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Sixty-nine
experts
from
37
countries
and two
experts representing international organisations
(
FAO
and
OECD
) attended the 9th meeting of
the
Club of Bologna, held under the auspices of
CIGR on the 15th - 16th November 1998 to
discuss the following topics:
1)
Soil cultivation: new methods and new
technologies.
2)
Official testing and evaluation of
tractors and implements: a tool to
assist farmers in assessing
performance, safety and
environmental factors.
A brief session was also devoted to the
Indian
tractor industry
as preliminary information on a
subject that will be discussed at the meeting next
year.
The meeting unanimously agreed the following:
Conclusions and Recommendations
1. Soil cultivation: new methods and new
technologies
This important topic
was discussed on the basis
of keynote papers presented by L.
Cavazza
(Italy), H.J.
Heege
(Germany), W.C.T.
Chamen
(U.K.) and El H.
Bourarach
(Morocco) representing the research sector and
by P.
Celli
(Italy), H.
Weiste
(Germany) and
M.
Hodge
(U.K.) representing the viewpoint of
agricultural machinery manufacturers.
The views expressed in the papers reflected the
different soil and climatic conditions that
characterise each speaker's region of origin. In
the opening presentation
L. Cavazza
discussed
the wide range of soil tillage systems ranging from
complex multi-pass systems based on deep soil
inversion to minimum or zero tillage and direct
seeding systems. He concluded that with such a
wide range of mechanised tillage options and
their crucial interaction with agronomic, soil,
topographic, climatic and economic factors it was
not possible to identify a single 'best` system.
Farmers or operators
decisions on the best
method to use would be based on their
knowledge of these factors (perhaps through
expert systems) and on local circumstances at the
time and would always be strongly influenced by
their own experience. Some reduced tillage
systems are useful in erosion control and in
improving stable soil structure although under
some conditions a negative effect of low
germination can occur as a result of poor
drainage and low soil surface temperatures. He
indicated that recent evidence suggests that there
has been a worldwide increase in the area of land
prepared using minimum or zero tillage
techniques. Future trends
will be influenced by
developments in genetically modified plants and
chemical weed and pest control methods that
reduce environmental pollution to more
acceptable levels. However the most important
criteria for the farmer in selecting the most
appropriate tillage system will continue to be
labour and equipment costs, as well as the
agronomic, soil, climatic and other factors
already mentioned. In heavy clay soils traditional
use of the plough may well continue to be the
preferred option. In the context of environmental
protection public administrators
are increasingly
interested in possible interventions to encourage
the use of those tillage systems that are beneficial
to the environment. Although some of the
alternatives to conventional ploughing can have
benefits in terms of runoff, soil erosion and
watercourse pollution restrictive public
intervention will be difficult until our knowledge of
the processes involved is improved.
H.J.
Heege
addressed a number of the
underlying reasons for cultivation. In particular he
discussed the need to adjust soil bulk density and
soil particle size and distribution for efficient plant
growth; weed
control and crop residue
management options and the problems of straw
residue in seeding operations. He indicated that
there were more than adequate options in tillage
techniques available for any given weather
condition but that there was considerable room
4
for improvement in the precision of weather
forecasting to enable operators to select the
appropriate implements and methods for the
weather conditions. There would be further
reductions in the use of the plough for mechanical
weed control due to advances in herbicides and
genetic engineering. There was a need for greater
understanding of the relative merits of p.t.o.
driven and other tined implements
in achieving
appropriate soil bulk density and particle
distribution and in improving energy efficiency
with lower tractor wheel slip. Reduced
acceleration of soil particles to lessen particle
separation in the case of mounted p.t.o. driven
tools also needed to be understood better.
Techniques for handling straw residues left on the
soil from the previous crop were already
available including improved seeder designs,
methods for lifting the straw from the soil during
the seeding operation and improved straw
shredders.
W.C.T.
Chamen
emphasised the importance of
reducing the unit cost of production whilst
minimising
the environmental impact of
cultivation. He stressed the importance of
reducing compaction and energy inputs and of
adopting a systems approach. Soil compaction
creates waste in terms of unnecessary energy
inputs, inefficient water use, crop yield
depression and causes soil erosion, organic
matter loss and the production of greenhouse
gases. Modifications to existing tillage systems
such as reducing depth of ploughing, increasing
the implement working width,
selecting more
appropriate tyres and tyre pressures or adopting
zero tillage where feasible may help. However he
strongly favoured consideration of the permanent
separation of cropped and wheeled areas
through controlled traffic systems based on
gantry tractors as the most cost effective and
practical way of addressing compaction and
environmental impacts whilst reducing the level of
inputs. The development of appropriate
knowledge-based decision support systems for
farmers and operators was also considered to
have considerable potential.
Finally El. H.
