• Farm power is any form of energy used in the farm to do work.             .

Sources of Farm Power

Human Power

  • Performs light tasks.
  • Quality of work produced is variable.
  • Takes a long time to complete a task.

Animal Power

  • Done by draught animals such as camels, donkeys, horses and elephants.
  • Used in land preparation and transportation.


  • Slow.
  • Animals are liable to sickness and get tired.
  • Need enough food.

Wind Power

  • To pump water from boreholes.
  • To winnow crops such as beans, finger millet and rice.
  • Generate electricity.


  • Not easy to control and may not be available when needed.

Water Power

  • Irrigation.
  • Grinding mills (to grind maize grains).


  • Difficult to use in the farm because it is not easy to control.


This includes:

  • wood or charcoal
  • biogas power.

Charcoal/Wood Fuel Energy


  • Provides heat for boiling water and cooking.
  • Dehydrating of some crops.
  • Curing of tobacco.


  • Exhaustible.
  • It cannot be used directly in some farm operations.
  • Large quantities are required.
  • They are bulky hence difficult to transport.



  • Provides heat and light for cooking, boiling water and lighting.
  • Produces electricity.


  • Only possible where there are animals under zero grazing unit.
  • It is labour-consuming.
  • Large quantities of dung are required.
  • Cannot be used directly in some farm operations.

Fossil Fuels

These include:

  • coal,
  • petroleum oils
  • natural gas.


  • Petrol or diesel is burned in internal combustion engines to produce power.
  • Kerosene is the main source of power to light rural homes.
  • Natural gas is used for cooking, heating and lighting.

Electrical Power

It includes:

  • hydro-electrical power (HEP),
  • geothermal,
  • nuclear
  • power stored in batteries.
  • Nuclear energy is a potential source of power which has not yet been used in the farms.

Uses of Electrical Power

  • Runs stationary machines such as milling machines, grinding mills, cooling machines and water pumps.
  • Supplies heat and light for operations of brooders.


  • Cannot be used directly in some farm operations.
  • Lack of electricity in the rural areas.
  • Power failures can lead to high losses.
  • It is costly to install and maintain.


Solar Energy

Energy obtained from the sun.


  • Provides heat and light.
  • Used by all the plants in photosynthesis.
  • Dehydrating crops such as vegetables, maize grains, beans and hay.
  • Boils water which drives turbines to produce power for minor uses.


  • Low concentration of energy on cloudy d
  • Expensive In collecting and concentrating equipment.
  • Cannot be used directly in some farm operation
  • Requires skilled labour to install and maintain.


  • The tractor has an internal combustion engine which burns petrol or diesel to produce power.
  • This power is then passed to the gear box from where it is transmitted in various ways.
  • The common tractor engine is a four stroke cycle engine.

The four strokes are:

  • Induction stroke.
  • Compression stroke.
  • Power stroke.
  • Exhaust stroke.

Induction Stroke

  • Piston moves down.
  • Inlet valve opens.
  • Fuel and air get into the cylinder.

Compression Stroke

  • Inlet valve is closed.
  • Piston moves up the cylinder.
  • Fuel-air mixture is compressed.

Power Stroke

  • A spark is produced at spark plug, igniting the fuel-air mixture.
  • The increased pressure forces the piston down the cylinder.

Exhaust Stroke

  • Exhaust valve opens.
  • Piston moves up the cylinder.
  • Burned fuel-air mixture expelled.


Advantages of the Four Stroke Engines

  • Produce high power which can do heavy farm work.
  • Have efficient fuel and oil utilization.
  • Perform a wide range of farm operations.
  • Are effectively cooled with water thus allowing the production of large engine size.
  • Exhaust gasses are effectively expelled from the cylinders.



  • Are expensive to buy and maintain
  • Their use is limited in some areas;
  • Tractor can only be used on flat or gently sloping areas
  • Require skilled personnel and support services


The Two Stroke Engines

  • Found in small machines such as mowers, motor bikes, and water pumps which do light jobs in the farm.
  • All the cycles are completed in two strokes of the piston.

        These strokes are;

Induction and compression stroke

  • The piston is at the bottom
  • Piston moves up uncovering the inlet port
  • Fuel-air mixure is drawn in
  • Ignition occurs when the piston reaches the top
  • Piston is forced downward compressing the mixture in the crank.

