Effect of Implement Combining on Agricultural Tractor Performance

Effect of Implement Combining on Agricultural
Tractor Performance
By
Tarig Dafaalla Awadelkarim Aboelgasim
B.Sc. (Agric.) – Honours
University of Gezira
1998
A thesis submitted to the University of Khartoum in partial
fulfillment for the requirements for the degree of Master of
Science in Agricultural Engineering
Supervisor
Dr. Mohamed Hassan Dahab
Department of Agricultural Engineering
Faculty of Agriculture, University of Khartoum
November - 2003
Dedication
This work is dedicated to
My dear father, Dafaalla who
taught me how men should be.
My gracious mother, Alawia,
who gave me all the love.
My
beloved
Brothers
and
Friends
and
Sisters,
My
sincere
Colleagues
With love and respect…
Tarig
Acknowledgement
From the very beginning to the end I thank Allah who
provides me with health and strength and through whom a
number of relatives and friends and many more than I can
mention helped me throughout this study.
I wish to express my deepest gratitude and sincere
thanks to my supervisor Dr. Mohamed Hassan Dahab for
his generous assistance, advice, keen, guidance and
encouragement.
Special thanks to my family, friends, colleagues and to
them all I remain greatly indebted.
ABSTRACT
The present study was carried out at the demonstration farm of
Faculty of Agriculture, Shambat, University of Khartoum in a clay
loam soil, to investigate the effect of using single (ridger, chisel) and
combination (ridger – chisel) tillage implements on machinery field
performance parameters. The measured parameter included draft
required power, unit draft, slippage, field capacities, efficiencies and
fuel consumption. Also to correlate power requirement with the other
machinery performance parameters.
The results showed that, the implement combination (ridger –
chisel) recorded the highest values of draft (18.4 KN) power
requirement (30.58 Kw), unit draft (8.74 KN/m), wheel slippage
(21.18%) and fuel consumption (12.55 l/hr). Meanwhile the ridger that
lowest values of field capacity (0.90 ha/hr), and efficiency (71.43%).
Statistical analysis showed that, the effect of implement type on
draft, power requirement, unit draft, wheel slippage, field capacity,
efficiency and fuel consumption was highly significant at (1%) level.
Multiple correlation between power required, fuel consumption
effective field capacity and between power required, slippage,
effective field capacity and between unit draft, fuel consumption,
slippage were highly significant (r = 0.84), (r = 0.98) and (r = 0.98)
respectively.
‫ﺑﺴﻢ اﷲ اﻟﺮﺣﻤﻦ اﻟﺮﺣﻴﻢ‬
‫ﺧﻼﺻﺔ اﻷﻃﺮوﺣﺔ‬
‫أﺟﺮیﺖ اﻟﺪراﺱ ﺔ اﻟﺤﺎﻟﻴ ﺔ ﻓ ﻲ اﻟﻤﺰرﻋ ﺔ اﻟﺘﺠﺮیﺒﻴ ﺔ ﺑﻜﻠﻴ ﺔ اﻟﺰراﻋ ﺔ – ﺟﺎﻡﻌ ﺔ اﻟﺨﺮﻃ ﻮم ﺑﺸ ﻤﺒﺎت ﻓ ﻲ‬
‫ﺕﺮﺑﺔ ﻃﻴﻨﻴﺔ ﻃﻤﻴﺔ‪ ،‬وذﻟﻚ ﻟﻤﻨﺎﻗﺸﺔ ﺕﺄﺛﻴﺮ اﺱﺘﺨﺪام ﺁﻻت ﻡﻔﺮدة )ﻃﺮاد ‪ ،‬ﻡﺤﺮاث ﺣﻔﺎر( وﺁﻻت ﻡﺘﺤﺪة )ﻃﺮاد ‪+‬‬
‫ﻡﺤ ﺮاث ﺣﻔ ﺎر( ﻋﻠ ﻰ ﻋﻮاﻡ ﻞ أداء اﻵﻟ ﺔ ﻓ ﻲ اﻟﺤﻘ ﻞ واﻟﻌﻮاﻡ ﻞ اﻟﺘ ﻲ ﺕ ﻢ ﻗﻴﺎﺱ ﻬﺎ ﺕﺤﺘ ﻮي ﻋﻠ ﻰ ﻗ ﻮي اﻟﺴ ﺤﺐ ‪،‬‬
‫اﻟﻘ ﺪرة اﻟﻤﻄﻠﻮﺑ ﺔ ‪ ،‬وﺣ ﺪة اﻟﺴ ﺤﺐ ‪ ،‬إﻥ ﺰﻻق اﻟﻌﺠ ﻞ اﻟﺨﻠﻔ ﻲ ‪ ،‬اﻟﺴ ﻌﺔ اﻟﺤﻘﻠﻴ ﺔ ‪ ،‬اﻟﻜﻔ ﺎءة واﺱ ﺘﻬﻼك اﻟﻮﻗ ﻮد‪.‬‬
‫ﺑﺎﻹﺿﺎﻓﺔ إﻟﻰ ﺕﻮﺿﻴﺢ اﻟﻌﻼﻗﺔ اﻟﺮاﺑﻄﺔ ﺑﻴﻦ اﻟﻘﺪرة اﻟﻤﻄﻠﻮﺑﺔ وﻋﻮاﻡﻞ أداء اﻵﻟﺔ اﻷﺥﺮى‪.‬‬
‫أوﺿﺤﺖ اﻟﻨﺘﺎﺋﺞ أن اﺱﺘﺨﺪام ﺁﻟﺘﻴﻦ ﻡﻠﺤﻘﺘﻴﻦ )ﻃﺮاد – ﻡﺤﺮاث ﺣﻔﺎر( ﺱﺠﻞ اﻟﻘﻴﻢ اﻟﻌﻠﻴﺎ ﻟﻘﻮة اﻟﺴ ﺤﺐ‬
‫)‪ ،(18.4 KN‬اﻟﻘ ﺪرة اﻟﻤﻄﻠﻮﺑ ﺔ )‪ ،(30.58 Kw‬وﺣ ﺪة اﻟﺴ ﺤﺐ )‪ ،(8.74 KN/m‬اﻥ ﺰﻻق اﻟﻌﺠ ﻞ‬
‫اﻟﺨﻠﻔ ﻲ )‪ (21.18%‬وإﺱ ﺘﻬﻼك اﻟﻮﻗ ﻮد )‪ .(12.55 l/hr‬وﺱ ﺠﻞ اﻟﻘ ﻴﻢ اﻟ ﺪﻥﻴﺎ ﻟﻠﺴ ﻌﺔ اﻟﺤﻘﻠﻴ ﺔ ) ‪0.90‬‬
‫‪ (ha/hr‬واﻟﻜﻔﺎءة )‪.(71.43%‬‬
‫أوﺿﺢ اﻟﺘﺤﻠﻴ ﻞ اﻹﺣﺼ ﺎﺋﻲ أن ﺕ ﺄﺛﻴﺮات ﻥﻮﻋﻴ ﺔ اﻵﻟ ﺔ ﻋﻠ ﻰ ﻗ ﻮة اﻟﺴ ﺤﺐ ‪ ،‬اﻟﻘ ﺪرة اﻟﻤﻄﻠﻮﺑ ﺔ ‪ ،‬وﺣ ﺪة‬
‫اﻟﺴﺤﺐ ‪ ،‬اﻥﺰﻻق اﻟﻌﺠﻞ اﻟﺨﻠﻔﻲ ‪ ،‬اﻟﺴﻌﺔ اﻟﺤﻘﻠﻴﺔ ‪ ،‬اﻟﻜﻔﺎءة واﺱﺘﻐﻼل اﻟﻮﻗﻮد آﺎن ذا ﻡﻌﻨﻮیﺔ ﻋﺎﻟﻴﺔ ﻋﻨﺪ ﻡﺴﺘﻮي‬
‫)‪.(%1‬‬
‫اﻻرﺕﺒ ﺎط اﻟﻤﺘﻌ ﺪد ﺑ ﻴﻦ اﻟﻘ ﺪرة اﻟﻤﻄﻠﻮﺑ ﺔ واﺱ ﺘﻬﻼك اﻟﻮﻗ ﻮد واﻟﺴ ﻌﺔ اﻟﺤﻘﻠﻴ ﺔ ﻡ ﻦ ﺟﻬ ﺔ وﺑ ﻴﻦ اﻟﻘ ﺪرة‬
‫اﻟﻤﻄﻠﻮﺑﺔ واﻻﻥﺰﻻق واﻟﺴﻌﺔ اﻟﺤﻘﻠﻴﺔ ﻡﻦ ﺟﻬﺔ ﺛﺎﻥﻴﺔ وﺑﻴﻦ وﺣﺪة اﻟﺴﺤﺐ واﺱﺘﻬﻼك اﻟﻮﻗﻮد واﻻﻥ ﺰﻻق ﻡ ﻦ ﺟﻬ ﺔ‬
‫ﺛﺎﻟﺜﺔ آﺎﻥﺖ ذات ﻡﻌﻨﻮیﺔ ﻋﺎﻟﻴﺔ )‪ (r = 0.98) ،(r = 0.84‬و )‪ (r = 0.98‬ﻋﻠﻰ اﻟﺘﺮﺕﻴﺐ‪.‬‬
LIST OF CONTENTS
Page
Dedication................................................................................................................................
