Brief description

A harrow is an agricultural implement used for surface tillage. It is used after plowing to break up clods of soil, provide a finer finish, and remove weeds. It can also be used to cover seeds after sowing.

Use / Function

Surface refinement: Breaking up clods and leveling the soil surface after primary tillage (plowing).
Seedbed preparation: Creating a fine tilth suitable for planting seeds.
Weed control: Uprooting small weeds and exposing their roots to dry.
Seed covering: Dragging the soil over seeds sown on the surface.
Scale: From small hand-dragged frames to large animal or tractor-drawn implements.

Operating principle

Unlike a Plow, which cuts and turns over the soil, a harrow works by cutting into the surface and dragging through the top layer.

Mechanical Disruption: Teeth (tines) or disks penetrate the soil.
Impact and Friction: As the harrow is dragged, the soil clods hit the tines and each other, breaking into smaller pieces.
Leveling: The weight and drag of the frame smooth out the ridges left by the plow.

How to create it

1. Spike-Tooth Harrow (Basic)

Structure: A rectangular or triangular wooden frame.
Tines: Drive long iron or steel spikes (nails or forged bolts) through the cross-beams of the frame.
Hitch: Attach a chain or rope to the front of the frame for pulling.
Technical level: Basic.

2. Disk Harrow (Intermediate)

Structure: A frame with rotating steel disks set at an angle.
Operation: The disks slice and turn the soil simultaneously.
Technical level: Intermediate.

Materials needed

Frame: Wood or Iron.
Teeth/Disks: Steel or Iron for durability.
Bindings: Chain or Rope for the hitch.
Tools: Hammer, Drill Press (for metal frames), Forge (for shaping teeth).

Variants and improvements

Spike-tooth harrow: Simple teeth for leveling and seed covering.
Spring-tooth harrow: Flexible steel tines that bounce over rocks, preventing breakage.
Disk harrow: Effective for cutting through heavy crop residue.
Chain harrow: Flexible mesh of links used for pasture management and light leveling.

Limits and risks

Depth: Not suitable for primary tillage; cannot turn over heavy sod.
Rock Damage: Rigid tines can bend or break on large stones.
Compaction: Repeated use can create a “pan” layer if soil is too wet.