Content uploaded by Theib Oweis
Author content
All content in this area was uploaded by Theib Oweis on Oct 02, 2014
Content may be subject to copyright.
Journal of Environmental Science and Engineering, 5 (2011) 1370-1380
Performance and Adaptation of the Vallerani
Mechanized Water Harvesting System in Degraded
Badia Rangelands
I.A. Gammoh1 and T.Y. Oweis2
1. Department of Horticulture and Crop Sciences, Faculty of Agriculture, University of Jordan, Amman 11942, Jordan
2. International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria
Received: May 3, 2011 / Accepted: May 30, 2011 / Published: October 20, 2011.
Abstract: Rainwater harvesting in micro-catchments such as contour ridges and semicircular bunds is an option for utilizing the
limited rainfall, improving productivity and combating land degradation in dry rangeland areas (Badia). However, implementation of
this practice using manual labor or traditional machinery is slow, tedious and costly, and often impractical on a large scale. These
limitations can be overcome using the “Vallerani” plow for quickly constructing continuous and intermittent ridges. The plow (model
Delfino (50 MI/CM), manufactured by Nardi, Italy) was tested and adapted to dry steppe (Badia) conditions in Jordan. The
performance of the machine, its weaknesses and potential improvements were assessed in the 2006/07 season at three sites on 165
hectares of various terrain, slope and soil conditions. The performance parameters included effective field capacity (EFC), machine
efficiency (ME) and fuel consumption (FC). Field tests were carried out at different tractor (134 HP) traveling speeds, pit sizes and
contour spacings. Overall mean performance indicators gave an EFC of 1.2 ha/h, 51% ME and an average FC of 5.15 liter/ha.
Increasing ridge spacing had a small effect on ME where, increasing traveling speed had a greater effect. A guide table was
developed, relating performance parameters with ridge spacing, speed, and bund size setting. This could be a useful reference for the
implementation and management of mechanized micro-catchment construction in the Badia. The system performed well in the
construction of continuous ridges. However, it was unable to construct intermittent ridges at speeds over 4km/h; problems were
encountered in properly staggering the bunds at successive contours.
Key words: Land degradation, contour micro-catchments, Vallerani system, machine capacity, machine efficiency, Badia.
1. Background
As pressure on land increases, more marginal areas
are being used for agriculture. Much of this land is
located in the arid or semi-arid belts where rain falls
irregularly and over 90% of the precious water is soon
lost to evaporation and surface runoff to salt sinks [1].
Recent intense droughts have highlighted the risks to
human beings and livestock. Consequently, there is
now increased interest and growing awareness of the
potential of water harvesting (WH) as a low cost
alternative for improved crop and rangeland
Corresponding author: I.A. Gammoh, assistant professor,
Ph.D., main research fields: dry land rehabilitation,
mechanization of water harvesting systems. E-mail:
issagammoh@yahoo.com.
production and combating land degradation in this
fragile agroecosystem.
During the last few decades, a number of WH
projects have been implemented in the Eastern
Mediterranean and North and sub-Saharan African
regions. They have aimed to improve plant production
(usually trees, forage crops and shrubs), and in certain
areas to rehabilitate abandoned and degraded lands [2].
While few of the projects were successful in
combining technical efficiency with low cost and
acceptability to local farmers or agro-pastoralists,
others have failed because the technology used proved
to be unsuitable for the specific prevailing natural and
socio-economic conditions of the site. In some areas
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1371
the technical resources and tools were limited [1, 3].
The lack of specialized (unconventional) machinery to
support the implementation of techniques for water
harvesting and plant establishment (catchment
constructing, transplanting or seeding) was one of the
most serious constraints faced. Using conventional
machinery did not prove to be adequate for
rehabilitating large areas. It proved to be imprecise,
tedious, slow and costly. Libbin et al. [4] reported that
the lack of mechanized power limited the
establishment of WH systems in small-scale projects.