i
Acknowledgements.............................................................................................................
ii
Abstract ...................................................................................................................................
iii
Arabic Abstract ....................................................................................................................
iv
List of Contents ...................................................................................................................
v
List of Tables.........................................................................................................................
viii
List of Figures ......................................................................................................................
ix
List of Plates ..........................................................................................................................
x
CHAPTER ONE: INTRODUCTION .................................................................
1
CHAPTER TWO: LITERATURE REVIEW.................................................
3
2.1. Farm mechanization...................................................................................................
3
2.2. Power sources in the farm.......................................................................................
3
2.2.1. Human power...........................................................................................................
4
2.2.2. Animal power...........................................................................................................
5
2.2.2.1. Implements for draft animals.........................................................................
6
2.2.3. Mechanical power...................................................................................................
7
2.2.3.1. Tractor power.......................................................................................................
8
2.3. Horse power...................................................................................................................
10
2.3.1. Indicated horse power...........................................................................................
11
2.3.2 Brake horse power...................................................................................................
11
2.3.3. Friction horsepower...............................................................................................
12
2.3.4. Mechanical efficiency...........................................................................................
12
2.4. Tillage..............................................................................................................................
12
2.4.1 Tillage objective.......................................................................................................
14
2.4.2 Tillage implements..................................................................................................
14
2.4 The concept of combined tillage-operations....................................................
15
2.5 Machinery performance............................................................................................
18
2.5.1 Machinery field capacities and efficiencies................................................
19
2.5.2. Draft..............................................................................................................................
23
2.5.3 Draw bar power........................................................................................................
24
2.5.4 Slippage (travel reduction) ..................................................................................
25
2.5.5 Fuel consumption.....................................................................................................
26
CHPTER THREE: RESEARCH METHODOLOGY................................
27
3.1. Materials..........................................................................................................................
27
3.1.1. Location......................................................................................................................
27
3.1.2. Soil.................................................................................................................................
27
3.1.3. Agricultural machinery........................................................................................
27
3.1.4. Other implements...................................................................................................
30
3.2. Methods...........................................................................................................................
38
3.2.1. Experimental design and layout.......................................................................
38
3.2.2 Implement combining.............................................................................................
39
3.2.3. Parameters measurement ....................................................................................
39
3.2.3.1. Measurement of forward speed.....................................................................
39
3.2.3.2. Measurement of implement draft.................................................................
39
3.2.3.3. Measurements of draw-bar power..............................................................
40
3.2.3.4. Measurements of unit draft.............................................................................
41
3.2.3.5. Measurement of rear wheel slippage..........................................................
41
3.2.3.6. Measurement of field capacities and efficiencies.................................
41
3.2.3.7. Measurements of fuel consumption...........................................................
43
CHAPTER FOUR: RESULTS AND DISCUSION......................................
44
4.1. Effect of implement type on unit draft (kn/m) .............................................
44
4.2. Effect of implement type on power requirement..........................................
48
4.3. Effect of implement type on wheels slippage................................................
50
4.4. Effect of implement type on fuel consumption (l/hr) ...............................
52
4.5. Effect of implement type on specific fuel consumption (l/kw.hr)
54
4.6. Effect of implement type on effective field capacity..................................
56
4.7. Correlation and multiple correlation …………………….................................
58
CHAPTER FIVE: CONCLUSION AND RECOMMENDATIONS ..
60
5.1 Conclusions.....................................................................................................................
60
5.2. Recommendation.........................................................................................................
60
REFERENCES...................................................................................................................
61
APPENDICES……………………………………………………………………………
65
LIST OF TABLES
Table
Title
No.
1.
Some physio–chemical characteristics of the soil.....................................
28
2
Specification of the two tractors........................................................................
29
4.1
Statistical analysis for experimental parameters........................................
45
4.2
Mean values of experiment parameters as affected by the
implement type..........................................................................................................
46
LIST OF FIGURES
Fig.
Title
No.
3.1
Ridger.........................................................................................................................
32
3.2
Chisel plow..............................................................................................................
34
3.3
Ridger – chisel combination.............................................................................
36
4.1
Relationship between draft, slippage and fuel consumption.............
47
4.2
Relationship between power requirement, fuel consumption and
field efficiency........................................................................................................
4.3
49
Relationship between power requirement, slippage and effective
field capacity..........................................................................................................
51
4.4
Relationship between draft, slippage and fuel consumption
53
4.5
Relationship between unit draft, slippage and specific fuel
consumption............................................................................................................
4.6
55
Relationship between power requirement, fuel consumption and
effective field capacity........................................................................................
57
LIST OF PLATES
Map
Title
No.
1.
Ridger.........................................................................................................................
31
2.
Chisel plow..............................................................................................................
33
3.
Ridger – chisel combination.............................................................................
35
4.
Dynamometer..........................................................................................................
37
CHAPTER ONE
INTRODUCTION
In the modern agriculture, machinery is important and
fundamental for agricultural development in many countries. The
main aim of machinery is to reduce the difficulties of agricultural
operations and costs and to maximize production. Agricultural
mechanization has been receiving considerable interest in recent times
due to increase in world population and need for food.
The manipulation of soil by using suitable implements to secure
a good environment for seed germination and- plant growth is the
main operation of arable agriculture. It is carried out by a high level of
advanced machines. However, it is the most costly operation in the
budget of a farmer. Among all the agricultural operations, tillage
operations require a tremendous amount of power for adequate
seedbed preparation.
Draft, energy and fuel requirements for agricultural implements
have been recognized as essential when attempting to correctly match
on agricultural implement and tractor. The need for tillage implement
is one of the factors, which determine the size of use-age tractor and
also determine quantity of usage of energy in an operation. Other
factors are the machine performance and the time needed for the
machine to accomplish operation.
Therefore, it is important to select the machine or machines to
carry out the specific operation with minimum cost of energy and in
the required time.
The objective of this study is:
1.
To investigate the effect of using single or combination of
implements on machinery performance parameters such as
draft, power slippage, field capacities and efficiencies and
fuel consumption, when the implement linked to a two
wheel drive tractor in a clay loam soil.
2.
To correlate power requirements with other machinery
performance parameters.
CHAPTER TWO
LITERATURE REVIEW
2.1. Farm mechanization:
Agricultural mechanization can be briefly defined as any
mechanical means that can be employed in the process of agricultural
production. It includes the use of hand, animal, engine power,
implement and machines in the production process, transportation and
marketing of agricultural production. Mechanization can be classified
into three stages (Fashina, 1976).
1.
Elementary stage-the use of human power only.
2.