Power and exhaust stroke

  • The piston is at the top
  • Ignited gases produce pressure which force the piston downwards
  • The piston covers the inlet port and traps fresh fuel-air mixture in the crank case
  • Piston moves further down to uncover the exhaust port
  • Fuel-air mixture transferred from the crankcase to the combustion chamber.

What Advantages of two stroke engine?

  • Cheap to buy and easy to maintain
  • Economical in fuel consumption
  • Can be used in a wide  range of farmland, including hilly areas
  • Can do small tasks in the farm which would be un-economical to do using the four stroke engine.

What disadvantages of two stroke engine?

  • They produce less power hence cannot be used for heavy duties.
  • They are inefficient in burning fuel to produce power.
  • They are air cooled thus limiting the size of the engine.

Systems of a Tractor

The modern tractor has the following systems:

  • The fuel system.
  • Electrical system
  • Ignition system
  • Cooling system
  • Power transmission system.

The Fuel System

Supplies fuel to the engine.

Categorized into two types depending on the fuel used.

These are:

  • The petrol fuel system.
  • The diesel fuel system

The Petrol Fuel System

Consists of:

Fuel tank – storage of fuel.

Fuel filter – removes foreign particles from the fuel.


  • atomises fuel into spray.
  • introduces fuel-air mixture into the engines.
  • Regulates fuel-air into suitable proportion

Fuel pump – forces fuel into the carburettor.

Delivery pipe – connects all the devices.



  • Cleaning the carburettor regularly.
  • Cleaning the fuel filter in petrol.
  • Cleaning the hole in the fuel tank cap.

The Diesel Fuel System

Consists of:

  • Fuel tank – storage of fuel.
  • Fuel injection pump – pumps diesel through injection nozzles and breaks into fine spray.
  • Fuel filters – remove foreign particles from the fuel.
  • Delivery pipes – connect the various devices.


  • Replacing the fuel filter.
  • Bleeding in case air is trapped in the system.
  • Cleaning the sediment bowl regularly.

Electrical System

Consists of the following:


  • Converts chemical energy into electrical energy.
  • Stores electrical energy produced by the running

Ignition circuit – provide the electrical required by the spark plugs.

current that produces a spark in the engine.

Generator circuit – provide the electrical current that starts the engine.

Lighting circuit – supply the electrical current required for the lighting system.

Starter motor circuit – starts the engine.


Care and Maintenance of a Tractor Battery

  • The level of electrolyte should be kept just above the plate by topping with distilled water.
  • Corroded terminals should be scrapped clean and smeared with grease.
  • The battery should be tightly fixed in a box to avoid spillage and damage.
  • The battery should be fitted correctly on the tractor.
  • The battery should be charged regularly and periodically.
  • In case of long storage the battery contents should be kept upside down.
  • The generator fan belt should always be functional to ensure the battery is always charged.


 Ignition System

Consists of:

Ignition change the low voltage from the battery to high voltage current  required by the spark plugs.

Condenser – absorbs the self-induced current in the primary circuit.

  • stores current for a short time.
  • passes electric current to the distribut

Distributor – distributes the high voltage current to the spark plugs.

Contact breaker – Interrupts the normal flow of current in the primary circuit.

State the Maintenance practices carried on  the Ignition System

  • The carbon deposits on the spark plug electrodes should be removed.
  • The spark plugs whose electrodes are worn out should be replaced.
  • The contact breaker points should be cleaned.
  • The breaker points should be adjusted so that they lie between O.30mm and 0.50mm.
  • The condenser should be replaced regularly.
  • The ignition systems should always be kept dry.
  • Ignition wires with poor insulation should be replaced.

Cooling System

  • The cooling system aims at preventing the engine from overheating which would cause piston zeisure in the cylinder.
  • Some tractor engines are cooled by air while others are cooled by water.

State the Characteristics of Air Cooled Engines

  • They are simple in construction.
  • They have fins and a fan blade which assists the circulation.
  • They are light in weight for they have no radiators and water jack


  • They get hot quickly and use heavy lubricating oil.
  • The cooling is not adequate under all conditions especially when carrying heavy load

Water Cooled Systems

  • It consists of the radiator, water jackets, water hoses, water pump, thermostat and a fanning mechanism.
  • Water is used to absorb heat from the engine block at a reasonable rate.

