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tion must be considered in the context of these broader issues.

INTRODUCTION
Effective crop production requires machines---hand tools, animal-drawn implements
and engine-powered equipment. In this paper the focus is on tractors and associated equip-
ment. One might ask—why mechanize? Many less developed countries have abundant cheap
labor or so it seems when looking at national statistics. But a closer look reveals labor short-
ages at key times such as during land preparation or harvesting. Timeliness is a key factor in
agricultural production and mechanization may be necessary to prepare the land for seeding
before the rains come or for rapid tillage in multiple cropping systems (for examples, see
Stout and Downing, 1974). Selective mechanization is an old term used to describe an ap-
proach to mechanization that is compatible with the national goals of development while
maintaining high levels of employment. If a higher level of living for all the people is sought,
does this not require increased production per person? Is the goal to maintain employment for
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all people who are able to work? Even at a near starvation level? Or is there some optimum
allocation of jobs allowing some unemployment where production and individual income and
thus the level of living is maximized for the greatest number of people?
Stout and associates have been involved in these debates for over 40 years. In an arti-
cle by Stout and Downing (1975) in the FAO magazine, CERES, we debated the above ques-
tions. We pointed out that the prerequisites for successful mechanization schemes were and
are quite well known, but that too often one or more critical elements is overlooked or ig-
nored, leading to a predictable failure. We concluded. “Mechanization is a reality. It is not just
an academic theory or a vague concept. It is being used in every country of the world. Let’s
resolve to use mechanization to its full advantage as one input to optimize agricultural pro-
duction and food delivery systems.”
In another article (Stout and Downing, 1974A) published in Shin-Norinsha Publishing
Company’s journal, Agricultural Mechanization in Asia, we argued that selective mechaniza-
tion is a “hope” for farmers in less developed countries. Migration from rural areas to the cit-
ies in search of jobs is a well-known problem afflicting many if not most less developed coun-
tries. Motives for this migration (rural to urban) are a complex mixture of urban “pull”, the
attraction of higher wages, social, cultural, and educational activities and the glamour of
towns; and the rural “push”, the desire to escape from a stagnation that offers only heavy, un-
rewarding jobs in an atmosphere of little hope. We suggested that the lack of employment
opportunities in rural areas, low pay for agricultural work, the seasonal nature and drudgery of
agricultural employment, and the unattractiveness of rural living under existing conditions all
contributee to this urban drift. We went on to say, “Selective mechanization of an appropri-
ate type, used under carefully selected conditions, can provide hope for agricultural workers.
Selective mechanization can thus provide a “counter-pull” to resist the attraction to the city.”
More recently, Clarke and Bishop (2002) wrote, “The availability of power is a pre-
requisite for any agricultural activity whether the source is human, animal or motorized. In
developed country agriculture the general availability of virtually unlimited amounts of farm
power in its different forms is almost taken for granted and comes almost exclusively from
internal combustion engines or electric motors. The human is just the “brain” and control of
the system. However, in most developing countries, the human is also a major source of farm
power.” They went on to say, “In developing countries there is a great variation in the pro-
portional use of the three primary sources of farm power. In some countries there is a dynamic
situation in which human and animal power is being replaced by mechanical power, but in
others, farmers are having to give up mechanical and animal power and revert back to human
power.”
There is no question that uses of tractors increase the land area that can be cultivated,
Figure 1. This study by Clarke and Bishop (2002) also shows that hand, animal draft and
tractors supplied more or less equal amounts of power in developing countries (excluding
China) in 1998, Figure 2. By 2030, Clarke and Bishop expect the proportion of power sup-
plied by hand and animal draft will decrease and tractor use is expected to increase substan-
tially, although some countries may be unable to follow this trend because of increasing fuel
costs and insufficient government-based initiatives for introducing tractor power.
Figure 3 shows the increasing use of agricultural machinery in China, one of the
world’s largest markets(Zhou, et al. 2003).