Significant progress came with the development of
the mechanized system of collection of surface runoff
known as the “Vallerani System” (named after its
Italian inventor). The first experiments of the
Vallerani system was carried out in 1988 in the
framework of the Integrated Programme for
Rehabilitation of the Damergou (FAI-Niger). In this
system, the WH structures are constructed by a special
plow, of which there are two versions, Delfino
(dolphin) and Treno (train). The Delfino was designed
to construct micro-catchments or semicircular
micro-basins (bunds).
The water-holding capacity of the micro-catchment
is 0.200-0.600 m3, on either side of a continuous ridge.
Using this plow, up to 400 micro-basins per hour can
be constructed by Antinori et al. [5]. Malagnoux et al.
[6] reported even higher rates of construction of
700-1200 micro-basins per hour. To build similar
water harvesting structures using traditional tools and
intensive labor required 80 man/days per hectare [6],
while using the Vallerani ridge-opener [7, 8] 1 to 2
hectares of land could be treated in one hour.
Reports [5, 6, 8] indicate that this system can be
used in areas with an annual precipitation of more
than 200 mm and on slopes of 2%-10%. They have
also shown that the use of the Vallerani plow can be
economic when large areas need to be treated and if
quick action is required. Since 1988, this new
technology has been tested in many countries
(Burkina Faso, Chad, Egypt, China, Kenya, Morocco,
Niger, Senegal, Sudan, Syria, Jordan, and Tunisia),
where a total of nearly 100,000 ha have been treated.
The system was first tested in the steppe rangelands
of Syria [9]. The Vallerani plow was used to construct
micro-catchment intermittent bunds on slopes of 4%
and 6% with catchment areas of 40, 80, and 120 m2
per bund, each planted with two Atriplex shrubs. This
research showed that the mechanized bunds provided
three times more water to the shrubs than those with
no water harvesting bunds. Under micro-catchment,
shrub survival rate was increased from 30% to 90%.
Mechanically constructed bunds outperformed
handmade bunds in all indicators due mainly to the
impact of subsoil ripping.
In 2003 ICARDA initiated a research project
“Communal Management and Optimization of
Mechanized Micro-catchment Water Harvesting for
Combating Desertification in the East Mediterranean
Region” in the marginal steppe of Syria and Jordan.
The project was centered on mechanized
implementation of micro-catchment WH using the
Vallerani system and was aimed at reducing land
degradation and improving the livelihoods of local
communities. In addition to community participation
and institution related aspects, the implementation
process aimed to answer questions related to the
technical performance, cost-effectiveness, and impact
of the mechanized system on soil-water-plant
conditions at the experimental sites.
The work presented in this paper, as part of the
Vallerani project, concentrated on the technical
evaluation and adaptation of the Vallerani mechanized
system to the prevailing conditions in the Badia. The
objectives include:
(1) Performance parameters determined under
varying operational and field conditions;
(2) Guidelines developed for the efficient use and
management of the mechanized system for WH under
Badia conditions;
(3) Technical weaknesses of the system identified
and suggestions for possible improvements developed.
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1372
2. Methods and Materials
2.1 Equipment Description and Field Tests
The machine (model Delfino, Fig. 1) is a hydraulic
single ridge plow with a specially shaped working
body (mounted moldboard type), fitted with a
sub-soiler for fissuring deep soil layers, and a
programmable hydraulically-operated lifting
mechanism. The implement is also equipped with a
front knife that assists stability during operation and a
sweeping blade designed to move back to the ridge the
soil clods that are thrown up by the moldboard out
to the runoff area side. The hydraulic lifting
mechanism uses tractor power take off (PTO),
category II as a source of power to operate the
hydraulic pump.
When the lifting mechanism is activated,
discontinuous ridges (semicircular micro-basins) are
produced, otherwise, the plough can construct only
continuous ridges. The raising and lowering action of
the plow is controlled by a directional control valve
(spool type). This is operated by a ground-driven
wheel through a series of drive/driven sprockets and
chains of different sizes. Depending on the selected
combination of sprockets engaged, four (L+S) pit’s
sizes (Fig. 2a) can be obtained (L = 1.6, 2.5, 3.6, and
4.7 m long, and S = 0.7, 1.1, 1.6, and 2.3 m spacing
between successive bunds, respectively).