 Care and Maintenance of Water Cooling system

  • The water pumps should be lubricated regularly.
  • Clean water should be used in the radiator and trash removed from the fins.
  • All pipes should be fitted tightly to avoid blockage.
  • The radiator should be filled with clean water before starting the day’s work.
  • Fan belt tension should be checked regularly and if too tight or too loose should be adjusted accordingly.

Lubrication System

  • This system is aimed at supplying oil to all parts of the engine where friction is likely to occur.

Importance of Lubrication system

  • It helps to increase the efficiency of the machine and reduces the rate of wear and tear of moving parts.
  • It reduces the heat created by the rubbing surfaces and acts as a seal between them.
  • It acts as a cleaning agent because it washes off all the dust, dirt, soot and metal chippings from the oil paths to the sump.

Types of Lubrication Systems;

  • Splash feed type
  • Force feed type
  • Oil mist type

Types of Lubricants

  • SAE 10 – This is thin engine oil which gives little protection when heated.
  • SAE 50 – This is thicker engine oil which is recommended for protecting the bearings.
  • SAE 90 – 100 – These are transmission oils which are recommended for clutch, gear box, wheel lubrication and ball bearings.

      Note: SAE Society of Automobile Engines.

Care and Maintenance of Lubrication Systems

  • Old or contaminated oil should not be used for lubrication.
  • Oil should be drained when still hot to avoid sticking on the walls of the sump.
  • The oil filters should be replaced when necessary.
  • The correct type of oil should be used as per the manufacturers’ instructions.

Power Transmission System

  • The function of this system is to transfer power from the tractor engine to the drive shaft, the wheel axle, the power take off shaft and the hydraulic system.
  • The system consists of the clutch, gear box, differential and the final drive.

The power transmitted from the engine is made available for use through the following:

  • The propeller shaft – it connects the gear box to the differential.
  • The power take off shaft (PTO shaft)­ -It is located at the rear part of the tractor and rotates at the same speed as the crankshaft of the engine.
  • Hydraulic system – it is operated by the use of a lever near the drivers seat.
  •  It is connected to the 3-point linkage and helps to lower or raise implements mounted on the 3-point linkages such as ploughs, mowers, planters and sprayers.
  • Draw bar –
  • It is a one-point linkage at the rear part of the tract
  • It serves for the attachment of trailed implements that can be used during harrowing, transportation or rolling.

Tractor Servicing

  • The aim of tractor servicing is to keep the tractor in good and efficient working conditions.
  • Tractor servicing is either;
  • short
  • long term.

List the Short Term Tractor Servicing

 It includes:

  • Checking the engine oil daily by use of a dip stick.
  • If the oil level is low, it should be added.
  • The fuel level should be checked at the start of every day’s work and added if necessary.
  • Water level in the radiator should be checked and if possible topped up.
  • The level of the electrolyte should be checked daily and topped up with distilled water accordingly.
  • Nuts and bolts should be tightened every day.
  • Lost nuts and bolts should be replaced before the day’s work.
  • Grease should be applied by use of grease gun through the nipples.
  • Large sediments from the sediments bowl should be removed.
  • The tyre pressure should be checked daily before the day’s work.
  • The fan belt tension should be checked to ensure that it deflects between 1.9cm and 2.5cm when pushed.
  • The brake shaft bearing should be greased.
  • The brake fluid level is maintained at the recommended level.

Long Term Services

  • The engine oil should be drained completely from the oil sump and replaced with new oil.
  • The gear box oil should be checked and refilled as recommended.
  • The oil in the differential should be replaced as recommended.
  • The linkage and the pulley attachment should be greased.
  • The pulley oil level should be checked and added if need be.
  • The dirty oil should be removed and replaced with clean one.


Farm Machinery

Tractor Drawn Implements

  • These are implements which are attached to the tractor during opera

State the two categories. Tractor Drawn Implements

Onepoint hitch implements ;

  • Are attached to the tractor at only one point that is, the draw bar.
  • They include all trailed implements such as the trailers, heavy harrows, planters and roller

Three point hitch implements;

  • Are implements attached to the tractor at three points that is, the top linkage point and two lower linkage point
  • They are operated by the hydraulic system.
  • They include ploughs, most harrows, sub­soiler, planters, mower, ridgers, sprayers and rotavators.



