Harvest Operations

Illustration 4: A self-propelled harvester loading into a truck on-the-go. Source: Scott Sanford

Significant energy is required to chop, and store forage material. Roughly 40 percent of the energy needed by a forage chopper is used for cutting [9]. Keeping knives sharp and in close tolerance to a shear bar, along with avoiding a shorter length-of-cut than is required for good storage, has significant impact on energy use [11]. Kernel processor rolls are used to crush and crack corn kernels and cobs to make them more digestible but provide no benefit for hay forage crops, therefore they should be removed before chopping hay crop silage.

Sharp knives also reduce energy required by mower/conditioners and balers. On cutterbar mowers knives should be in close proximity and register with guards. Conditioning roll clearance should be adjusted for adequate but not excessive crimp pressure to speed stem wilt . A sharp knife and the recommended plunger clearance will reduce energy required for square balers.

Many improvements have been made to merging or inverting equipment used for hay crop forage. Merging windrows saves fuel by better matching harvester or baler capacity with crop yield. Harvesters and balers work more efficiently, and take less fuel per ton of crop, if they are operated close to capacity. If the harvester is picking up a single swath and not load-ed near machine capacity, the operation will take longer and waste fuel. Rakes can be used to merge windrows and promote drying by turning windrows and exposing new surfaces to air movement and sunlight.

Forage blowers require significant amounts of energy to move crops into silos. Keeping proper clearance between the blower fan blades and the fan housing and maintaining straight, dent-free blower pipe are key to saving energy. Check the operation manual for recommended fan tip clearance. A common rule-of-thumb is that blades should “move a nickel but pass over a dime.”

Grain harvest combines utilize a governed engine to operate: gathering, threshing, separating, cleaning, and conveying the crop. Some attachments, such as a rear-mounted chopper and chopping corn heads, have significant power require-ments. Because the engine is loaded (with some reserve capacity) for these operations plus movement through the field and grain unloading, good engine maintenance and attention to those tasks needing the most power are the main ways to save fuel. Replacing worn chopper knives, checking belt tension, and closely following engine maintenance (such as air and fuel filter replacement) guidelines has a direct effect on fuel efficiency.

Chopping corn heads are becoming increasingly popular to harvest corn grain and chop remaining corn stalks into 6 to 8” long pieces in one pass over the field thus eliminating a separate operation with a tractor and stalk chopper. It Is estimated that chopping corn heads require an additional 0.7 to 1.5 horsepower per row depending on conditions which is much less than a separate trip over the field with a stalk chopper would require. However if you are planning on harvesting the stalks, you may need to use a stalk chopper to shed and reduce the length of the stalk pieces.