Intermediate stage-the use of both human and animal power.
3.
Advanced stage-completed use of motorized and automated
power.
2.2. Power sources in the farm:
Power source in agricultural farm is one of the determining
factors for the level of agricultural development and stage of
mechanization (Bola et al., 1976).
Power required on the farm for doing two kinds of work,
namely, dynamic work requiring pulling or drafting effort, and
stationary work, usually accomplished by means of a belt, gear or
power take off shaft for transmitting the power.
2.2.1. Human power:
Farming carried out by a hand-tool technology seldom exceeds
subsistence level. The farmer and his family will require to put in their
entire effort to produce their food and only in good years will there be
any surplus production which can be sold in order to buy goods from
market.
An adult human in good health and well-fed has a power
capacity of about 0.07 to 0.1 kw., specially the trained people. The
most commonly used implement by human is the hand hoe. It can be
used in a wide range of soil types with or without a crop or weed
cover. Adequate back clearance is necessary to reduce friction losses
on the back of blade as it enters the soil, thus enabling it to work
deeper by the same effort. The length of the handle depends on the
local tradition, but in general long handle and heavy hands give deeper
work.
The other hand tools widely used is the knife which is used for
light bushes in order to clear the land before cultivation. It is also used
to cut mature crop at harvest time. This tool is not suitable for
cleaning large trees. A local type of axe with a simple triangular–
shaped head in a burnt hole at the thick end of the handle is used to
clear large trees.
Grossley et al. (1983) established a correlation between
available power per hectare and crop yield. Typically in Africa, one
adult works about half a hectare of hand providing about 0.1 kw/ha. If
0.4 kw/ha is taken at the desirable level, then power supplementation
of 0.3 kw/ha is necessary. A pair of oxen would provide such
supplementation for about (3-4) hectares of land for small holder
farm. Inns (1980) suggested that, this was economically the best
solution to increase the production of the small holder farm.
2.2.2. Animal power:
Grossley et al. (1983) stated that, many animals have been used
for draft work or transport but the four species most widely used are
the horse, the ox, the donkey and the dromedary. The latter is patient
and hard but difficult to train and sometimes has an awkward
temperament.
It needs to be stressed that in most cases and whenever possible,
the local indigenous breeds should be used. The use of animals
transferred within country or imported animals should be avoided, as
they are often not resistant to be the local pests and diseases and other
condition.
Glossley et al. (1983) reported that, within a particular species
or animals, the ox as a draft animal must be powerful, compact, and
sturdy with well developed muscles. Its legs should be strong and
short. In case of horses, they will have in addition to the same power
characteristics on the ox, short and straight shoulders.
Concerning the character whatever the species a clam and
docile animal without vices (tendency to kick or bult) should be
sought. Training of ox and horse start at age of two or three years. For
sexes both male and female can be used.
The ox is particularly suitable on fairly soil for deep work
(15cm). The horse is used on light soil for shallow row crop work.
The donkey is suitable for light draft work and load carrying.
2.2.2.1. Implements for draft animals:
The choice for suitable implements is of great importance, both
because of agricultural requirement and the low power availability
from the animal. Many modern systems are now based on the
minimum tillage concept using chisel plow and multi-tined cultivars
where moisture conservation and resistance to soil erosion (Glossley
et al., 1983).
Abdoun (1991) reported that, the use of animal drawn
implements was first common in the northern regions of the Sudan,
but there were no artisan black smiths to service the implements.
Later, a project was initiated and some field implements for the
traditional farmers were manufactured locally. The idea was pioneered
in some neighbouring countries in Africa where oxen pulled plows,
cultivators and small simple seeders which where made in local
workshops by exploiting available materials. The mouldboard plow
had been improved so that it could be converted into a toolbar. A
further study of the Nuba Mountain hoe indicated that all parts with
the exception of spring tines could be made locally.
2.2.3. Mechanical power:
The units for mechanical work are (force X distance). Power
then is the work per unit time. Watt has been used by the (SI) system
as unit of power. One watt is the power equivalent of a newton of
force expended through a meter of distance in one second. One
customary pound of force is approximately 4.448 N. One customary
horse power is the equivalent of 745.7w, and kilowatt (kw) is the
equivalent of 1.341 HP.
Mechanical power is evidence in two forms. Linear power
occurs when a force is exerted with a linear velocity, and rotary power
which is transmitted through rotating bodies. Both former fit the
general relationship of:
Power = force X distance / time ………………. (2.1)
Kepner et al. (1982) reported that, history indicates that the
process of mechanization is dynamic, with no ultimate goal in sight.
As Larger and larger tractors are introduced, tillage tools must be
designed for higher speed or efficiently utilize than drawbar power so
that traction is not a limiting factor. There is a great deal of room for
developing more efficient tillage tools that will require less energy per
hectare to produce the desired effect on the soil.
2.2.3.1. Tractor power:
Tractor power on farms will continue to be absolute necessity
for agricultural production. The total number of workers engaged in
forming has dropped to about 2% of the nations population, yet total
tractors and self-propelled machines within greater power ratings will
be used in the future if the production from a single worker is to
continue to increase (Hunt, 1977). He also reported that tractors
deliver power in several ways. Pulled or towed implements are
powered through the traction of drive wheels and the pull or draft
from the drawbar. Rotary power is obtained from the power take-off
(PTO) shaft or from a belt pulling. Both linear and rotary power can
be produced by tractors hydraulic system.
The tractor power equations are convenient formulas with the
necessary unit factor conversions included in the numerical constant:
i) Drawbar power:
DBP = FS/C………………….……………..………………. (2.2)
Where:
DBP: Drawbar power expressed in kw (HP).
F: Force measured in kw (lb).
S: Forward speed, km/hr (MPH).
C: Constant, 3.6 (375).
ii) PTO power:
PTOP =
2πFRN
…………………………. (2.3).
C
Where
PTOP: PTO power expressed in kw (HP).
F: Tangential force, kn (lb).
R: Radius of force rotation, m (ft).
N: Revolutions per minute (rpm).
C: Constant, 60 (33000).
iii) Hydraulic power:
Hyp =
PW
…………………………….. (2.4)
C
Where:
Hyp: Hydraulic power, kw, (HP).
P: Gage pressure kpa, (Psi).
W: Flow rate, L/s (gal/min).
C: Constant, 1000 (1714).
2.3. Horse power:
The term horse power is defined as a unit of measurement of
power, and 1 hp is equal to doing work at the rate of 33.000 ft.lb per
min or 550 ft.lb per sec. There is no real reason why this unit should
have this particular value. However, it was fixed some time during the
eighteenth century as a result of observations made of the work done
by a horse in England in hoisting freight. It was estimated from these
observations that the average horse was able to lift vertically a load of
150 lb when traveling at speed of 2.5mph, then calculated as follows:
1hp =
150 × 2.5 × 5.280
= 33.000 ft.lb per min. ……………….(2.5)
60
Therefore, 33.000 ft.lb per min was chosen as the rate which the
average horse could work and consequently was termed one horse
power. In calculating the horse power required by a machine, it is only
necessary to determine the total foot-pounds of work done or required
per minute and divide this total by 33.000 factor.
2.3.1. Indicated horse power
The indicated horse power (ihp) of an engine is the power
generated in the cylinder and received by the piston. The power may
be calculated by means of the following formula:
PLA Nn
……………………… (2.6)
2 × 33.000
i.hp =
for four – storke – cycle engine
or:
PLA Nn
……………………… (2.7)
33.000
i.hp =
for two – storke – cycle engine
where:
P: (m.e.p) mean effective pressure.
L: length of piston stork, ft.
A: area of cylinder, sq.in = (bore)2 X 0.7854.
N: (r.p.m).
n: number of cylinder.
2.3.2 Brake horse power
The brake horse power (b.hp) of an engine is the power
generated at the flywheel and available for useful work. Several
methods are used for measuring brake horse power.