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Here is a preview of this paper. Some principles for global tractor development are
outlined based largely on the work of coauthor Dr Karl Renius, a noted authority on tractor
design and manufacturing (Renius, 2002; Firodia, Bacher, and Renius, 1989 and 1999). The
view from North America draws heavily on the work of coauthor Dr. John Schueller (Schuel-
ler and Wall, 1986; Schueller and Stout, 1995; Krutz and Schueller, 2000), another noted au-
thority on mechanical design and farm equipment applications. The section on reducing
manufacturing costs is based on Club of Bologna presentations by Reid, Schueller, and Nor-
ris(2003) and also Harms(2003). The prerequisite infrastructure necessary for successful use
of farm equipment comes from Stout and Downing (1976) work published 30 years ago that
is still very relevant today. The recent article in Successful Farming (Mowitz, 2004) outlines
the demise of practical mechanical programs in Agricultural Engineering departments in the
US. Similar de-emphasis on mechanical specialties is taking place around the world (Techni-
cal University of Munich, Silsoe Research Institute, FAO, IRRI, etc.). The paper ends with a
discussion of the need for interdisciplinary teams to solve complex problems facing agricul-
ture and the crucial need for agricultural engineers to be part of those teams (Stout, 1997).

AGRICULTURAL EQUIPMENT INDUSTRY IN THE USA
The agricultural equipment industry in the USA has been rebounding from difficult
times in which sales and profitability suffered and there were continued consolidations. In
general, while there were introductions of new models, they tended to be technical evolutions
rather than revolutions. But there are some areas in which innovations are driving significant
commercial sales.
Light bars and other forms of guidance assistance have been a great bright spot in ag-
ricultural equipment sales, both in aftermarket and original equipment. They allow the
equipment to follow very precise paths. Based upon the Global Positioning System (GPS),
they reduce overlaps and skips, which can be very important in planting, fertilization, and pes-
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ticide applications. They also increase the productivity of other operations. Automatic guid-
ance is on its way to be a requirement for new tractors and some self-propelled equipment,
including fertilizer and pesticide applicators.
Equipment for precision agriculture also continues to sell, although the enthusiasm and
sales are tempered by difficulties in using the technologies for effective management. The
large amount of data manipulation and intervention required, and the uncertainties of what
should be done, have caused some to be disappointed. Yield mapping technologies are be-
coming standard on grain harvesters and variable rate controls are achieving some penetration
on fertilizer and pesticide application. The trend appears to be to make systems, which are
both, easier to use and more open, so that they can be used with more software.
There appears to be a trend for continued adoption of the controller area network
(CAN) bus on agricultural equipment. This standardized communications network allows the
various controllers and other electronic devices to communicate with each other. It has
reached the point of maturity where ISO 11783 is now viewed as the communications stan-
dard for this industry.
Continuously variable tractor hydromechanical transmissions were introduced later
into the USA than into Western Europe. However, their recent introduction has drawn con-
siderable interest. It is likely that they will increase their market share.
Perhaps the overriding concern of those attempting to sell powered agricultural
equipment in the USA is the increasingly strict engine emission standards. This is requiring
very major investments in technology development and will affect equipment prices. The
Tier 3 emissions standards are being reached. However, the very substantial further reduc-
tions in NOx and particulate matter (PM) required in Tier 4 has the industry very concerned.
These standards will start to be applied in 2008 and be completely enforced by 2014. The
strict requirements will probably require advanced engine controls, comprehensive exhaust
after-treatment, and good low-sulfur fuels. The current uncertainty of the available technolo-
gies and the overall costs of the after treatments raise great concerns. Controlling emissions
in agricultural equipment and other off-road machinery can be difficult due to the more ad-
verse and varied conditions of use. The many models and sizes, combined with the relatively
low volumes of sales of those models and sizes, contribute to the difficulty in being able to
devote the resources necessary to solve such a problem.
The agricultural equipment industry has long been globalized. This is not surprising,
