Farm Power is an essential input in agriculture for timely field operations for increasing production and productivity of the land.

Farm power is used for operating different types of machinery like tillage, planting, plant protection, harvesting and threshing machinery, and other stationary jobs like operating irrigation equipment, threshers/shellers/cleaners/ graders, etc.

SOURCES OF FARM POWER

There are different sources of farm power available in India which are classified as

• 1. Human power
• 2. Animal power
• 3. Mechanical power (Tractors + Power tillers + Oil engines)
• 4. Electrical power
• 5. Renewable energy (Biogas + Solar energy + Wind energy)

HUMAN POWER

Human power is the main source for operating small implements and tools at the farm. Stationary work like chaff cutting, lifting, water, threshing, winnowing, etc is also done by manual labour. An average man can develop maximum power of about 0.1 hp for doing farm work.

ANIMAL POWER

Power developed by an average pair of bullocks about 1 hp for usual farm work. Bullocks are employed for all types farm work in all seasons. Besides bullocks, other animals like camels, buffaloes, horses, donkeys, mules and elephants are also used at some places. The average force a draft animal can exert is nearly one-tenth of its body weight.

MECHANICAL POWER

Broadly speaking, mechanical power includes stationary oil engines, tractors, power tillers and self-propelled combines. The internal combustion engine is a good device for converting liquid fuel into useful work (mechanical work).

These engines are two types

• 1. Spark ignition engines (Petrol or Kerosene engine)
• 2. Compression ignition engines (Diesel engines)

The thermal efficiency of the diesel engine varies from 32 to 38 per cent whereas that of petrol engine varies from 25 to 32 per cent

In modern days, almost all the tractors and power tillers are operated by diesel engines. Diesel engines are used for operating irrigation pumps, flour mills, oil ghanis, cotton gins, chaff cutter, sugarcane crusher, threshers, winnowers etc.

ELECTRICAL POWER

Electrical power is used mostly in the form of electrical motors on the farms. Motor is a very useful machine for farmers. It is clean, quest and smooth running. Its maintenance and operation needs less attention and care. The operating cost remains almost constant throughout its life. Electrical power is used for water pumping, diary industry, cold storage, farm product processing, fruit industry and many similar things.

RENEWABLE ENERGY

It is the energy mainly obtained from renewable sources of energy like sun, wind, biomass etc. Biogas energy, wind energy and solar energy are used in agriculture and domestic purposes with suitable devices. Renewable energy can be used for lighting, cooking, water heating, space heating, water distillation, food processing, water pumping, and electric generation. This type of energy is inexhaustible in nature.

Usage of renewable energy sources

1. Solar energy- Solar dryers, lantern, cooker, solar still, solar refrigeration, solar lighting etc
2. Wind energy- Water pumping, electricity generation etc.
3. Biomass energy- Gasifiers to produce producer gas, pyrolysis to produce liquid fuels, Biogas etc
4. Tidal energy – electricity generation
5. Geothermal energy- Heat and electricity production

Farm Mechanization

The main concept of farm mechanization is to apply the principles of engineering and technology to do agricultural operations in a better way to increase crop yield. This includes the development, application and management of all mechanical aids for field operation, water control, material handling, storage and processing. Mechanical aids include hand tools, animal-drawn implements, power tillers, tractors, engines, electric motors, grain processing and hauling equipment.

SCOPE OF FARM MECHANIZATION

Improved irrigation facilities, introduction of high yielding varieties. use of higher doses of fertilizers and pesticides have increased the scope for greater farm mechanization Farm mechanization helps for proper utilization of basic inputs like water, seed and fertilizer, optimum placement of the seed and fertilizer, ploughing, removal of weeds, leveling of uneven land and land reclamation. If machines are used farmer and his animals are relieved of hard work. With the support of machines farmer can do his job better and quicker. He will get more leisure and devote his time to other works. He can earn better living.

BENEFITS OF FARM MECHANIZATION

• 1. Timeliness of operation
• 2. Precision of operation
• 3. Improvement of work environment.
• 4. Enhancement of safety
• 5. Reduction of drudgery of labour
• 6. Reduction of loss of crops and food products
• 7. Increased productivity of land
• 8. Increased economic return to farmer
• 9. Improved dignity of farmer
• 10. Progress and prosperity in rural areas

CONSTRAINTS IN FARM MECHANISATION 

• 1. Small land holdings
• 2. Less investing capacity of farmers
• 3. Adequate availability of draft animals
• 4. Lack of suitable farm machine for different operations
• 5. Lack of repair and servicing facilities for machines
• 6. Lack of trained man power
• 7. Lack of coordination between research organization and manufacturer
• 8. High cost of machines
• 9. Inadequate quality control of machine

ENGINES

Heat engine is a machine for converting heat, developed by burning fuel into useful work. It can be said that heat engine is equipment which generates thermal energy and transforms it into mechanical energy.

Based on combustion of fuel:

• (i) External combustion engine
• (ii) Internal combustion engine.