2.3.3. Friction horsepower
The friction horsepower of an engine is the power that
consumed operating itself at a given speed without any load. It is the
power required to overcome friction in the moving parts of the engine.
Friction horsepower = i.ph – b.hp ………………….. (2.8).
2.3.4. Mechanical efficiency
The mechanical efficiency of an engine is the ratio of its brake
horsepower to its indicated horsepower, that is,
Mechanical efficiency (percent) =
b.hp
× 100 ……………. (2.9).
i.hp
The principle factors affecting the mechanical efficiency of an
engine are losses due to friction in the moving parts such as the
crankshaft and connecting rod bearings, pistons and cylinders, valve
mechanism, and losses involved in the induction of the fuel mixture
and the exhaust of the residue. The mechanical efficiency of an
internal – combustion engine varies from 75 to 90 percent, depending
upon the load, speed and some other related factors.
2.4. Tillage
Tillage is defined as the practice of modifying the state of the
soil in order to provide condition favorable to plant growth (Bukhari,
1992). Optimizing tillage conserves the soil and water preventing
water logging on the surface, encourage infiltration and control weeds
while providing an optimum seedbed for the crop.
Soil tillage is an integral part of crop production. The aim of
tillage operation is to influence the biological, chemical and
physiological characteristics of the soil, in such away as to creat the
optimum condition for germination, and development of plants. These
operations take into account conservation and improvement of soils as
better environment, for plant growth that ensure high yields in the
long term (Kruse et al., 1984).
Tillage is also defined as those mechanical stirring actions
carried out for the purpose of crop growth (Hunt, 1979). Tillage
operation from economic view represent the most costly single
mechanical item in the budget of an arable farm (Culpin, 1976). On
the other hand, Hunt (1979), reported that tillage absorbs well over the
half of the power expended on the farm. It is of great economic
importance that the machinery manager must understand the operation
characteristics, applicability and performance of the various tillage
machines. Staut et al. (1979), reported that, approximately 20% on the
farm energy applied for tillage operation.
2.4.1 Tillage objective
Kepner et al. (1978), indicated, the main objective of tillage as:
ƒ
To develop a desirable soils structure for seedbed. Granular
structure is desirable to allow rapid infiltration and good
retention of rain fall, to provide adequate air capacity and
minimize resistance to root penetration.
ƒ
To control weeds, or to remove unwanted plants.
ƒ
To manage plant residues, through mixing of trash to soil
which is desirable to reduce erosion.
ƒ
To minimize soil erosion by following such practices as
contour tillage, listing and proper placement of trash.
ƒ
To establish specific surface configuration for planting,
irrigating, drainage and harvesting operations.
ƒ
To incorporate and mix fertilizers and pesticides on soil for
amendment.
ƒ
To accomplish segregation. This involve moving soil from
one layer to another, and the removal of the rocks and the
foreign objects, or crop roots.
2.4.2 Tillage implements:
A tillage tool is defined as an individual soil working element,
such as a plow bottom, a disc blade and cultivator shovel. A tillage
implement consists of a single tool, or group of tools, together with
the associated frame, wheels control and protection devices (Bainer et
al., 1955).
Tillage implements are divided into two main groups, primary
tillage implements, where it is used for deep tillage, such as
moldboard plow, disc plow, chisel plow and sub soil plow. The
secondary tillage implements, which it is used for shallow tillage, such
as, disc harrow, scraper ridge…etc.
2.4.3. The concept of combined tillage-operations
Peterson et al. (1983) described the University of Idaho Chisel
– planter, as a minimum tillage implement, for reducing erosion. The
minimum tillage system was developed by combining three successive
practices used in the area. (a chisel plow for runoff control, fertilizer
applicator and a seed drill with double disk furrow openers), and
classified as a tillage – planting machine. The interests in minimum
tillage or no tillage methods of seeding involve saving time and
energy. A comparison of the chisel – planter and two conventional
methods of seeding have been done to illustrate time and energy
differences. The tested tillage treatments as stated by Peterson et al
(1983) included:
i.
Chisel – planter as one – pass.
ii.
Conventional tillage number (1), (disk plow, harrow disk,
fertilizer, rod weeder and end wheeled drill).
iii. Conventional tillage number (2), (chisel plow, disk harrow,
fertilizer, field cultivator and end wheeled drill).
The study revealed that the fuel consumption differences
between the chisel – planter and conventional tillage number (1) and
(2) were, 29.7 l/ha and 13.8 l/ha and the differences in the time were,
0.6 hr/ha and 0.2 hr/ha respectively.
Peterson et al. (1983) also stated that timelines can also be
accomplished by being able to seed on wet soil, and the grower can
expand his acreage or may use the excess time for management. They
also concluded that the chisel – planter use 70% less fuel, and 49%
less hours per acre than conventional system number (1), and 52% less
fuel consumption and 22% less hours than conventional system
number (2).
A comparison between a culti–planter and wide level disk –
seeder under dry farming condition was made, the superiority of the
culti-planter over the (WLD) was observed, in terms of: ability to saw
under wet condition, placement of the seeds at the proper depth,
uniformity of plant population and height. Harbi et al. (1998), also
stated that the culti-planter was easily operated and maintained, and
got the capability to saw cotton, sorghum, and sunflower seeds. The
main problems of the culti-planter are: the high purchasing price, need
highly powered tractor and probably higher fuel consumption as
compared to (WLDS). These disadvantages call for the development
of a new multi-crop till-planting machine, that can be widely used in
both rainfed and irrigated areas.
Sheruddin et al. (1981) stated that the combination of a rotary
tiller and pneumatic seeder was found to be suitable for one – pass
plow – seeding operation as a minimum tillage system for fuel and
time saving.
Paterno, (1994), studied four types of an up-land multi –crop
seeders, namely, semi-automatic, automatic, plow attached and power
tiller attached. When these were tested for maize planting, they gave
the capacities of (0.03, 0.024, 0.13 and 0.183) hectare per hour
respectively. Abdalla (2000) stated that the ridger plant as a one pass
operating machine, the conventional mechanical and manual system
of planting can be viewed in terms of, fuel consumption (l/fed) by the
conventional mechanical system of planting (separate ridger and
planter) was nearly double that of combined ridger-planter and field
capacity of the combination was approximately double that of the
mechanical system and twelve times the manual, which allows times
saving and expansion of the cultivable area.
2.5 machinery performance
Measures of agricultural machine performance are the rate and
quality at which the operation are accomplished. Performance is an
important measure because few industries require such timely
operation, as agriculture with its sensitivity to season and to bad
weather. Completeness is that portion of quality describing a machines
ability to operate without wasted product.
Hunt (1979), stated, a rate of machine performance is reported
in terms of quantity per time, but in most agricultural field machine
performance is reported as area per hour.
Culpin (1975), stated that, studies of average rates of work
show that performance is often far from what should be possible this
is a resultant of many reasons such as:
1.
Lack of understanding of the tractor's capabilities by the
driver.
2.
Lack of incentive to work fast.
3.
Lack of such necessities as a good tractor seat to permit fast
work to be done in safety and comfort.
4.
The difficulty of matching width of implement to the
tractor's power and speed.
2.5.1 Machinery field capacities and efficiencies
Effective field capacity is the actual rate of performance of land
or crop processed in a given time based upon total field time, (ASAE,
1983). Also it is defined as the actual average rate of coverage by the
machine, based upon the total field time (Bainer et al., 1955).
Hunt (1979), said that, field capacity of an agricultural machine
is the rate at which farm operations are accomplished. He also
reported that, filed capacity can be expressed in terms of area/time i.e.
(acre/hr, ha/hr… or bushels or tones, or bales per hour).
Kepner et al. (1978) said that, implements such as harrows,
field cultivars and combines, would be practically impossible to utilize
the full width of the machine without occasional skips, which is a
function of:
ƒ
Speed of travel.
ƒ
Ground condition.
ƒ
Skill of operator.