The hydraulically controlled movement of the
plough bottom while traveling, alternating from an
upwards to a downwards motion, simulates the
movement of dolphins riding the waves. With each
plunge, the plough digs a semi-circular micro-basin
(eye bow shape bund) and forms a pad of earth
towards the uphill side for catching runoff (Fig. 2a).
Each micro-basin is broken up when the plough is
raised. Staggering the bunds on slopes is essential to
catch the runoff effectively and prevent it from
forming erosive water rills.
The machine was able to create either intermittent
or continuous ridges of 50 + 50 cm wide and 50 cm
high (from the bottom of the ridge), with a 40 cm
ridge depth, plus sub-soiling to 15-25 cm below the
ridge bottom (Fig. 2b).
Fig. 1 The Vallerani machine (Delfino) mounted on 134-hp tractor (Category II-3PHS+540 rpm-PTO).
Moaldboard
bottom Subsoiler
Hydraulic-lift
cylinder
Sweeping
blade
Stability
knife
Ground wheel to control the
timing of lifting
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1373
Fig. 2 (a) The staggered lay-out of the bunds in the field (top view). (b) Soil profile cut of the Vallerani micro-catchment
bund with dimensions.
The machine was designed and built to allow
plowing heavy soils (thick and flat soils of alluvial
origin) that the African farmers were not able to work
with their traditional implements [6]. For the weight
of this plough to be lifted and the movement that
animates it and the necessary execution speed for
optimal operation, a heavy tractor with the power of at
least 130-160 hp (96-119 kW) was required. Working
heavy soils with less tractor power may cause
improper operation of the machine, imposed reduction
of working depth or damage to the hitching system of
the tractor. However, lower tractor power may be
allowed when working lighter soils.
The Vallerani plow (Delfino 50 MI/CM) was
mounted on the 3-point-hitch system (3PHS) of a 134
HP (98.5 kW) tractor (Landini, Italy, model L135 TDI)
and the pump of the hydraulic lifting mechanism of
the plow was powered from the PTO of the tractor.
The field tests to evaluate the performance of the
integrated unit (tractor and Delfino plow) were carried
out on three project sites, in the Majdiyyeh, Mhareb,
and Mafraq regions (Jordanian Badia) for 4, 8, and 6
working days (118 working hours) covering
approximately 20, 85, and 60 hectares, respectively.
The dominant soils in the three test sites were silty
clay loam (a few were silty clay and even fewer were
clay loam and silt loam) with low organic matter,
weak aggregation, platy structure, and crusty surface
with poor vegetation cover. As a result of erosion by
water, the soil depth decreased proportionally with
increased slope. It ranged between 20-50 cm on slopes
higher than 8%, while on locations where the slope
was less than 2%, the soil was more than 160 cm deep.
In some locations, medium-sized stones (5-15 cm
diameter at depths of about 30 cm) were moved with
the plow. In other locations (mostly uphill) shallow
rocky pans were found. In such cases the working
depth was reduced to avoid breaking the soil-engaging
tools. Therefore, the soil and topography conditions of
the mentioned test sites, in general, required lower
operational power than that designed for conditions in
Niger and sub-Saharan African regions that the
machine was initially built for.
Tested on different hilly fields with slopes (Fig. 3)
ranging between 1% and 8%, the machine constructed
both continuous and intermittent (micro-basins)
contour ridges with 4, 8, and 12 m spacing between
ridges, and at different average tractor traveling
speeds (2, 3, 4, and 5 km/h). Speeds greater than 5
km/h were not used due to machine and human safety
considerations. The working depth ranged between 0.4
and 0.5 m while the subsoil ripper reached down to a
depth of 0.5-0.6 m from the soil surface.
Trials were implemented on 165 hectares, on 145
(b)
~
30
cm
~25 cm
Runoff
Cracks and
fissures
~50 cm ~50 cm
2
0
-
30
cm
(a)
Runoff Eye bow
shape bunds
L S
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1374
Fig. 3 Constructing Vallerani micro basins of different
sizes on the contours of different slopes (Badia, Jordan).
hectares of which 21,900 intermittent bunds of four
different sizes (length and spacing) were constructed.
