
When operating on public roads, the tractor and implement must be clearly visible to other motorists. This is accomplished by displaying a clean, unfaded Slow-Moving Vehicle (SMV) emblem—a fluorescent orange triangle visible up to 500 feet away. Operating on slopes or uneven terrain requires reduced speed to maintain stability and prevent the tractor from tipping over. A cautious approach prevents equipment damage and protects the operator from accidents involving high-mass, high-power machinery.