Sources Of Farm Power SS1 Agricultural Science Lesson Note

DEFINITION OF FARM POWER

Power is the rate of doing work or the expenditure of energy. Power is measured in units of joule/seconds otherwise known as watts. Farm power is the ability provided by various sources to carry on farm work. Farm power then can be defined as the energy, force and source used to carry out farming operations.

SOURCES OF FARM POWER

1. Human Power

This is the most important source of farm power without which all other sources are useless. It involves the use of man’s intellect and/or manual effort to carry out different farming activities. The great advantage of human power is man’s intelligence which means he can control the work he does.

Advantage Of Human Power

• Man’s intelligence to control the work he does.
• There is a limitation in the output of animals particularly in hot climate
• They cannot work in Tse-tse fly-infested areas.

2. Mechanization Power

This requires the use of a series of machines to carry out farm operations.  Power transmitted through engines can come directly or indirectly from electricity or the burning of fuel.

Advantages Of Mechanical Power

• It can do more work per unit of time and animals.
• Unlike human and animal power there is no fear of diseases.
•  It can be used in tsetse infected areas.

• They are the fastest and most efficient source of farm power.
• They make farm operations timely

Disadvantages Of Mechanical Power

• High capital investment is involved in the accusation of machinery. 
• Many tractors are laid off in West Africa due to a lack of spare parts.
• It is not suitable for small land holdings.
• Intensive mechanization displaces labour from the farm and can lead to unemployment. 
• It is not readily available. 

3. Electrical Power

This is power derived from electricity or a generator.  It is a neat or clean source of energy.  It is used to operate electric motors.  Motors are used to operate many modern appliances such as heaters, incubators, mixers and some power tools.  Electrical power is also measured in watts.

Advantages Of Electrical Power

• It is easy to operate
• It is efficient and it saves labor
•  It is a cheap source of farm power

• It gives quick and immediate results.
• It can be used for various services and at different times.

Disadvantages Of Electrical Power

• Electricity supply is not regular, especially in developing countries like Nigeria.
• Electrical faults may cause serious hazards.
• It cannot be widely used in the field.
• The cost of installation and maintenance is high.
• It is dangerous and fatal if carelessly handled

4. Solar Power

This is the power derived from radiation, light and heat reaching the Earth from the sun. This energy is the ultimate source of energy and it can be converted into electrical energy by installing solar panels. Solar energy is trapped into photo–voltaic cells or solar collectors which are then converted into electrical energy and stored in batteries or used directly.

Advantages Of Solar Power

• Solar power is inexhaustible. 
• Solar energy can be used to dry crops, power machines and generate electricity.
• Solar energy technology is environmentally friendly.

• It is readily available.
• Solar panels have a long life span.

Disadvantages Of Solar Power

• It requires a lot of technical know-how. 
• It is only available during the day.
•  Its provision cannot be controlled.
• It cannot be adjusted on readily stored. 
• Excess of it can cause transpiration and evaporation. 

5. Wind Power

This is the power generated by wind movement. Wind power is made possible through the use of windmills that help to pump water out of the boreholes or generate electricity.

A water-pumping windmill in Spring, Arizona, provides water for agricultural use. The blades, or sails, are mounted at an oblique angle on the horizontal shaft. The fantail rudder steers the bladed wheel into the wind to maximize the windmill’s efficiency.

Advantages Of Wind Power

• Wind can be harnessed to drive boats, power grinders and operate water pumps. 
• It can be used for drying farm produce.
• It is cheap and available everywhere.

• It is used in winnowing, i.e. separation of chaff from grains.
• It can serve as an alternative to electrical power.

Disadvantages Of Wind Power

• The supply of wind is sporadic and uncertain. 
• A large windmill often proves to be very expensive for the energy it produces.
• It cannot be stored.
• It is difficult to control. 
• It is limited to certain farm operations.

6. Water Power

This is the power derived from water flowing in rivers, oceans, dams etc.  It is used in hydroelectric stations to drive the turbines.  A turbine is a rotating engine with its blade driven by water.

Advantages Of Water Power

• A steady and uninterrupted flow of water can be made to turn turbines or water wheels to generate electrical energy.
• It is used in the transportation of farm goods.
•  It can be used to process farm produce.

• It is needed in seed germination and normal growth of crops
• It is needed in the process of photosynthesis by plants.

Disadvantages Of Water Power

• Low level of water can hinder electricity output. 
• It is not available in all areas.
• It could be destructive if not carefully handled.
• Supply is affected by weather.
• It costs a huge sum of money to set up and maintain

7. Biogas

A method of generating power by making use of farm wastes, especially animal dung, urine etc collected and processed to produce methane gas.

Advantages Of Biogas

• A cheap source of power.
• It can be used to generate heat for brooding chicks.
• It can be used for cooking and drying.

• It can also be harnessed to generate electrical energy.
• It can easily be controlled.

Disadvantages Of Biogas

• It requires expertise which may not be easily available.
• It is expensive to set up and maintain.
•  It is not a common source of power.

• It is restricted to where animals are reared on a commercial basis.
• If not properly handled, it can lead to fire incidents.

ASSIGNMENT 

1. What is farm power?
2. What are the sources of farm power?
3. State three advantages and disadvantages each of:

• Wind power 
• Water power 
• Solar power 
• Electrical power 
• Animal power
• Biogas

4. State three uses of biogas

5. List three sources of hydroelectric power