Farm Power And Machinery (1+1)

Types of Cultivator

• Depending upon the type of power available for the implement, the cultivator can be classified as either Tractor drawn or Animal drawn.
  
• The tractor drawn cultivators are further classified as Trailed type or Mounted type.
Trailed type cultivator

• It consists of a main frame which carries a number of cross members to which tines are fitted.
  
• At the forward end of the cultivator, there is a hitch arrangement for hitching purpose. A pair of wheels is provided in the cultivator.
  
• The life is operated by both wheels simultaneously so that draft remains even and uniform.
  
• The height of the hitch is adjusted so that main frame remains horizontal over a range of depth setting.
  
• The tines in each row are spaced widely to allow free passage of the soil and trash around them.
  
• The tines in subsequent rows are staggered so that the implement can cover the entire width nicely.
  
• The depth of working is set roughly by adjusting the tine in their clamps and the final depth control is done by a screw lever.
  
• Usually the tines are damaged due to turning the implement at the headland without lifting it up. Care should be taken to lift the tines off the ground before turning.
Mounted type Cultivator

• Tractors fitted with hydraulic system operate the mounted type cultivators.
  
• A rectangular frame of angle iron is mounted on three point hydraulic linkage of the tractor.
  
• The cross members carry the tines in two staggered lines. For actual cutting the soil, different types of shovels and sweeps are used.
  
• A few important shovels and sweeps are a) Single point shovel b) Double point shovel c) Spear head shovel d) Sweep e) Half sweep f)Furrower.
• Depending upon the type of soil and crop, shovels are chosen for use on the cultivators.
  
• Usually tractor drawn cultivators are of two types, depending upon the flexibility and rigidity of tines (i) Cultivator with spring loaded tines (ii) Cultivator with rigid tines.
Cultivator with spring loaded tines

• A tine hinged to the frame and loaded with a spring so that it swings back when an obstacle is encountered, is called spring loaded tine as shown in Fig.15.1.
  
• Each of the tine of this type of cultivator is provided with two heavy coil springs pre tensioned to ensure minimum movement except when an obstacle is encountered.
  
• The springs operate, when the points strike roots or large stones by allowing the tines to ride over the obstruction, thus preventing damage.
  
• On passing over the obstruction, the tines are automatically reset and work continues without interruption.
  
• The tines are made of high carbon steel and are held in proper alignment on the main frame members.
  
• This type of cultivator is particularly recommended for soils which are embedded with stones or stumps.
  
• A pair of gauge wheel is provided on the cultivator for controlling the depth of operation.
  
• The cultivator may be fitted with 7, 9, 11, 13 tines or more depending upon the requirements.


Fig. 15.1 Tractor drawn cultivator

Cultivator with rigid tines

• Rigid tines of the cultivators are those tines which do not deflect during the work in the field.
  
• The tines are bolted between angle braces, fastened to the main bars by sturdy clamps and bolts.
  
• Spacing of the tines are changed simply by slackening the bolts and sliding the braces to the desired position.
  
• Since rigid tines are mounted on the front and rear tool bars, the spacing between the tines can be easily adjusted without getting the tines choked with stubbles of the previous crop or weed growth.
  
• A pair of gauge wheel is used for controlling the depth of operation.
Duck foot cultivator
• It is a type rigid cultivator which is used mostly for shallow ploughing, destruction of weeds and retention of moisture.
  
• It consists of steel frame and rigid tines to which sweeps are attached as shown in Plate : 15.2.
  
• The implement is attached to the tractor with three point hitch system and is controlled by hydraulic system.
  
• The sweeps are fabricated from high carbon steel.
  
• Number of sweeps can be adjusted according to requirement.
  
• Usually this cultivator is about 225 cm long; 60 cm wide with 7 sweeps.

Plate : 15.2 Duck foot cultivator