given the fact that agriculture of some type is practiced in all countries. This globalization
takes many forms. In some cases it is simple importation of equipment from centralized fac-
tories in developed countries. In other cases, it is local manufacture of foreign designs. One
rather unique situation for agricultural equipment is the global marketing of globally dis-
persed manufacturing to locate the manufacturers near their most natural markets. For exam-
ple, large tractors could be made in North America, medium tractors in Western Europe, and
small tractors in Asia. All sizes might be sold worldwide, but manufactured where they
dominate. Cost of production and achieving sufficient economies of scale may also drive the
particular type of globalization. For example, they may be behind AGCO’s recent decision to
cut combine manufacturing in Denmark to only high-specification models and make a long-
term agreement to have entry-level and mid-level combines manufactured for them in Italy.
Another globalization strategy is to produce the same equipment in multiple locations
throughout the world. This provides the manufacturer with some protection against labor ac-
tions, currency fluctuations, and political situations.
There is much political discussion in the USA about “outsourcing”. There has been a
long, and sometimes politically unpopular, trend for manufacturing to be moved to countries
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with lower labor costs and less regulations, such as countries in Latin America, Asia, and
Eastern Europe. There was also some internal migration in the USA from the northern states
to the southern states. But with the extension of globalization to service, technical, and
managerial tasks, the level of political concern has increased even more. Although the change
has been much less abrupt in the agricultural equipment industry, the trend to globalization
continues. Leading engineering universities in the USA are now making much greater efforts
to prepare students for such environments. For example, twenty percent of the engineering
graduates at the University of Rhode Island also receive a college degree in German, French,
or Spanish language.
The USA agricultural equipment market is the world’s largest in total value, although
more units of certain machines are sold in other large countries, such as India, China, and
Brazil. Due to its size, there are many participants in the market. They include the large mul-
tinationals and manufacturers from North America, Europe, and Asia. Success in the USA,
as elsewhere, depends upon the usual factors of appropriate product, strong dealership organi-
zation, and good parts and service. Importers have been able to prosper especially where they
fill needs which some USA farmers feel are neglected by a perceived concentration of multi-
nationals on large equipment and equipment for high-area crops.
The globalization has also led to the “gray market” issue. These are machines, which
are imported into countries through non-official channels. In the USA, the concern earlier
was most with small tractors from Japan. Now self-propelled forage harvesters and telehan-
dlers from Europe are also an issue. Companies claim that there are problems with warranty,
parts and attachments, and legal liability issues with such imports. Consumers see it as a way
to get unique or less expensive products.
There are many other trends or issues that have recently arisen in the contemporary
USA agricultural equipment industry. These include:
• being concerned with meeting the European Machinery Directive.
• remanufacturing. Will the agricultural equipment companies follow the lead of
Caterpillar who has purchased engine and transmission remanufacturing companies?
• qualified service verification. John Deere is now matching sales delivery or rental
receipts to the dealer’s training. To sell certain pieces of equipment someone from the
dealer’s staff must have passed an exam on the relevant training. Will this apply to
agricultural equipment?
The agricultural equipment industry in the USA appears to be recovering from the
down cycle. This may be due to improved credit availability and lower interest rates, as well
as pent-up demand for replacement equipment. The U.S. Ag Flash Reports (AEM, 2004) re-
leased in September 2004 report USA sales in the January through August sales periods, Ta-
ble 1.
Table 1.
Sales of tractors and combines in the USA.(AEM, 2004)

Equipment Jan - Aug 2003 Jan - Aug 2004
2WD Tractors (< 40 HP)* 92,123 99,297
2WD Tractors (40 - 100 HP)* 40,718 47,655
2WD Tractors (> 100 HP)* 9,141 13,287
4WD Tractors** 1,703 2,199
Self-Propelled Combines 2,596 3,698


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All the tractor categories and the combines show increases in sales. This optimism is
reflected in the total predicted sales forecast for the full year, Table 2.