  • They are one-point hitch implements.
  • They are used for transportation of goods.
  • Small ones have two wheels while big ones have four wheels.



  • All the moving parts should be lubricated.
  • Tyre pressure should be adjusted to the correct pressure.
  • Worn out tyres should be replaced.
  • Loose nuts and bolts should be tightened, worn-out ones should be replaced.
  • The implements should be kept under a shed during long storage.



  • They are primary tillage implements.
  • The common type of ploughs include:
  • Disc plough
  • Mould board ploughs.

Disc ploughs

  • It is made up of heavy steel concave discs of 60-70cm diameter.

Parts and Functions of a disc plough

The hitchmast:

  • Is an attachment for the three point hitch.
  • Made up of two side links and a top link.
  • These are parts connected to hydraulic system of a tractor for lifting and pulling.
  • The beam: Supports all other parts. It also adds weight for better penetrati
  • Depth wheel:
    • Used when driving on highway,
    • it also controls the depth of plou
    • May not be present in all disc ploughs.
  • The standard or leg: Connects the discs to the beam.
  • The hub: Allows the discs to rotate smoothly hence does the cutting of furrow slices.
  • The scrapers: Remove the trash and mud or soil which cling to the discs,
  • Disc blades: Cut and invert the furrow slice
  • Rear furrow wheel: Controls the depth of digging and stabilises the discs.


Adjustment                .

  • The cutting angle should be adjusted at 35° – 50° from the I ine of travel.

Achieved by pivoting the beam or the standard.

  • Depth of digging: This is corrected by changing the height of depth wheel or adjusting hydraulic system and adding weight

Care and Maintenance of Disc Plough

  • Check for loose nuts and bolts and replace them.
  • Sharpen the disc blades if blunt.
  • Lubricate the rotating parts by use of oil/grease to reduce friction.
  • Paint the exposed parts for example the beam/framework.
  • Clean the implement at the end of each day’s work before storage.
  • Store the implements in a shed.
  • The unpainted parts should be coated with old engine oil to prevent rust.

Uses of a Disc Plough

      Used in areas with the following conditions:

  • Virgin land with many obstacles.
  • Land with too much trash or tall vegeta
  • Opening up pasture land.

Mouldboard ploughs

  • This primary tillage implement is suited in areas without obstacles such as stones, tree stumps, and roots.
  • It gives a uniform depth of ploughing.

Parts and Functions Mouldboard ploughs

  • Share: This makes the horizontal cut and starts the turning of the furrow slices.
  • Mouldboard: Continues the turning of the furrow slices and pulverizes the soil.
  • Disc coulter: Makes a vertical cut in the soil to separate the furrow slice from the un-ploughed land.
  • Skim coulter: Removes any trash from between the furrow slices.
  • Frog: It is the part where the share, mould board and the landside are attach
  • Landside: Stabilizes the plough and absorbs the side forces created when furrow is turned.
  • Shin: Leading edge of a mouldboard.
  • Knife coulter: Is a vertical knife which cuts trash and earth ahead of the share.


Care and Maintenance

  • Lubricate the rolling parts for example wheel bearings and disc coulter bearings.
  • Paint scratched parts of the plough.
  • Sharpen the share or replace if worn out.
  • Check all loose nuts and bolts and replace where necessary.
  • Clean the implement after each day’s work to remove soil, mud and trash.
  • For long storage, keep under a shed and apply lubricants.



  • Controlled by raising or lowering the depth wheel.
  • Controlled by hydraulic control lever setting.

Pitch: controlled by altering the length of the top li

Front furrow width: Controlled by cross shaft adjustment lever or by rotating the cross shaft crank.

Lateral levelling: Controlled by tractor lift rod.


  • They are secondary cultivation implements.
  • There are different types of harrows.
  • The common ones are:

disc, Harrows

spring tine Harrows

spike tooth harrows.


Disc Harrows

  • It comprises of a set of gangs with concave discs.


  • Mixing the soil particles.
  • Levelling the seedbed by breaking large
  • lumps of soil.
  • Killing weeds.


Disk harrows can be classified according to the arrangement of the gangs such a;

  • s tandem,
  • double tandem
  • offset tandem.

