Tractor Drawn Harrows by Dhivyadharshini

Tractor drawn harrows

1. FMP211-FARM MACHINERYAND POWER [1+1] TRACTOR DRAWN HARROWS M.DHIVYADHARSHINI 2021022023

2. INTRODUCTION Tractor Drawn Harrows comes under Secondary Tillage Implements. Different types of implements like cultivators, harrows, planks and rollers are used for secondary tillage. In agriculture, a harrow is a farm implement used for surface tillage. It is used after ploughing for breaking up and smoothing out the surface of the soil. The purpose of harrowing is to break up clods and to provide a soil structure, called tilth, that is suitable for planting seeds.

3. HARROWS Harrow is a secondary tillage implement used for a variety of jobs in crop cultivation . TYPES OF HARROW The disc harrow blade harrow spike tooth harrow spring tooth harrow triangular harrow acme harrow

4. DISC HARROW Disc harrow is found very suitable for hard ground, full of stalks and grasses. It cuts the lumps of soil, clods and roots. Discs 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. Depending upon the disc arrangements, Disc harrows are divided into two classes a) Single action b) Double action

5. DOUBLE ACTION DISC HARROW TANDEM DISC HARROW OFF-SET DISC HARROW

6. Disc : It is a circular concave disc which cuts and inverts the soil. plain disc , cut away disc Gang: Each set of discs that are mounted on a common shaft is called the gang. Gang bolt or arbor bolt: It is a long heavy square headed bolt Gang angle .- The angle between the axis of the gang bolt and the direction of travel is called the gang angle. Gang control lever: This lever is used to change the gang angle of the gangs which in turn alters the width of operation.

7. Spool or spacer: The flanged tube, mounted on the gang bolt between every two discs to prevent the lateral movement of the disc on the shaft is called the `spool’ Bearing : Bearing is essential for frictionless rotation of the gang. Transport wheel : In trailing type disc harrows, transport wheels are provided for transport of the harrow on roads without damage to the edges of the discs . Scraper : It removes the soil that may stick to the concave side of the disc while working and thus prevents clogging of the discs. Weight box : A box like frame is provided on the main frame of the harrow for putting additional weight on the implement to increase the penetration of the disc in the soil.

8. SPIKE TOOTH HARROW   It is a harrow with pegs shaped teeth of diamond cross section to a rectangular frame as working part fitted in a rigid articulated or flexible frame The harrow is an excellent tool for pre-emergence cultivation to break the rain-firmed crust and small weeds. It generally works about 2 inches of depth. Spike tooth harrows may be of rigid type and flexible type. SPRING TOOTH HARROW Spring tooth harrow is also called as quack grass, and Bermuda grass eradicator. Spring tooth harrow is fitted with springs having loops of elliptical shape. It gives a spring action in working condition. It is used in the soil when obstruction Spring tooth harrow like stone, roots and weeds are hidden below the ground surface.

9. ACME HARROW Also known as blade harrow; curved knife-tooth harrow; pulverizers .   It is a special type of harrow having curved knives. It is also called as knife harrow. The front part of the knife breaks the soil and crushes the clods . This harrow obtains a good pulverization. It is good for mulching also PATELA It is a wooden plank used for smoothening the soil and crushing the weeds

10. TRIANGULAR HARROW It is a spike tooth harrow with triangular frame . The frame is made of wood and pointed spikes are fitted in the frame. The teeth of the spikes are fixed and not adjustable BLADE HARROW (BAKHAR OR GUNTAKA) It is a spike tooth harrow with triangular frame The frame is made of wood and pointed spikes are fitted in the frame. The teeth of the spikes are fixed and not adjustable Animal drawn implement used to prepare seedbeds in clayey soils and soil mulch for soil moisture conservation

11. Advantages Harrow can break up surface crusts and soil clods. You can use a harrow for cultivating the land with great precision. It is helpful for improving the aeration and surface uniformity of the land. You can eliminate the already emerged weeds. Also, you can use it in any type of soil. Moreover, it helps in pulverising the soil

12. Disadvantages Harrowing the soil requires  regular proper training  and is  time-consuming . Harrowing excessively moist or excessively dry soil can  disrupt the properties of soil  which makes it problematic for planting. Harrowing can be a  host for insects and plant infections  to grow and blossom freely.