Harrows

Harrows are used for various purposes, such as preparation of seedbeds, covering of seeds, destruction of weeds and aeration of soil. Many types and sizes are in use today. The most common type is that with a zigzag frame and rigid tines.

Seed harrows are light implements with closely fitted tines, about 4 in (100 mm) long. They are used for the final preparation of seedbeds and for covering seeds after the drill. They are mounted on small tractors.

Medium tractor harrows have various functions: the preparation of seedbeds, mixing of fertilizers with soil and spring cultivation of autumn-sown corn. The wider the implement, the more important it is to have good arrangements for transport. Mounted implements up to 8 m wide may be used with tractors of 40 - 50 kw. Heavier and wider harrows for use with tractors or about 75 km may be semi-mounted. One type provides for lifting of the harrow sections to a wheeled frame, the wings of which can be manually rolled behind the centre sections.

Disc harrows cut and consolidate the soil. Two or more sets of discs are fitted on a frame which may be mounted or semi-mounted. Some heavy discs are trailed and have hydraulically operated transport wheels. Discs are supported by bearings. Disc harrows working widths vary from 1,5 to 6 m.

Adjustments of disc angle. A hand operated lever on the harrow is used to vary the cutting angle of the discs. Discs being fitted at the widest angle, the soil movement will be the greatest. When discs are set straight, they will not move the soil very much and have a consolidating effect.

Geodesy, Cartography and Land Management