Depth Adjustment

  • Adding weights on the harrows.
  • Use of hydraulic force.
  • Use of light or heavy harrows.
  • Use of regulating wheels.

Care and Maintenance

  • Check for loose nuts and bolts daily.
  • Lubricate the shafts and bearings.
  • Clean and oil before storage.

Spring Tine Harrow

  • Is made up of flat and curved tines which act as springs.


  • Levels and smoothens the seedbed.
  • Breaks the soil clods.
  • Mixes trash and soil thus preventing wind erosion.
  •  Aerates the soil.


  • Depth is controlled by the horizontal connecting link and depth wheel.
  • For individual tine, use crossbar and loosening the screws.

Care and Maintenance

  • Check for loose nuts and bolts and tighten them if necessary.
  • Clean after use.
  • Oil the lever mechanism.


 Spike Tooth Harrows

  • Consists of a metal framework with rigid metal spikes which break up the soil by vigorously hitting large lumps of soils as it is pulled through the soil.


  • It smoothens and compacts the soil.
  • It breaks big lumps of soil into small particles.
  • Can be used for cultivating small crops if well set.


  • Heavy and require high horse power to pull.
  • Ploughing depth of 51-90cm.



  • Break up compacted soil.
  • Break up the hardpan.

Care and Maintenance

  • Clean it after use
  • Check the point and if worn out, replace it.
  • Oil when not in use.


  • It is double mould board plough used to make ridges and furrow
  • It is used to prevent water logging and draining through furrows for easy harvesting of root crops.



  • This is an equipment used to compact the soil gently especially where tiny seeds are to be planted.

Rotavators: (Rotary cultivators)

  • Work on the principles of high speed of revolving flail blades which beat and cut the soil together with trash.
  • It is an equipment for both primary and secondary tillage operations.
  • It is driven by the P.T.O. shaft of a tractor.


  • Breaks up large soil particles into small ones.
  • Mixes the vegetation and the soil.
  • Achieves two operations in one pass.


  • Forward speed of the tractor gives a fine tilth of the seedbed done through the gearbox.
  • Depth of work done by control of depth wheel.
  • Slip clutch may break in case the knives come across obstructions



  • Cutting grass for hay or silage making,
  • cutting overgrown grass
  • clearing the field.

Reciprocating Mower

Parts and Functions

  • Swath stick: Keeps the cut crop falling correctly.
  • Swath board: To remove the cut crop.
  • Shoe: Has a runner to absorb the weight and wear.
  • Cutter bar: Is a flat bar which guides the fingers.
  • Wear plate: Counteracts downward force and holds the knives.


  • To adjust knife register by moving the whole bar away or towards the yoke.
  • Knife lead: The outer shoe should be adjusted to be outer than the inner shoe by 4cm.


  • Check for loose nuts and bolts and tighten where necessary.
  • Keep knife section sharp.
  • Lubricate the knife parts.
  • Check knife to ledger plate cup for best cutting.
  • Keep all the parts tight.

Rotary Mowers

  • Cutting edge consists of two blades fitted opposite to each other on horizontal disc.
  • The cutting blades swing round at high speed horizontally to the ground hence cutting is effected.

Adjustment and Maintenance

  • Blades should be sharp.
  • Guards to be fitted around the blades to protect the operator from flying objects.
  • Lubricate the P.T.O. shafts.
  • Check the gear-box oil regularly and fill to the right level if necessary.


  • They are machines used for sowing seeds.
  • There are two types:
  • Row crop planters.
  • Seed drills.


Functions of the Planters

  • Meter the seed and fertilizers from seed and fertilizer
  • Open the seed furrow.
  • Deposit the seed in the furrow through the delivery tubes.
  • Cover the seed


Functions of Parts of a Seed Plate

  • Filler plate: gives proper seed depth.
  • False ring: allows the seed to fall from the seed plate into the boot.
  • Knockout pawl: pushes the seeds out of the cell by the roller action.
  • Cut-off pawl: prevents more than one seed remaining in a plate cell.
  • Cells: shaped holes to hold the seed.



  • Adjust the coulters depth for the right crop.
  • Fix the right seed plate.
  • Place the planter in the level position.
  • All the shafts should be free to turn.