Field time is an important factor that must be considered when
measuring the field capacity of any machine. Mausoud et al. (1982)
and ASAE (1983), reported that, field time is the time a machine
spends in the field, measured from start of function activity to the time
the functional activity for the field is completed. The field time
includes the productive time and loss time, where, the productive time
is the actual time that, machine spends in the field to achieve a
specific operation.
Kepner et al. (1978), Stated that, lost time in the most difficult
variable to evaluate in relation to field capacity. It may be lost as a
result of adjusting or lubricating the machine, breakdowns, clogging,
turning at the ends, adding seeds or fertilizer … etc. Time lost does
not include time for daily servicing of the equipment or time lost due
to major breakdowns, but include time for minor repairs in the field.
Hunt (1979), proposed that, the following time fractions to be
considered when computing the capacities or cost of machinery:
1.
machine preparation time.
2.
travel time to and from the field.
3.
Theoretical field time (the time while a machine is operating
in the field at an optimum forward speed and performing
over its full width.
4.
Turning time.
5.
Time to load and unload machine.
6.
machine adjusting time.
7.
Maintenance time (refueling, lubrication, chain, tightening
…etc).
8.
Repair time (the time spent in the field to replace or renew
parts that have become in operative).
9.
Operator's personal time.
Effective field capacity can be calculated by the following equation
(Hunt, 1979).
FC =
SWE
………………….…………………………… (2.11)
C
Where:
FC: effective field capacity ha/hr (acre/hr).
S: travel speed km/hr (mph).
W: rated width of implement m (ft).
E: field efficiency as decimal.
C: constant 10 (8.25).
The theoretical field capacity of an implement is the rating of
field coverage that would be obtained if the machine is performing its
function utilizing hundred percent of the time at the rated forward
speed and always covering hundred percent of the rated width (Kepner
et al., 1978).
Culpin (1975), reported that, theoretical field capacity is
calculated simply by multiplying the distance traveled in an hour by
effective working width. Field efficiency is the ratio of the effective
field capacity to theoretical field capacity, expressed as percent. It
includes the effects of time lost in the filed and failure to utilizes the
full width of the machine (Bainer et al., 1955).
Also field efficiency accounts for failure to utilize the
theoretical operating width of the machine, time lost, operator
capability and habits, operating policy and field characteristic (ASAE,
1983). Hunt (1979), reported that, there are many factors affecting
field efficiency, which can be listed as follows:
1.
Theoretical field capacity of the machine.
2.
Machine maneuverability.
3.
Field shape.
4.
Field patterns.
5.
Field size.
6.
Yield (if harvesting operation)
7.
Soil and crop condition.
8.
System limitation.
2.5.2. Draft
Draft is the total force parallel to the direction of travel,
required to propel the implement (ASAE, 1983). It is also defined as
the horizontal component of pull parallel to the line of motion (Hunt,
1979).
Igbal et al. (1994) reported that, draft requirement of tillage
implements has great concern for designing tillage implements and
deciding suitable tractor size.
From all the studies carried out on draft, several factors
affecting implement draft can be concluded:
1.
Depth of penetration:
Skiekh (1989), reported that, the draft requirement increased
curvilinearly for plow with depth of pentration at constant speed.
Smith and Wilkes (1977), said that, draft increase with increase in
forward. Nagi (1980) and John (1987), said that, the draft increased
with the increase in soil compaction.
Unit draft is the draft per unit area of field cross section, usually
expressed on Newton per square centimeter, or pounds force per
square inch (Kepner et al., 1978).
The specific drafts varies widely, under different condition,
being affected by such factors as the soil type and condition, share
sharpness and shape, depth of plowing and width of furrow slice
(Kepner et al., 1978).
2.5.3 Draw bar power
Draw bar power is the useful power produced by the traction
device and it is the product of the net traction force and wheel forward
velocity (Balel and Dahab, 1997). It is also defined as the power
developed at the hitch of draw bar, and available for pulling, dragging,
or similar tractive effort (Fred, 1966). Hunt (1979), reported that, the
draw bar power in relation to either pull-type or mounted implements,
is the power actually required to pull or move the implement at
uniform speed.
ASAE (1983), reported that, the draw bar power, is that power
developed through the drive wheels, or tracks, to move the tractor and
implement through or over the crop or soil.
Draw bar power is affected by many factors such as, speed,
draft, engine size and soil type, Balel and Dahab (1997), said that the
draw bar powder increased as implement draft increased, but it is not
necessary to have a maximum power at maximum draft force. ASAE
(1983), reported that, the draw bar power performance of tractors
depend primarily on engine power, weight distribution on drive wheel,
type of hitch, and soil surface. They stated also that as the draw bar
pull increases the slip increases but it increases to a certain limit.
Draw bar power can be calculated by following equation (Hunt,
1979).
DBP =
S.D
………………………….……………………(2.12).
C
Where:
DBP: Draw bar power (kw).
S: travel speed km/hr (mph).
D: draft KN. (lb).
C: constant 3.6 (375).
2.5.4 Slippage (travel reduction)
Slip is the relative motion in the direction of travel of the
mutual contact surface of the tractor or transport device and surface,
which supports it. It is also known as power loss (ASAE, 1983).
Clupin (1986) reported that, slippage of tractor's wheels always
wastes power and fuel. With peneumatic tires this wastage may be
serious, event if the wheels do not spin. There are many factors
affecting slippage such as, draft, load, speed, soil condition, and type.
Baloch et al. (1991), concluded that, wheel slippage increases with
increasing the load. Ismail et al. (1981), stated that, the increase in
slippage increases draught of disc. Bukhari et al (1992), reported that,
the travel reduction of disc harrow, in clay loam soil increased with
increase in speed. Bukhari et al. (1988), said that, wheel slip in clay
loamy soil increases when the speed of plowing increased.
Raghron et al. (1977), found that, the compaction reached a
maximum between 15 – 25% slip and was less at higher slip rate.
Clupin (1986), stated that, the amount of the slip is often fifteen
percent. The slip of peneumatic tires is hardly noticeable and on heavy
draft work slip in 15% level has been accepted. Slip can never be
eliminated entirely but can some times be minimized by lightening the
load, and working in higher gear.
2.5.5 Fuel consumption
There are many actors affecting fuel consumption of a machine,
such as load, soil condition and operating speed (Kepper et a., 1978).
Lannemark (1977), reported that, fuel consumption depends upon
many factors e.g.
1.
Machine size.
2.
Size and kind of implement affected.
3.
Travel speed.
4.
Conditions of soil.
Clay soil has a higher break up energy requirement than sandy and
loamy soil. For a given soil, energy requirement increases with bulk
density (Kepner et al., 1978). Aljasimy (1993), said that increase in
speed was accompanied by increase is fuel consumption. Gordon
(1991), found that disc plow consumes much energy, compared to
moldboard plow.
CHAPTER THREE
MATERIALS AND METHODS
3.1. Materials:
3.1.1. Location:
The experiment was carried out at the demonstration farm of
Faculty of Agriculture, Shambat, University of Khartoum at latitude
15º 40"N and longitude 32º 32" E. The total area of the trail was
4800m2 (0.48 ha).
3.1.2. Soil:
The soil of the experimental area is generally clay loam. Some
physical and chemical characteristics of the soil is shown in table
(3.1).
3.1.3. Agricultural machinery:
A) Tractors:
Two tractors were used in the experiment, one for testing
(Massey Ferguson) and the other as auxiliary (Case International) for
pulling the testing tractor. Tractors specifications are shown in table
(3.2).
Table 3.1. Some physio–chemical characteristics of the soil
Mechanical
Depth
Moisture
Bulk Density
(cm)
Content (%)
(g/ cc)
pH
Analysis
Texture
Sand Silt Clay
class
(%)
(%)
(%)
0 – 10
4.0
1.35
8.0
25
27
48
Clay loam
10 – 20
4.2
1.40
8.2
23
26
51
Clay loam
20 – 30
4.5
1.45
8.2
22
25
53
Clay loam
Table 3.2. Specification of the two tractors
Specifications
Tractors
Tested
Auxiliary
Mark
Massey 165
Case International 795
Make
England
American
Diesel
Diesel
Number of cylinder
4
4
Stroke cycle
4
4
Cooling system
Water
Water
Rear tires size
13.6/12.38
13.6/12.38
75 hp
75 hp
Engine type
Power
B) Implements:
Two main tillage implements are used:
ƒ
A fully mounted, Massey Ferguson make, ridger, with three
bottoms spaced at 70cm (plate 1 and Fig. 3.1).
