A grain header is the front harvesting attachment on a combine that cuts, gathers, and feeds cereal crops such as wheat, barley, oats, and rye into the machine. It matters because the header is the first point of contact with the crop, so its design strongly affects harvest speed, grain loss, fuel use, and crop quality. A well-adjusted header keeps material moving smoothly from standing plants into the feeder house.
Poor setup can leave grain in the field or overload the combine.
Key Facts
- Header field capacity can be estimated by area rate = width x speed, with consistent units.
- In hectares per hour, field capacity = width in m x speed in km/h / 10.
- Crop flow path is cutter bar to reel to auger or draper belts to feeder house.
- Reel tip speed is often set slightly faster than ground speed to guide crop without knocking grain loose.
- Cut height affects straw intake, power demand, and grain loss.
- Loss percentage = grain lost / total grain available x 100%.
Vocabulary
- Grain header
- A grain header is the combine attachment that cuts standing grain and moves it into the combine feeder house.
- Cutter bar
- The cutter bar is the reciprocating knife assembly that slices crop stems near the front edge of the header.
- Reel
- The reel is a rotating frame with tines or bats that gently guides standing crop toward the cutter bar and feeding system.
- Feeder house
- The feeder house is the intake conveyor section that carries cut crop from the header into the threshing system of the combine.
- Draper belt
- A draper belt is a moving fabric or rubber belt that carries cut crop sideways and inward toward the feeder house.
Common Mistakes to Avoid
- Setting the reel too fast, which can strike heads hard and shatter grain before it enters the combine.
- Cutting too low, which brings in extra straw and weeds and can reduce capacity by forcing the combine to process unnecessary material.
- Ignoring ground speed changes, which is wrong because faster travel increases crop intake rate and may overload the header or feeder house.
- Treating auger and draper headers as identical, which is wrong because draper belts often provide smoother crop flow across wide headers while augers use a rotating screw to move material inward.
Practice Questions
- 1 A grain header is 9.0 m wide and the combine travels at 6.0 km/h. Estimate the theoretical field capacity in hectares per hour using field capacity = width x speed / 10.
- 2 A field contains 7.5 tonnes of harvestable grain, and header losses are measured at 0.15 tonnes. Calculate the header loss percentage.
- 3 A farmer notices grain heads being knocked forward before they are cut. Explain how reel speed or reel position could cause this problem and suggest one adjustment.