Types of harrows

A) Disc Harrow:

• It is a harrow, which performs the harrowing operation by means of a set, or a number of sets of rotating slat discs, each set being mounted on a common shaft.
• Disc harrow is found very suitable for hard ground, full of stalks and grasses.
• It cuts the lumps of soil, clods and roots.
• Disc are mounted on one, two or more axles which may be set at a variable angle to the line of motion.
• As the harrow is pulled ahead, the discs rotate on the ground.
• It is of two types:

I) Single action disc harrow:

• It is a harrow with two gangs placed end to end, which throw the soil in opposite directions.
• The discs are arranged in such a way that right side gang throws the soil towards right, and left side gang throws the soil towards left.

II) Double action disc harrow:

• A disc harrow consisting of two or more gangs, in which a set of one or two gangs follow behind the set of the other one or two, arranged in such a way that the front and back gangs throw the soil in opposite directions.
• It is of two types:

a) Tandem disc harrow – It is a disc harrow comprising of four gangs in which each gang can be angled in opposite direction.

b) Off-set disc harrow- It is a disc harrow with two gangs in tandem, capable of being offset to either side of the center line of pull. Two gangs are fitted one behind the other. the soil is thrown in both directions because discs of both gangs face in opposite directions.

B) Spike tooth harrow:

• It is a harrow with peg shaped teeth of diamond cross section to a rectangular frame.
• It is used to break the clod, stir the soil, uproot the weeds, level the ground, break the soil and cover the seeds.
• Its principle is to smoothen and level the soil directly after ploughing.
• This harrow mainly consists of teeth, tooth bar frame, clamps, guard, braces, levers and hooks.

C) Spring tooth harrow:

• It is a harrow with tough flexible teeth, suitable to work in hard and stony soils.
• Spring tooth harrow is fitted with springs having loops of elliptical shape.
• It is used in the soil when obstruction like stone, roots and weeds are hidden below the ground surface.
• This type pulverizes the soil and helps in killing weeds.

D) Acme harrow:

• It is a special type of harrow having curved knives.
• The front part of the knife breaks the soil and crushes the clods.
• It is good for mulching also.

E) Patela:

• It is a wooden plank used for smoothening the soil and crushing the weeds.
• It is also used for breaking clods, packing and levelling the ploughed soil and to remove the weeds.
• The cutting-edge levels and packs the soil and the curved hooks uproot and collect the weeds.

F) Triangular harrow:

• The frame is made of wood and pointed spikes are fitted in the frame.
• The teeth of the spikes are fixed and not adjustable.

G) Blade harrow (Bakhar):

• It is an implement, which consists of one or more blades attached to the beam or frame, used for shallow working of the soil with minimum soil inversion.
• It works like a sweep, which moves into top surface of the soil without inverting the soil.

H) Guntaka:

• It is used for shallow working of the soil with minimum soil inversion.
• It is mainly used to prepare the seed bed mostly in clay soils.

I) Reciprocating power harrow:

• It is a harrow fitted with rigid tynes driven by the power take off in a reciprocating, transverse or rotary motion as the machine moves forward.
• It has two horizontal oscillating arms having staggered pegs in two rows at 200 mm spacing.
• Two sets of slider crank mechanisms provide power from power tiller PTO through universal joint and bevel gear reduction box to the arms.
• A transport wheel provided in the rear of the unit ensures depth control.
• The oscillating pegs breaks the clod, pulverizes the soil to a fine tilth.