ƒ
A fully mounted, Ford make, chisel plough, with three
bottoms spaced at 70 cm (plate 2 and Fig. 3.2).
ƒ
A combined chisel and ridger implement (plate 3 and Fig.
3.3).
3.1.4. Other implements:
A) Dynamometer:
A spring-type dynamometer, (PIANS 2650), 100 kn, was used
for direct draft measurement (plate 4).
B) Measuring tape:
A measuring tape, 30m long was used for measuring the
dimensions and distances to calculate area and slippage.
C) Steel pegs:
It was used for marking the distance during the experiment.
D) Stop watch:
It was used for determining the time required to determined the
speed and fuel consumption.
Plate 1. Ridger
Fig. 1. Ridger
Plate 2. Chisel plow
Fig. 2. Chisel plow
Plate 3. Ridger – chisel combination
Fig. 3. Ridger – chisel combination
Plate 4. Dynamometer
E) Steel chain:
It was used for linking the tested and auxiliary tractor together
with the dynamometer.
F) Piece of chalk:
It was used for marking the rear wheel of the tested tractor for
measuring the slippage.
G) Measuring cylinder:
It was used for refilling the tractor fuel tank, to determine fuel
consumption duration each operation. It is one – liter capacity.
H) Fuel jerry con:
It was used for transporting fuel to the field.
3.2. Methods:
3.2.1. Experimental design and layout:
A completely randomized plot design was used with three
treatments and four replicates. The treatments included, ridger, chisel
and ridger – chisel implement combination.
The area of the experiment was divided into twelve plots each
of them 400 m2 (20m × 20m). A random distribution of treatments
within the plots was carried out.
There was an space of two meters wide left for turning and easy
maneuvering of the tractor, between the plots.
3.2.2 Implement combining:
The ridger–chisel implement combination resulted from the
attachment between the toolbars of ridger and chisel plow, by using
two rigid spacer clamps, when the chisel plows putted at the front of
ridger (plate 3).
3.2.3. Parameters measurements:
3.2.3.1. Measurement of forward speed:
The forward speed for each operation as measured by recording
the time taken by the tested tractor to travel a distance of 20m. the
forward speed in km/ha was calculated as follows:
Speed (km/ha) =
20m × km × 3600 sec
time need to travel 20m(sec) × 1000 × hr
……… (3.1).
3.2.3.2. Measurement of implement draft:
Measurement of each implement draft was carried out as
follows:
i.
The auxiliary tractor (Case international) and the tested
tractor (Massey Ferguson) were linked together through the
dynamometer using steel chain.
ii.
The auxiliary tractor was first allowed to pull the tested
tractor alone.
iii. The reading of the dynamometer was recorded at every
(20m) distance to collect a number of readings with in each
plot.
iv. The tested tractor was then loaded with the implement
operated at constant depth, which was controlled by the
hand lever of the tractor hydraulic system.
v.
Then the readings were recorded for the same previous
distance of (20m).
vi. Draft was calculated as follows:
Implement draft (KN) = pull of tested tractor + Implement (KN) – pull
of same tractor only
…………………………………………………….
(3.2).
3.2.3.3. Measurements of draw-bar power requirement:
The power exerted by the tractor on the implement was
calculated using the following equation:
Dbp =
D×S
3.6
Where:
Dbp = Draw – bar power (kw).
D = implement draft (KN)
S = forward speed (km/hr).
…………………………… (3.3)
3.2.3.4. Measurements of unit draft:
The unit draft is computed by the following equation:
Unit draft (KN/m) =
Draft(KN)
………..(3.4).
Im plement width (m)
3.2.3.5. Measurement of rear wheel slippage:
The rear wheel slippage (%) was determined as follows:
i.
The rear wheel was marked at the ground surface by apiece
of chalk.
ii.
Five successive distance covered by five revolutions of the
wheel when the tractor was unloaded with implement, were
marked and measured.
iii. Then again another similar five distances covered by the
same number of revolutions were marked and measured
when the tractor was loaded with the implement.
iv. All the above steps were done for all replicates and
treatments.
v.
The slippage was calculated as follows:
Slippage (%) =
Dis tan ce traveled without load − Dis tan ce traveled with load
× 100
Dis tan ce traveled without load
…………………………… (3.5)
3.2.3.6. Measurement of field capacities and efficiencies:
i.
On each plot distances of 20m were marked.
ii.
The tractor started working the plot, then the time in
seconds was recorded using stopwatch. This was done for
each 20m distance in the plot.
iii. Time for turns (sec) at the end of each distance was
recorded.
iv. The productive time was determined as follows:
of time required for 20 m dis tan ce in plot (sec)
Productive time (hr) = ∑
(3.6)
3600
v.
The time required to finish the plot was computed as
follows:
Total time = (time for turns + productive time + other time) … (3.7)
vi. The theoretical, effective field capacities (TFC, EFC) and
field efficiencies (FE) of the plough were then calculated as
explained below:
a. TFC (ha/hr) =
Average traveling speed (m / sec) × width of cut (m) × 1ha × 3600
10000 m 2
……………………………..…
a. EFC (ha/hr) =
(3.8)
Area of the plot (400m 2 ) × 1ha )
…………….(3.9)
time needed to cov er plot (hr ) ×10000m 2
b. FE (%) =
EFC(ha / hr ) ×100
………………………………………….(3.10)
TFC(ha / hr )
c. FE (%) =
Pr oductive time (hr )
×100 ………………………….(3.11)
total time in the field (hr )
3.2.3.7. Measurements of fuel consumption:
The fuel consumption rate was detected as follows:
a. The tractor started working the plot with its full tank capacity.
b. After finishing the plot, the tank was refilled with graduated
cylinder.
c. The amount of fuel used to refill the fuel tank was recorded in
ml.
d. The time taken to finish the plot was recorded.
e. The fuel consumption rates were calculated in liter/hectare or
liter/hour of follows:
The fuel consumption rate (L/ha) =
Re ading cylinder (ml) / 1000
(3.12)
Area of plot (m 2 ) / 1000
The fuel consumption rate (L/hr) =
Re ading cylinder (ml) / 1000
Time required to cov er the plot (hr )
(3.13).
CHAPTER FOUR
RESULTS AND DISCUSSIONS
4.1. Effect of implement type on unit draft (kn/m)
Statistical analysis showed that the type of implement
significantly affected the unit draft (P ≥ 0.01)(Table 4.1and Appendix
A).
It was clear that the ridger chisel combination recorded the
highest unit draft (8.74kn/m) while ridger and chisel plow separately
recorded (5.12kn/m) and (6.64 kn/m) respectively (Table 4.2). The
unit draft of (ridger–chisel) combination is greater than that of ridger
and the chisel plow by 70.7% and 31.6% respectively.
The unit draft of the implement decrease with increase of
machine width. The higher unit draft obtained by the ridger – chisel
combination may be attributed to the high draft obtained by this
implement compared to the ridger and chisel plow. This result is in
line with the findings of Igbal et al. (1994).
The relationship between the unit draft, wheel slippage and
fuel consumption (L/hr) was illustrated in (Fig. 4.1). This figure
showed that implement unit draft was the highest incase of implement
combination and lowest for the ridger. On the other hand, fuel
consumption and wheel slippage increased as implement unit draft
increased.