Table 2.
Predicted sales of tractors and combines in the USA.(AEM, 2004)

Equipment 2004 Forecast 2005 Forecast
2WD Tractors (<40 HP)* 131,485 136,415
2WD Tractors (40 - 100 HP)* 63,761 66,039
2WD Tractors (> 100 HP)* 16,700 16,962
4WD Tractors** 3,376 3,331
Self-Propelled Combines 5,808 6,077
*including tractors with front wheel drive with small wheels
**large tractors with same size front and rear wheels

The situation in Canada has not improved yet, although the market for smaller tractors
is expected to improve in 2005.
The improving USA situation has been reflected in improving profitability for the ma-
jor manufacturers in that market. For example, Deere’s operating profits have gone from
US$252 million to US$817 million to US$1212 million from 2001 to 2002 to 2003. The best
projection for the future of the agricultural equipment industry is that it is a mature market
with most of the sales being replacement equipment. No revolutionary products are being in-
troduced which would create rapid technological obsolescence and radical changes in sales.
The large markets will likely continue to be dominated by the large multinationals, principally
Deere, CNH, and AGCO. Smaller companies and importers will continue to successfully ser-
vice smaller markets and those farmers in large markets who demand the lowest cost equip-
ment. Electronics will continue to increase in importance due to the increased functionality
they provide. However, their contribution to equipment cost will not increase proportionately
due to the electronics industry’s continued cost declines per unit of performance.

GLOBAL TRACTOR DEVELOPMENT
Hundreds of excellent references have been written on engine power, single-axle and
two-axle tractors. No attempt is made herein to cite all the relevant references, but one excel-
lent overview is presented in the comprehensive CIGR Handbook, Volume III, entitled Plant
Production Engineering (Stout and Cheze, Editors, 1999). This handbook deals not only with
tractors, but also with tillage machinery, pest control equipment, harvesters and threshers, and
most other types of farm equipment. It was authored by some 40 experts from around the
world.
The focus in this paper is on a few principles of tractor development, based on the life-
time work of coauthor Dr. Karl Renius. He classifies the worldwide tractor technologies into
five levels as described by the level of tractor functions and technical complexity, Table 3.




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Table 3.
Basic specifications of tractors by technology levels: worldwide view for two-axle tractors.
ROPS means “Roll-Over Protective Structure”. (Renius,2002)




Technology level I is the lowest and V the highest. Reliability and durability are not
included in this classification scheme because a tractor of a low technology level must offer
outstanding durability when operated by an untrained driver, perhaps in a tropical climate, in
heavy soils or paddy fields or with inadequate service.
The lowest technology level, I is characterized by a low power level, only rear wheel
drive, low comfort (no cab), low overturning resistance (typically no ROPS) and very simple
components. Level I represent the predominant tractor population in China (small two axle
tractors) and similar regions. Level I may well meet the needs of many farmers in other less
developed countries. Level I was also found in India in the past, but now India is moving to-
wards Level II.
A new tractor line in India with some interesting principles of technology transfer and
international cooperation was described by Firodia, Bacher, and Renius (1999). This tractor,
called the Tempo OX, focused on the following customer expectations:
• improved power with high torque backup for operating in different agro-climatic
conditions,
• efficient transmission and easy shifting of gears,
• higher capacity of hydraulics with sensitive response,
• good ergonomics,
• high reliability,
• reduced vibration and noise, and
• modern appearance.

The OX family of tractors is fully indigenous (in India) and therefore can be manufac-
tured at very low cost. What has been created is truly a modern tractor, comparable in per-
formance and characteristics to world market standards in its class.
Level IV describes the typical modern tractor in highly developed regions such as
Mid-Europe, North America, Japan and others. But these markets are moving toward Level V,
mainly characterized by infinitely variable transmissions and more sophisticated diesel en-

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gines---both with electronic control systems and common automatic control strategies, also
called “drive line management”.

TECHNOLOGY LEVELS FOR TRACTOR COMPONENTS
The principle of definition of technology levels can also be applied to tractor compo-
nents. The transmission is considered the most important component in terms of first cost,
mostly in terms of development costs.
The tractor transmission consists mainly of the speed change and reverse gearbox, the
final drive with service brakes, the four-wheel drive mechanism and the PTO drive line often
including auxiliary drives such as the main hydraulic pump. The most important differences
regarding technology levels can be found in the speed change concept, Table 4.