The continuous contour ridges covered an area of 20
hectares, which was estimated to be equivalent to
3,000 bunds.
2.2 Measurements and Parameters
Direct measurements to evaluate the performance of
the tractor/plow system included: time, traveling
speeds, ridge lengths, number of bunds, area covered
and volume of consumed fuel.
2.2.1 Theoretical Machine Capacity
According to Ref. [10], theoretical machine
capacity can be determined by the following equation:
TMCA = V × Ew × 0.1 (1)
where
TMCA is the theoretical machine capacity by area
(worked area per time, hectare/hour);
V is the tractor traveling speed (km/h);
Ew is the effective working width (m), which equals
runoff area length + micro-catchment width;
0.1 is the unit conversion factor.
Eq. (1) is used when both continuous ridges and
intermittent bunds are constructed.
However, if we ignore the length of the runoff
catchment, two other versions of the equation can be
derived:
TMCL = V (2)
and
TMCP = TMCL / (L+S) (3)
where
TMCL is theoretical machine capacity by the length
of constructed ridges (km/hour);
TMCP is the theoretical machine capacity by bunds
(number of constructed bunds/hour);
LP is the length of the bund (m);
S is spacing between successive bunds (m).
Eq. (2) was used when the machine constructed
continuous ridges and Eq. (3) when intermittent ridges
were constructed.
In WH systems, spacing between ridges (length of
runoff area) may vary considerably depending on crop
water requirements, rainfall characteristics and runoff
coefficient. The latter greatly depends on the slope.
Theoretical machine capacity by area (TMCA) can be
conveniently used to compare techniques with similar
spacing between successive ridges or bunds, though
not when different spacings are to be compared. In
such cases, the machine’s effective working width was
ignored and TMCA (Eq. (1)) was replaced by TMCL
and TMCP (Eqs. (2) and (3)) to express the length of
the worked ridges and the number of bunds
constructed per hour, respectively. Such parameters of
machine capacity were thought to be more convenient
for use in these cases.
2.2.2 Potential and Actual Machine Capacities
Two effective machine capacities were considered:
the potential machine capacity (PMCA,L,P), and the
actual machine capacity (AMCA). Both were assessed
by determining either the area A, the ridge length L, or
the number of bunds P constructed over time spent as
measured in the field.
PMCA,L,P took into consideration real time lost on
(a) turning and going back to the start at every new
pass to keep the uphill side to the left side of the
tractor, and (b) aligning subsequent ridges to
maintain proper staggering of bunds or proper
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1375
spacing between ridges.
AMCA took into consideration the time lost on the
factors mentioned above plus the time lost on (a)
switching from one site or one hill to another, (b)
refueling, making adjustments, checkups, maintenance
and breakdowns, and (c) work planning and time
lost due to the lack of skill of the operator. AMCA
counted the area covered over all work hours of all
work days.
2.2.3 Machine Efficiency
According to Ref. [10], machine efficiency is the
ratio of the effective machine capacity to theoretical
machine capacity and hence, two types of machine
efficiency were considered:
(1) Potential machine efficiency, where
PMEA,L,P = (PMCA,L,P / TMCA,L,P) × 100% (4)
(2) Actual machine efficiency, where
AMEA = (AMCA / TMCA) × 100% (5)
2.2.4 Fuel Consumption
FC was assessed per unit area (hectare) for
continuous and intermittent ridges and for different
spacing between contour ridges. FC was also
calculated per bund and per hour for the entire 165
hectares. To measure fuel consumption, a topping-up
method was used, where the fuel tank of the tractor
was fully topped up before starting work, then the
number of liters added to refill the tank again was
determined.
3. Results and Discussion
On the three experimental sites, the
tractor/implement unit constructed continuous and
intermittent ridges smoothly at the preset plowing
depth, traveling speed and micro-basin size, whereas
no overloading incidents were encountered. No
slipping situations due to overload have been met, and
no breakage to the soil engaging tools or to the tractor
hitching devices has occurred. This obviously
indicated that the selected tractor power to operate the
Vallerani machine, under soil and topographical
conditions of the Badia, was adequate.
