Farm Power and Machinery, SOI 3102
Introduction
Farm Power and Machinery refer to the study of farm equipment, tools, implements and the various sources of power to energise the machineries for easy, successful and efficient farm operations. Thus, power is needed on farm for stationary (Threshing, drying, water pumping, etc) or mobile operations (ploughing, harrowing, transportation, weeding, etc). It should be noted that equipments and machineries are needed in each of the farm operations from land clearing to transportation. The sequence of the typical farm operation for the crop productions starts with land clearing, land development, tillage, planting, crop protection, harvesting, threshing, winnowing, grading and cleaning and then transportation. There are categories of machineries in each of the farm operation and each machine/equipment has to be energized to function.
Sources of farm power
The power for
early farming operations was primarily human labor. Later, draft animals were
used as the source of power. Horses, water buffalo, oxen, camels, and even
elephants were used as power sources. Mechanical power became the primary
source with the development of steam engines in 1858. In 1889 the first tractor
with an internal combustion engine was built. Tractors powered by internal
combustion engines were lighter and more powerful than steam-powered tractors.
In the 1930s the high compression diesel engine was adopted for tractors and
became very popular. Today's modern tractor is a very sophisticated machine
with hydrostatic drive, electro-hydraulic servos to control draft force and the
operating depth, and an ergonomically designed, climate-controlled operator's
station. Developments of technologies such as global positioning systems (GPS)
and geo-spatial information systems (GIS) have led to the development of what
is commonly known as precision agriculture in which soil variability and
fertility data are stored in an on-board computer that controls the application
rate of chemicals such as fertilizers, pesticides, and herbicides.
Farm power
refers to energy to operate farm equipment for farming operations such as land
preparation activation, harvesting, processing, handling, pumping and
transportation. Generally, agricultural operations can broadly be classified
into two. They are tractive operation
such as tillage, planting, needing, harvesting and transportation, and (ii)
stationary operation such as threshing, winnowing drying grinding, silage
cutting, water lifting, etc. These operations are done by different sources of
power, namely human, animal, internal combustion engines, wind, electricity,
solar, water etc.
Human or Manual Power
Human power
is one of the most important sources of power especially in developing
countries. On an average a farm worker
can develop 0.1 horse power or 0.075kw. This varies with environmental
conditions and the type of food intake. Generally, men can serve as the main
source of power or as a control device. This depends on the degree of
mechanization.
Animal Power
Animal
power is still widely used in many developing countries of the world. It is the
cheapest source of energy. It is appropriate and sufficient to most needs in
many farming situations. Among the draught animals oxen or bullock, camels and
buffaloes are extensively used for draft purpose. Others are donkeys and
horses. Animal power may be used for both stationary and mobile operations.
Harnesses and yokes are used to hitch various types of implements and equipment
to the animal. The power output is highly variable. It is dependent on size,
age, food intake, breed, and training, duration of working and method of
harnessing. Generally animals can provide a pull of about 10-20 percent of
their body weight for sustained periods. The effective daily working period
vary from 3.5 to 5.5 hours depending on the type of the animal.
Wind power
Wind power
is used for water pumping, electricity generation, etc. A 5 m/s wind speed can
pump out 180 l/h from a depth of 10 m. The most important thing in tapping wind
power is the construction of the windmill and placing it across the wind
direction to move the blades.
Solar Power
Solar power
is the power tapped from the sunlight. Tropical countries are blessed with
abundant solar energy. Nigeria for instance receives about 490 W/m2/day. Thus,
Nigeria has plenty of potential for the development of solar energy. Solar
energy can be used for processing of fruits, vegetables and for drying of
crops. Another application is in solar operated pumps.
Internal Combustion Engines
These can
be used on the farm for a wide range of operations. They are devices to release
the available energy in fuel like petrol, kerosene, diesel and similar
petroleum products. They can be called energy convertor, in that they liberate
the heat energy in the fuel and convert it into usable mechanical energy.
Examples of internal combustion engines as use in the farm are tractors and
small engines for stationary operations.
Electric Power
Electricity
is the most efficient and clean source of power used on the farms. It is used
for heating; refrigeration; water supply; and stationary operations such as
threshing, grinding, drying, electric motors, which convert the electric power
into mechanic power, are driven by electricity.
Internal Combustion Engine
In IC
engine, combustion takes place within the engine itself. A mixture of air and
fuel in correct proportion is introduced into the engine for combustion to take
place through burning inside the engine to produce high energy gas which is
used to carry out useful work through suitable mechanism with the components of
IC.
Tractors
Tractors
have large and powerful diesel engines and, gearbox, which converts the
high-speed revolutions of the mighty diesel engine into much lower-speed
revolutions of the wheels, increasing the force the tractor can use for pulling
things at the same time
Tractors
were originally designed to replace working animals such as oxen and horses,
which people have been using to pull carts and plows since ancient times. One
of the pioneers of modern tractors, American industrialist Henry Ford, got at
least part of his inspiration from a simple determination to come up with
something better than the horse for doing heavy farm work
Before tractors came along,
horses made life much easier for farmers, but all they could really do was pull
things. Because early tractors were merely replacements for horses, pulling
things was pretty much all they could do as well. Those early tractors were
fueled by coal and known as steam traction engines. They looked like small
steam locomotives, with large, sturdy metal wheels capable of rolling down
roads, and they first appeared toward the end of the 19th century. Catching
sight of one of these early coal-powered lumbering beasts was what really
inspired Henry Ford to start
developing tractors in the 1800s. As he later remembered in his autobiography,
My Life and Work:
"I felt perfectly certain
that horses, considering all the bother of attending them and the expense of
feeding, did not earn their keep. The obvious thing to do was to design and
build a steam engine that would be light enough to run an ordinary wagon or to
pull a plow. I thought it more important first to develop the tractor. To lift
farm drudgery off flesh and blood and lay it on steel and motors has been my
most constant ambition."
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