Table 4.
Technology levels for tractor transmissions (concentrated on the speed change and
the reverser functions). SG: Sliding Gear shift, CS: Collar Shift, SS: Synchronised Shift,
HiLo: 2-speed power shift, PPS: Partial Power Shift (3 or more speeds), FPS: Full Power
Shift (all speeds), CVT: Continuously Variable Transmission, ( ) options.(Renius, 2002)




The simplest gearbox of Level I offers only 6 forward and 2 reverse speeds, and shift-
ing is done by sliding gears or collar elements covering a relatively small speed range. This
technology was typical for Western Europe and North America in the 1950s and later became
important for several developing countries (India for example). At this time the Indian market
requirements move towards Level II. For example, the transmission in the Indian Tempo XO
tractor is synchronized with 4 basic speeds and a mixture of collar shift and sliding gear shift
resulting in 8 forward and 4 reverse speeds. It has alarge master clutch, 2 PTO speeds, high-
performance lifetime wet disc brakes and an extra strong final drive.
Level III has been typical for smaller tractors in the industrialized countries while the
popular concept is toward Level IV in recent years. Level V represents an increase in tech-
nology with infinitely variable transmissions of a new-sophisticated generation. They offer
considerably higher efficiencies and more automatic functions than is the past. Compared
with, The energy loss of the new CVT units (without final drive) is only about half that of
conventional hydrostatic units such as used on Japanese tractor transmissions due to the
power split principle and optimized or completely new axial piston units.


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Tractor manufacturers marketing their products in many counties must minimize the
number of mechanical parts in each family of their complete tractor line. Such a manufacturer
can use interchangeable parts at Levels IV and V, but it will be difficult to use the same parts
for Levels I and II which are typical for countries such as China and India. Less developed
countries should therefore look for technology transfer strategies based on proven tractor de-
signs suitable for their level of technology.
Reducing Manufacturing Costs (Reid, Schueller, and Norris, 2003; Harms, 2003):
For agricultural equipment to be practical, it must be affordable to the users and prof-
itable for the manufacturers. Therefore, manufacturing productivity and efficiency of agricul-
tural equipment is an important part of the systems engineering necessary to improve our food
production systems.
Figure 4 illustrates the processes the agricultural industries use in the development of
new products. It shows the linkage between the new concepts for products that come from
Product Planners or Advance Engineering groups and results in identification of a product de-
velopment timeline including the influence of R&D, manufacturing, sales, service and fi-
nance. New concepts inputs to the process are heavily influenced by the ability of the manu-
facturer in providing the capabilities to be found in new products. The output of the process is
products that meet customer needs. This leads to consideration of product families (e.g, trac-
tor series), re-use of well-developed subsystems (e.g., transmission and engine components),
and manufacturing capabilities of the organizations. Strong supplier relationships have been
used to provide those components that do not differentiate the manufacturer from their com-
petition (e.g. hydraulic components). Over the years, these processes have interacted to result
in a highly efficient organization for the production of agricultural equipment.
But the efficiencies that have been accomplished over the last twenty years are being
further stressed to become more efficient in the face of decreased sales and changing distribu-
tion of the agricultural workforce worldwide. User requirements for additional electronics,
controls and corresponding software require a high level of manufacturing efficiency while
adding an ever increasing level of complexity to the management and manufacturing proc-
esses. To meet these additional requirements and because project management is an out-
growth of systems management, traditional project management is migrating towards the use
of system engineering tools. Through the application of these tools, the design, manufacture,
and life cycle of products are considered early in the project development cycle. Early appli-
cation of systems tools reduces cost, improves efficiency and minimizes risks associated with
increased electrical content.




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Figure 4. Example schedule of managing new projects (Reid, Schueller and Norris,
2003)

ELECTRONICS AND MECHATRONICS SYSTEMS
Replacing mechanical functionality with electronic functionality might also reduce
manufacturing costs. Just as electromechanical servomotors are computer-tuned to get re-
sponses based upon their industrial application, agricultural equipment components can be
similarly adjusted.
In the markets of less-developed countries, it may make sense to have a slower adop-
tion of electronic content in equipment since a critical issue is the serviceability of machines
in the field. This is based on the presumption that less developed countries find it easier to
support a mechanical-service infrastructure than an electrical-service based infrastructure.
Mechatronics is the synergistic combination of mechanical engineering, electronic en-

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