AGE 322
AGRICULTURAL MECHANISATION
2 Units
Course Lecturer: Engr. Dada P.O.O.
Department of Agricultural Engineering
Office Location: Civil Engineering Building.
Office No:3
FUNAAB
Email: dadafemo@yahoo.com, dadapo@unaab.edu.ng
What is Agricultural Mechanisation
Study of the manufacture, utilisation,
distribution, repair and maintenance
of all machines involving farming
operations from land clearing to
processing.
Use of farm machinery
Aims of Mechanisation
To increase productivity
To remove farm drudgery
To improve on product quality
To reduce cost of labour
To increase income
Provision of employment opportunities
Improve livelihood of farmers
Levels of mechanisation
Human
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–
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Power rating(0.1 HP),
most primitive
Highly inefficient
High energy consumption
Low cultivated area
Animal
– Power rating(1-5 HP)
– Better than manual/human
– Larger capacity for animal drawn tools
– Prone to Tsetse fly infestation
– Competition for meat/milk by humans
Mechanical
–
Power rating(10-200HP)
– More coverage of land
– Highly efficient
– High productivity
– Expensive
– Needs skilled labour
Other sources of Power
Solar
– From the sun (continous, 3.41X106 Joules/m2
– Useful for: space heating, water heating and crop drying
Wind
– Used with wind vanes
Nuclear
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–
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Clean source
Easily controlled
High power generation
Application through electric power
Biogas/Bioenergy
– Renewable source of energy
The tractor
Tractors can be classified in terms of their
capacity (power rating) and type (wheel,
crawler etc).
Wheel type can be of two types namely
Two-wheeled and four-wheeled.
Others include: earth moving types and
industrial types.
Power rating ranges from 1.3 to 150 HP
Selection of farm tractors
To select appropriate size of farm
tractors, the following must be
considered.
Farm area to be cultivated
Type of crops to grow
Soil structure
Financial capability
Size of implement to be driven
Tractor as a Prime mover
Drives all other farm machinery
PTO for energy generation
Provision of Draft power for tillage
tools through 3-hitch system
Used for trailing and transportation
of farm produce
Hydraulic output for equipment lifting
Internal Combustion Engines
Burns fuel internally
Mixture of fuel and air
Power generated by the explosion of
burnt mixture of fuel and air
Common types Include:
– Gasoline/Otto cycle
– Diesel Engine
Engine parts
Stationary parts
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Engine block
Cylinders
Cylinder head
Crankcase
Sump
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Crankshaft
Main bearings
Flywheel
Camshaft
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Piston
Connecting rods
Valves
Valve seats
Rotating parts
Reciprocating parts
Engine Accessories
– Electrical system
– Cooling system
Agricultural Machinery
management
Policies are necessary for successful implementation of
Agricultural mechanization strategy.
Policies are established by Government to achieve
objectives.
strategies defines the way in which policies are
implemented.
Some key policies are:
Subsidies
Credits
Taxes and Duties
Private, Corporate or Government Ownership
Input and output prices
Public investment.
Cost Analysis
The maintenance of an accurate record of costs is an indispensable
part of the machinery manager’s job.
Such records assist decision making processes that are the core of
good machinery management.
Ultimate goal of a machinery manager is to maximize enterprise
profits, get a higher output from his machines at minimum cost.
Time of replacement of a machine is one of the most important
decision making activity of the machinery manager.
Cost analysis (Contd)
Machinery costs are divided into two categories:
Fixed cost (Independent of use) eg. Machinery investment,
taxes, housing, insurance etc.
Variable cost (associated with use) eg. Fuel, daily service,
power, labour, lubrication etc.
Depreciation: The amount by which the value of a machine
decreases with the passage of time whether
used or not.
The value declines due to the following:
Part worn out with use
Expense of operating machine increases with time
New or more efficient machine is available
Change in use of the enterprice.
Cost analysis (Contd)
Methods of calculating Depreciation
1. Straight-line method
2. Declining balance method
3. Sum of the year digits method
Service life of a machine (Physical Life): Needed to estimate
depreciation. It terminates instantly due to irreplaceable
part or irreparable part.
Economic Life of a machine: The length of time from purchase
to that point where it is more economical to replace with
a second machine than to continue with the first.
Accounting life of a machine: Predicted life of a machine in
hours of use based on the surveyed use of existing
machines and on design life used by the manufacturer.
Cost Analysis (Contd)
Renting and Leasing
Repair costs
Interest, tax, Insurance and Shelter
Approximate Annual Cost: Estimation for future cost of use for
farm machines is important to machinery managers. Good
estimates help in costs of production, size selection and
replacement decisions can be made.
The actual costs are determined at the end of each year from
cost records
Approximate Annual cost
Approximate annual cost are determined by summing expected FC and
VC.
The total cost per year of a machine can be expressed as:
AC = FC%/100 X P + CA/SWE X [R&M +L + O+F+T]
Where: AC is Annual cost N/yr
FC is Fixed Cost percentage (decimal)
P is Initial Purchase price (N)
A is annual area use (Acres)
S is Forward speed (km/hr)
W is Effective width of action of machine (m)
E is field efficiency (decimal)
R&M is repair and maintenance cost (N)
C is a constant 10 or 8.25
L is labour cost (N/yr)
O is Oil cost (N/yr)
F is fuel cost (N/yr)
T is Cost of tractor use by the machine (N/yr)
Equipment Selection
An efficient method of matching equipment to the true needs of
agriculture will benefit both the manufacturer and the farmer.
The selection of an equipment is a complex problem at farm level.
To select field machinery, the following factors must be taken into
consideration.
Implement performance
Timeliness
Power availability
Labour
Ability to anticipate and recognize significant trends in the
technology
Machinery selection
In field machinery selection, the most pertinent variable is
size or capacity of the machine.
The basis for selecting the proper capacity field machine is
to find the minimum cost by using the equation:
AC = FC%/100 X P + 8.25/SWE X [R&M +L + O+F+T]
(Where the symbols have their usual meaning)
If all the variables are expressed in terms of per metre of machine wheel
basis with the exception of T, then
AC = f(w)
Graph relating annual cost and machine width.
Power Selection
Cost of power is significant in many operations.
Some implements are self propelled but most are powered by
tractors.
Tractor capacity is designated by horsepower.
The annual cost for a farm power unit can be expected to
consist of
AC = FC%/100 X P + hours used X [R&M +L + O+ KAYV]
Where K = timeliness factor
Y = Potential crop yield (t/ha)
A = Area (acres)
V = Value of crop (N)
Used Equipment
Equipment selection also involves some decision about the
economic of purchasing used machinery. When the price of
a used equipment drops below its actual worth, there is an
economic opportunity for the employment of a used
machine.
In the decision to purchase a used equipment, the
machinery manager should recognize and distinguish
between Price and Value.
The following can also guide decision on purchase of used
equipment.
1. Evaluate wear
2. Recognize the adequacy of prior maintenance
3. Evaluate and judge deterioration due to age
4. Be knowledgeable in performance of various models
5. Be skilled.
Machinery management
Involves thorough knowledge of:
Mechanical principles and limitations of the machine.
Efficient operations in the field
Appropriate machine maintenance
Timely repair and replacement
Selection of a machine system
Economic analysis of actual or proposed activities.
Machinery management (contd)
Discussions on the under listed
Field Operations
Field Patterns
Calibration
Loss determination
Field Adjustments
Repair and maintenance
Preventive maintenance
References
Farm machinery management by
Introduction to farm machinery by Kepner