Table (4.1) Statistical analysis for experimental parameters
Value of F
F-tab
F-cal
Parameters
5%
1%
Unit draft (kn/m)
144.134**
4.26
8.02
Power required (kw)
144.453**
4.26
8.02
Slippage
0.627NS
4.26
8.02
Specific fuel consumption(L/kw.hr)
78.00**
4.26
8.02
Effective field capacity(ha/hr)
54.0815**
4.26
8.02
Field efficiency (%)
17.025**
4.026
8.02
Draft(kn)
144.397**
4.26
8.02
Fuel consumption (L/hr)
3.561NS
4.26
8.02
Fuel consumption (L/ha)
183.021**
4.26
8.02
*: significant at (0.05) level.
**: significant at (0.01) level
NS: Not significant
Table 4.2
25
21.2
15
19.2
18.4
20
12.1
12.4
12.6
10
5
0
Ridger
Chisel
Comb.
10.8
14.0
18.4
Implement draft (KN)
fuel cons.(l/hr)
slippage (%)
figure (4.1) Relationship between draft, slippage
and fuel consumption
4.2. Effect of implement type on power requirement:
The statistical analysis showed that type of implement
significantly affected the power required (P ≥ 0.01)(Table 4.1 and
Appendix B).
It was observed that the ridger – chisel combination recorded
the highest power requirement (30.58 kw), while the ridger recorded
the lowest (17.92 kw)(Table 4.2). The power required for the ridger –
chisel combination is greater than that of ridger and chisel plow by
(70.65%) and (31.53%) respectively.
The higher power required by the (ridger–chisel) combination
may be due to the higher draft force of the implement. This result
confirms the findings of Balel and Dahab (1997), who reported that,
the draw – bar power increased as implement draft increases.
The relationship between power required, fuel consumption
and field capacity was illustrated in (Fig. 4.2). This figure showed that
fuel consumption increased and field capacity decreased when the
implement power requirement increased.
13.8
1
13.6
Fuel consumption (L/hr)
13.2
0.96
13.0
12.8
0.94
12.6
0.92
12.4
0.9
12.2
12.0
Field capacity (ha/hr)
0.98
13.4
0.88
11.8
11.6
0.86
Ridger
Chisel
Comb.
17.9
23.3
30.6
Implement
Power requirment (Kw)
fuel cons.
field capacity
Figure (4.2) Relationship between power
requirement, fuel consumption and field capacity
4.3. Effect of implement type on wheels slippage
Statistical analysis of data showed that wheel slippage not
significantly affected by implement type (Table 4.1 and Appendix C).
The (ridger–chisel) combination resulted in the highest slippage
precent (21.18%) compared to the ridger and chisel plow, which
recorded (18.4% and 19.20%) respectively (Table 4.2). Wheel
slippage of (ridger–chisel) combination is greater than that of ridger
and chisel plow by (15.12% and 10.54%) respectively.
The higher wheel slippage associated with the (ridger – chisel)
combination may be attributed to higher draft forces exerted by the
implement. This result is in line with the finding of Pudhiono and
Mcmillan (1995) and Balel and Dahab (1997). Correlation analysis
was carried between wheel slippage and power required resulted
significantly higher correlation (r = 0.9749)(Table 4.3). The
relationship between wheel slippage, power required and field
capacity was illustrated in (Fig. 4.3). This figure showed that wheel
slippage increased and effective field capacity decreased when the
implement power requirement increased.
0.98
21.5
21.0
20.5
0.94
Slippage %
20.0
19.5
0.92
19.0
18.5
0.9
18.0
E.F.C (ha/hr)
0.96
0.88
17.5
17.0
0.86
Ridger
Chisel
Comb.
17.9
23.3
30.6
Implement
Power requirment (Kw)
slippage
E.F.C
Figure ( 4.3 ) Relationship between power
requirment, slippage and effective field capacity
4.4. Effect of implement type on fuel consumption (l/hr):
Statistical analysis showed that type of implement is
significantly affected the tractor fuel consumption (Table 4.1 and
Appendix H).
The ridger–chisel combination resulted in the highest fuel
consumption rate (12.55 l/hr) while the ridger and chisel plow,
recorded (12.10 l/hr) and (12.36 l/hr) respectively (Table 4.2).
The higher fuel consumption rate recorded by the ridger – chisel
combination may be due to higher draft force and power required and
greater time taken by the tractor. This result is in accordance with the
finding of Belal and Dahab (1997) who observed a direct proportional
relation between the fuel consumption rates and draft force.
The relationship between the fuel consumption rate, draft and
slippage was illustrated in (Fig 4.4). This figure showed that fuel
consumption rate and wheel slippage increased as implement draft
increased.
21.5
13.6
21.0
13.4
20.5
13.2
20.0
13.0
12.8
19.5
12.6
19.0
12.4
18.5
12.2
18.0
12.0
11.8
17.5
11.6
17.0
Ridger
Chisel
Comb.
10.8
14.0
18.4
Implement draft (KN)
fuel cons.
slippage
Figure (4.4) Relationship between draft, slippage
and fuel consumption
slippage (%)
Fuel consumption (L/ha)
13.8
4.5. Effect of implement type on specific fuel consumption
(l/kw.hr):
Statistical analysis of the data showed that, type of implement
significantly affected the tractor specific fuel consumption (P ≥ 0.01)
(Table 4.1 and Appendix D).
The ridger resulted in significantly higher specific fuel
consumption (0.681 l/kw.hr) than the chisel plow and ridger – chisel
combination, which recorded (0.532 L/kw.hr) and (0.410 L/kw.hr)
respectively. The specific fuel consumption of ridger is greater than
that of the chisel plow and ridger – chisel combination by (26.88%
and 64.63%) respectively. This is due to that the specific fuel
consumption of the implement decreases with the increase of power
requirement.
The relationship between the unit draft, specific fuel
consumption and wheel slippage was illustrated in (Fig. 4.5). This
figure showed that specific fuel consumption decreased and slippage
increased when the implement unit draft increased.
21.5
0.70
21.0
0.60
20.5
20.0
0.50
19.5
0.40
19.0
0.30
18.5
0.20
18.0
0.10
17.5
0.00
17.0
Ridger
Chisel
Comb.
5.1
6.6
8.7
Unit draft (KN)
Spesific fuel cons.
slippage
figure (4.5) Relationship between unit
draft, slippage and specific fuel
consumption
Slippage (%)
Spesific Fuel consumption (L/kw.hr)
0.80
4.6. Effect of implement type on effective field capacity
Statistical analysis showed that type of implement significantly
affected the effective field capacity (Table 4.1 and Appendix E).
The ridger resulted in the highest effective filed capacity (0.98
ha/hr), whereas chisel and ridger – chisel combination recorded (0.95
ha/hr and 0.90 ha/hr) respectively (Table 4.2). The effective field
capacity of the ridger was greater than that of chisel plow and ridger –
chisel combination by (3.16% and 8.89%) respectively.
The higher effective field capacity of the ridger may be due to
its lower draft and higher field efficiency, the relationship between the
power required, effective field capacity and fuel consumption was
illustrated in (Fig. 4.6). This figure showed that fuel consumption
increased and effective field capacity decreased when the implement
power requirement increased.
0.98
12.6
0.96
12.4
0.94
12.3
0.92
12.2
12.1
0.9
E.F.C (ha/hr)
Fuel consumption (L/hr)
12.5
12
0.88
11.9
11.8
0.86
Ridger
Chisel
Comb.
17.9
23.3
30.6
Implement
Power requirment (Kw)
fuel cons.
E.F.C
Figure(4.6) Relationship between power
requirement, fuel consumption and effective
field capacity
4.7. Correlation and multiple correlations:
1.
Correlation analysis was carried between unit draft and
wheel slippage, resulted significantly higher correlation (r =
0.97), and between unit draft and fuel consumption (l/hr)
resulted significantly higher correlation (r = 0.99), and the
regression
consumption
between
resulted
unit
draft,
slippage,
significantly
and
higher
fuel
multiple
correlation (r = 0.97).
2.
Correlation analysis was carried between wheel slippage
and power required resulted significantly higher correlation
(r = 0.9749), and the regression between wheel slippage,
power required and field capacity resulted significantly
higher multiple correlation (r = 0.98).