Based on fuel used:

• Diesel engine – Diesel is used as fuel
• Petrol engine – Petrol is used as fuel
• Gas engines – propane, butane or methane gases are used

Based ignition of fuel

• 1. Spark ignition engine (Carburetor type engines)
• 2. Compression ignition engine ( injector type engines)

External Combustion Engine

Here, the working medium, the steam, is generated in a boiler, located outside the engine and allowed in to the cylinder to operate the piston to do mechanical work.

Internal Combustion Engine

In the internal combustion engine, the combustion of fuel takes place inside the engine cylinder and heat is generated within the cylinder. This heat is added to the air inside the cylinder and thus the pressure of the air is increased tremendously. This high-pressure air moves the piston which rotates the crankshaft and thus mechanical work is done.

CONSTRUCTION OF AN IC ENGINE

I.C. engine converts the reciprocating motion of the piston into rotary motion. The piston which reciprocates in the cylinder is very close fit in the cylinder. Rings are inserted in the circumferential grooves of the piston to prevent leakage of gases from the sides of the piston.

Usually, a cylinder is bored in a cylinder block and a gasket, made of copper sheet or asbestos is inserted between the cylinder and the cylinder head to avoid ant leakage.The combustion space is provided at the top of the cylinder head where combustion takes place.

The end of the connecting rod connecting the piston is called small end. A pin called gudgeon pin or wrist pin is provided for connecting the piston and the connecting rod at the small end.  The other end of the connecting rod connecting the crank shaft is called big end.  When piston is moved up and down, the motion is transmitted to the crank shaft by the connecting rod and the crank shaft makes rotary motion.

The crankshaft rotates in main bearing which are fitted the crankcase.  A flywheel is provided at one end of the crankshaft for smoothing the uneven torque produced by the engine.  There is an oil sump at the bottom of the engine which contains lubricating oil for lubricating different parts of the engine.

Working Principle Of I.C. Engine

A mixture of fuel with correct amount of air is exploded in an engine cylinder which is closed at one end. As a result of this explosion, heat is released and this heat causes the pressure of the burning gases to increase.  This pressure forces a close fitting piston to move down the cylinder.  The movement of piston is transmitted to a crankshaft by a connecting rod so that the crankshaft rotates and turns a flywheel connected to it.

Power is taken from the rotating crank shaft to do mechanical work. To obtain continuous rotation of the crankshaft the explosion has to be repeated continuously.  Before the explosion to take place, the used gases are expelled from the cylinder, fresh charge of fuel and air are admitted in to the cylinder and the piston moved back to its starting position.  The sequences of events taking place in an engine is called the working cycle of the engine. The sequence of events taking place inside the engine are as follows

FOUR STROKE CYCLE ENGINE ( DIESEL/ PETROL ENGINE) In four stroke cycle engines the four events namely suction, compression, power and exhaust take place inside the engine cylinder. The four events are completed in four strokes of the piston (two revolutions of the crank shaft).

TWO STROKE CYCLE ENGINE (PETROL ENGINE)  In two stroke cycle engines, the whole sequence of events i.e., suction, compression, power and exhaust are completed in two strokes of the piston i.e. one revolution of the crankshaft.  There is no valve in this type of engine.  Gas movement takes place through holes called ports in the cylinder.  The crankcase of the engine is air tight in which the crankshaft rotates.

TRACTORS

Tractor is a self propelled power unit having wheels or tracks for operating agricultural implements and machines including trailers. Tractor engine is used as a prime mover for active tools and stationary farm machinery through power-take off (pto) or belt pulley.

Mechanical manipulation of soil to provide favorable condition for proper crop growth is called tillage. Soil tillage consists of breaking the compact surface of earth to a certain depth and to loosen the soil mass so as to enable the roots of the crops to penetrate and spread into the soil.

Sowing is an art of placing seeds in the soil to have good germination in the field. A perfect sowing gives

• 1. Correct amount of seed per unit area.
• 2. Correct depth of sowing
• 3. Correct spacing between row-to-row and plant to plant.
• 4. Correct seed rate

Transplanter is equipment used for transplanting mat type paddy seedlings in the main field. It is suitable for all types of paddy varieties grown by transplanting. Both manually operated and mechanically operated transplanters are available. Before transplanting, the field has to be puddled well and allowed for one or two days for consolidation of soil so that the machine can work without sinkage.

HARVESTING

The operation of cutting, picking, plucking digging or any combination of these for removing the whole crop or edible part of the crop from either under the ground or above the ground is called harvesting Mechanical actions associate with harvesting are as follows:

• 1. Slicing action with a sharp tool.
• 2. Tearing action with a rough serrated edge
• 3. Scissoring action.
• 4. High velocity impact with sharp or dull edge tool

PLANT PROPAGATION 

Most plants reproduce more of their kind through the production of seeds. This is sexual reproduction and it involves the exchange of genetic material between two parent plants. Many ornamental plants do not come "true" from seed. To increase the numbers of these plants, gardeners and horticulturists use asexual propagation. In asexual propagation, the new plants are genetically exact copies or clones of a single parent plant. The methods used in asexual propagation range from taking leaf cuttings of African violets to grafting apple cuttings onto root stocks. Fruit tree propagation is usually carried out through asexual reproduction by grafting or budding the desired variety onto a suitable rootstock.