Power harrow
A power harrow is a PTO-driven cultivator with a row of rotors, each carrying a pair of vertical tines that spin across the ground. It breaks ploughed or cultivated soil down into a fine, level seedbed, and is often teamed with a seed drill to sow in the same pass.
Tractor power needed: About 80 hp for a 3 m machine up to around 400 hp for a 6 m folding harrow
How it works
The PTO shaft drives a gearbox on top of the machine, which turns a line of large gears inside the main beam. Each gear spins a rotor carrying two tines that point down into the soil. Neighbouring rotors turn in opposite directions and their paths overlap, so the whole width is worked. Because the tines turn flat across the ground, the soil is broken and mixed at working depth without bringing wet or stony soil to the top.
A levelling board behind the rotors smooths the surface, and a roller at the back carries the weight, sets working depth and firms the seedbed. Rotor speed can be changed by swapping gears or sprockets in the gearbox: faster for a finer tilth, slower in soil that is easily overworked. A cam clutch protects the drive if a tine meets a big stone.
Main types
- Rigid power harrow: One-piece machines from about 2.5 to 4 m wide, the usual choice for mixed farms and combination drilling.
- Folding power harrow: Wider machines of 4 to 6 m that fold to 3 m for the road, built for big tractors working alone.
- Combination with a drill: A drill sits on a linkage on the harrow so the seedbed is made and sown in one pass. Heavy-duty linkages lift 2,500 kg or more.
- Roller choice: Packer rollers suit heavy, sticky clay; open cage or crumbler rollers suit dry, lighter conditions; toothed and ring rollers suit drilling.
Hooking it up to a tractor
Power harrows hang on the three-point linkage and take their drive from the PTO, on most modern machines at 1,000 rpm. Kuhn's 3 to 4 m models need from about 80 to 100 hp but heavier versions can take up to 250 hp. Amazone's 6 m folding machine is built for tractors of up to 400 hp. Never put more power through the gearbox than the maker allows.
A short history
Dutch firm Lely, founded in 1948, launched its Terra power harrow in 1968, and the machine became the company's big international breakthrough. Power harrows spread quickly through Europe as farmers looked for a faster way to work ploughed land into a seedbed, and makers such as Kuhn, Amazone, Lemken and Maschio now build wide ranges.
Buying and care tips
- Gearbox and beam: Check oil level and look for leaks around the rotor seals. Listen for grinding while turning the rotors by hand.
- Tines: Measure tine length against new. Hard-coated tines last much longer, and tool-free quick-change systems save time.
- Roller and bearings: Check roller bearings and scrapers, and pick a roller type that suits your soil.
- Match the tractor: Stay within the harrow's maximum power rating, and check your linkage can lift a harrow and drill together.
- Stones and debris: In stony fields look for tine holders shaped to shed stones, spring-loaded side plates and track eradicators that can ride over obstacles without damage.
Questions people ask
What is the difference between a power harrow and a rotavator?
A power harrow's tines spin on upright shafts, mixing soil without turning it over. A rotavator's blades spin on a horizontal shaft and chop and mix the soil more aggressively.
Can you use a power harrow straight after ploughing?
Yes, it is one of its main jobs. A power harrow, often with a drill on top, can turn ploughed land into a sown seedbed in one pass.
What PTO speed does a power harrow use?
Most modern power harrows run at 1,000 rpm, but check the plate on the gearbox before hitching up.
Related equipment
Sources
- HR 104-1004 and HRB 102-103 power harrows (Kuhn UK)
- Amazone unveils new standalone 6m folding power harrow (Farmers Weekly)
- Alexander van der Lely (CLIMMAR)
Last checked 2026-11-01