Care and Maintenance

  • Check all loose nuts, bolts and tighten them.
  • Clean and oil the planter after use.
  • Grease the drive sprockets regularly.



  • The grain drill sows grains of wheat, barley, oats, peas, beans and alfalfa seeds.

Parts that can be adjusted to change the sowing rate;

  • Select the side of the feed wheel recommended on the drill charts for the seed-rate.
  • Change the speed of the wheels by changing the gears or sprockets or both.
  • Change the position of the feed gate in the cup.
  • Use reducers below the feed wheel.

Care and Maintenance

  • Keep seed and fertilizer hoppers dry and clean after each day’s work.
  • Check the drive shaft and lubricate them.
  • Paint the parts for example fertilizer
  • hopper to be shiny


Combine Harvester


  • Harvesting cereal crops for example maize, wheat and barley.

It is designed to do the following:

  • Cutting
  • Threshin
  • Winnowing
  • Bagging

Parts of a Combine Harvester

  • Cutter bar – cuts the grain head.
  • Pick up reel- direct crop into the cutter bar,
  • Elevator – channels the cut grain to the threshing drum.
  • Winnowing ran – fans trash up onto a straw walker and directs it out of the combine harvester.
  • Delivery tube – delivers the clean .grains into a collecting tank from where it is bagged.

Maintenance of a Combine Harvester

  • Loose nuts and bolts should be tightened.
  • Remove all foreign materials stuck in the machine at the end of the day’s work.


  • They are used for harvesting tuber crops and for making furrows or ridges.


  • Lubricate the moving parts.
  • Clean the implement after use.
  • Store under a shed.
  • Repair or replace worn-out or broken parts.
  • Loose nuts and bolts should be tightened.
  • Unpainted parts should be oiled during long storage.
  • Shares should be sharpened if blunt.


  • They are tractor mounted and operated by power from the P.T.O. shaft .
  • Used for harvesting forage crops such as Napier grass, sorghum and maize.


  • Tighten loose nuts and bolts.
  • Lubricate moving parts.
  • Store in a shed.
  • Clean after the day’s work.
  • Repair/replace worn out or broken parts.
  • Unpainted parts should be oiled to prevent rust.


Maize Shellers

  • These are stationary implements which are either hand or tractor driven.
  • They consist of. a rotating disc which shell maize grains from cobs.



  • Greasing moving parts.
  • Removing any stuck maize cobs.
  • Repair or replace worn out or broken parts.
  • Store in a shed.

Animal Drawn Implements

Ox Plough

  • Ox-plough is a simple type of a mouldboard plough which is pulled by a pair of oxen, donkeys or camels.

Explain the functions of the following parts of an ox-plough

  • Main beam – It is the main component onto which all the other parts are attached.
  • Mouldboard – It inverts the cut furrow slice upside down.
  • Plough share -It cuts the furrow slices.
  • Land wheel- It regulates the depth of plough.
  • Draft rod It is on this rod that a chain is connected on which a yoke is linked.
  • It forms the draught mechanism of the plough.

What are the Advantages of an Ox-Plough Over Tractor­ Drawn Plough ?

  • Less skill is required to operate it.
  • Useful where tractors cannot be used for example steep slopes.
  • Cheap to buy and maintain.

 What are the disadvantages of an Ox-Plough Over Tractor­ Drawn Plough ?

  • Much time is wasted in training oxen.
  • Tedious and laborious to the driver of the animals and the controller of the implement.
  • Animals can be sick or in poor physical state.
  • Extra land is required as grazing fields for the oxen.



  • Depth of plough is controlled by the land wheel and draft rod


Care and Maintenance

  • Sharpen or replacing of the worn out share
  • Replacement of worn out parts such as hooks and draw bar assembly.
  • Oiling the shiny parts e.g  mouldboard
  • Wash off the soil after use.
  • Paint the handles, beam and braces to prevent rusting.


Ox-Drawn Cart

  • These are small carriages harnessed to the animals by a yoke
  • The small carts have only two wheels bigger ones have four.
  • They are pulled by animals in singles or in pairs
  • Carts are used for transport.


  • Moving parts should be oiled
  • The yoke should be repaired when worn out or replaced if not repaired
  • Tyre pressure should be checked and adjusted accordingly
  • Repair other damages on the cart.
(Visited 393 times, 1 visits today)
Share this:

Written by