3.
Correlation analysis was carried between effective field
capacity, power required, resulted significantly higher
correlation (r = 0.9687), and the regression between power
requirement, fuel consumption and field capacity resulted
significantly higher multiple correlation (r = 0.84).
Although the implement combination record the highest draft,
slippage, power requirement, and the lowest effective field capacity
and field efficiency, but compared to the two individual implement, it
can save time and energy when carrying out the two operations in one
time.
Table (4.3): Correlation and multiple correlation
Relation
Simple
Multiple
correlation
correlation
F – value
r2
r
R2
R
Unit draft and slippage
0.94
0.97
-
-
Unit draft and fuel consumption
0.98
0.99
-
-
-
-
0.96
0.98
0.98
0.99
-
-
0.98
0.99
-
-
0.98
0.97
-
-
-
-
0.70
0.84
10.6
-
-
0.97
0.98
144.5
Unit draft, fuel consumption
106.8
and slippage
Power required and effective
field capacity
Power required and fuel
consumption
Power required and slippage
Power required, fuel
consumption and effective field
capacity
Power required, wheel slippage
and effective field capacity
CHAPTER FIVE
CONCLUSIONS AND RECOMMENDATIONS
5.1 Conclusions
The following conclusions may be drawn:
1.
The ridger – chisel combination showed the highest average
unit draft, power required, wheel slippage and fuel
consumption and the different between the three implement
was highly significant (P > 0.01) for the unit draft and the
power required only.
2.
The ridger recorded the highest effective field capacity and
field efficiency.
3.
Unit draft, power required, field capacity, fuel consumption,
slippage and specific fuel consumption were found highly
correlated (r = 0.97 to 0.99). The variability in the power
requirement may be predicated from the draft, effective field
capacity and slippage.
5.2. Recommendation
1.
Although combination of implements to do more than on
operation at a time is useful in conserving energy and time,
more
investigation
is
required
for
economic
and
performance justification under different soil conditions.
2.
Consideration to be given for combination between more
varied implements for more convenience.
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APPENDICES
Appendix (A). ANOVA table for Unit draft.
F tab.
S. of V.
D.F
S.S
M.S
Treatment
2
26.425
13.213
Error
9
0.825
0.092
Total
11
27.250
13.305
F calculated
144.134**
5%
1%
4.26
8.02
Appendix (B).ANOVA table for Power required.
F
S. of V.
D.F
S.S
F tab.
M.S
Treatment
2
323.471
161.736
Error
9
10.077
1.120
Total
11
333.548
162.856
calculated
5%
144.453**
4.26
1%
8.02
Appendix (C). ANOVA table for wheel slippage.
F
S. of V.
D.F
S.S
F tab.
M.S
calculated
Treatment
2
16.778
8.389
Error
9
120.676
13.408
Total
11
137.454
21.797
0.627NS
5%
4.26
1%
8.02
Appendix (D). ANOVA table for specific fuel consumption
(L/kw.hr).
F tab.
S. of V.
D.F
S.S
M.S
Treatment
2
0.143616667
0.071808333
Error
9
0.0006
0.001327778
Total
11
0.011
0.073136111
F calculated
54.08158996**
5%
1%
4.26
8.02
Appendix (E). ANOVA table for effective field capacity (ha/hr).
F
S. of V.
D.F
S.S
F tab.
M.S
Treatment
2
0.0104
0.0052
Error
9
0.0006
6.66667E-05
Total
11
0.011
5.2666666667 E-03
calculated
5%
78**
4.26
1%
8.02
Appendix (F). ANOVA table for Field efficiency.
F
S. of V.
D.F
S.S
F tab.
M.S
Treatment
2
36.160
18.089
Error
9
9.557
1.062
Total
11
45.717
19.151
calculated
5%
1%
17.025**
4.26
8.02
Appendix (G). ANOVA table for draft.
F
S. of V.
D.F
S.S
F tab.
M.S
Treatment
2
116.48
58.24
Error
9
3.63
0.403
Total
11
120.11
58.643
calculated
5%
1%
144.397**
4.26
8.02
Appendix (H). ANOVA table for fuel consumption liter/hour.
F
S. of V.
D.F
S.S
F tab.
M.S
Treatment
2
0.698
0.349
Error
9
0.882
0.098
Total
11
1.580
0.447
calculated
5%
1%
3.561N.S
4.26
8.02
Appendix (I). ANOVA table for fuel consumption liter/hectare.
F
S. of V.
D.F
S.S
F tab.
M.S
Treatment
2
3.175
1.588
Error
9
0.078
0.009
Total
11
3.253
1.597
calculated
5%
1%
183.021**
4.26
8.02
Effect of implement type on fuel consumption (L/ha):
Replicates
R1
R2
R3
R4
Mean
A
12.25
12.50
12.38
12.43
12.39
B
13.00
13.13
13.23
13.25
13.15
C
13.63
13.70
13.60
13.63
13.64
mean
12.96
13.11
13.07
13.10
Implements
A: ridger
B: Chisel plow
C: Ridger – Chisel combination
Effect of implement type on fuel consumption (L/hr):
Replicates
R1
R2
R3
R4
Mean
A
11.67
12.20
12.07
12.43
12.10
B
12.10
12.21
12.21
12.93
12.36
C
12.39
12.74
12.65
12.41
12.55
Mean
12.05
12.38
12.31
12.59
Implements
Effect of implement type on draft: (Kn)
Replicates
R1
R2
R3
R4
Mean
A
10.00
12.00
11.00
10.00
10.75
B
13.80
14.20
13.80
14.00
13.95
C
17.90
18.00
18.50
19.00
18.35
mean
13.90
14.70
14.40
14.30
Implements
Effect of implement type on slippage : (%)
Replicates
R1
R2
R3
R4
Mean
A
24.93
14.46
13.92
20.20
18.40
B
22.93
16.83
17.98
18.88
19.20
C
23.97
19.01
22.52
19.23
21.18
mean
23.94
16.76
18.14
19.44
Implements
Effect of implement type on field efficiency
Parameters
Prod.
Turning
Other Time
Tot. Field
F.E
Time (sec)
Time ( sec)
(sec)
Time (sec)
(%)
A
110.68
25.12
1.80
147.60
74.99
B
111.75
40.00
1.25
153.00
73.04
C
111.00
45.60
...
156.60
70.88
Implements
Effect of implement type on power required
Parameters Eff.width
Forward Speed
Draft
Unit draft
Power
Implements
(m)
(Km/hr)
(Kn)
( Kn/m)
(Kw)
A
2.10
6.00
10.75
5.12
17.72
B
2.10
6.00
13.95
6.64
23.25
C
2.10
6.00
18.35
8.74
30.58
Effect of implement type on effective field capaciy
Tot. field
Plot area
Eff.
Forward speed
time (sec)
(m2)
Width (m)
(Km/hr)
A
147.60
400.00
2.10
B
153.00
400.00
C
156.60
400.00
Parameters
Implements
T.F.C
E.F.C
6.00
0.98
1.26
2.10
6.00
0.95
1.26
2.10
6.00
0.90
1.26
Table (4.2) Mean values of experiment parameters as affected by
the implement type
Requirement
Unit
Power
(Kw)
Fuel
Specific fuel
consump.
consump.
consump.
(L/hr)
(L/ha)
(L/Kw.hr)
Slippage
draft
arameters
Fuel
(%)
(Kn/m)
E.F.C
T.F.C
(ha/hr)
(ha/hr)
A
5.12
17.92
18.40
12.10
12.39
0.68
0.98
1.26
B
6.64
23.25
19.16
12.36
13.15
0.53
0.95
1.26
A+B
11.76
41.17
37.56
24.46
25.54
1.21
1.93
2.52
C
8.74
30.58
21.18
12.55
13.64
0.41
0.90
1.26
Where:
A: Ridger
B: Chisel plow
C: Ridger – chisel combination