3.1 Capacity and Efficiency of the System
3.1.1 Machine Capacity in Constructing Contour
Ridges
In constructing continuous ridges, the potential
machine capacity, either by area (PMCA) or by length
(PMCL), increased with increased traveling speed
(Table 1). Nevertheless, this gain in capacity
decreased as the traveling speed increased. For
example, in 4 m ridge spacing, switching from 2 to 3,
from 3 to 4, and from 4 to 5 km/h, resulted in 32%,
20%, and 12% gains, respectively (Table 1).
Increasing spacing between successive ridges
increased machine capacity by area PMCA (Table 1).
This is due to the increase in the effective width
covered by the machine. However, there was no
significant effect of ridge spacing on capacity when
considering machine capacity by length, PMCL.
Therefore, PMCA should be used to evaluate the
technique rather than the machine, while PMCL should
be used to evaluate the machine.
Although increased traveling speed increased
machine capacity, the traveling speed had a
Table 1 Theoretical machine capacities (by area covered
TMCA and by lengths of ridges worked TMCL), and the
respective potential machine capacities (PMCA, PMCL) as
calculated for Vallerani machine at different average
traveling speeds and spacing between successive continuous
ridges over 20 hectares (Badia, Jordan).
Spacing
between
ridges (m)
Average
traveling
speed (km/h)
TMCA
(ha/h) TMCL
(km/h)a PMCA
(ha/h) PMCL
(km/h)
4
2 1 2 0.73 1.46
3 1.5 3 0.95 1.89
4 2 4 1.14 2.28
5 2.5 5 1.28 2.55
8
2 1.8 2 1.25 1.39
3 2.7 3 1.62 1.80
4 3.6 4 2.03 2.26
5 4.5 5 2.29 2.54
12
2 2.6 2 1.82 1.40
3 3.9 3 2.11 1.62
4 5.2 4 2.89 2.22
5 6.5 5 3.21 2.47
a TMCL = Average traveling speed.
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1376
noticeably reverse effect on machine efficiency.
Increasing traveling speed from 2 to 5 km/h reduced
the potential machine efficiency PMEA,L from 70.5%
to 50.5% (Table 2). This reduction can be attributed
to: (1) the time lost by the tractor when turning and
traveling back to start a new ridge was the same at 2
and at 5 km/h speeds; and (2) the theoretical machine
capacity at 5 km/h was 2.5 times greater than it was at
2 km/h (Table 1), while the potential capacity at 5
km/h was only 1.7 times greater than it was at 2 km/h.
Increasing spacing between successive contour
ridges (catchment length) had a slight effect on
potential machine efficiency PMEA,L (Table 2). This
can be attributed to the extra time lost traveling
between farther ridges.
3.1.2 Machine Capacity in Constructing
Intermittent Bunds
Tests revealed that, at speeds around 2 km/h, the
machine was able to construct intermittent ridges of
all calibrated bund sizes (L+S). At speeds of around 3
km/h (Table 3), bund size I was lost (the plow
continued constructing the ridge without being lifted
to form a bund), while bund sizes I, II, and III were
lost at speeds of around 4 km/h. Increasing traveling
speed over 4 km/h resulted in constructing continuous
ridges rather than intermittent ones, a result that has
not been reported previously in any region where the
Vallerani machine was used. The lifting and lowering
action speed was not enough to cope with the
traveling speed. This also explains why traveling
speeds greater than 4 km/h were not shown in Table 3.
Moreover, measurements showed that the four
factory-set bund sizes (L + S) were, in fact, different
Table 2 Potential machine efficiency PMEA,L (%) for
Vallerani machine as affected by traveling speed and
spacing between successive continuous ridges (Badia,
Jordan).
Spacing (m) Traveling speed (km/hour) Average
2 3 4 5
4 72.0 63.3 57.0 51.2 60.9
8 69.4 60.0 56.4 50.9 59.2
12 70.0 54.1 55.6 49.4 57.3
Average 70.5 59.1 56.3 50.5 59.1
from those actually performed by the machine (Table 3).
This can be attributed, first, to the non-synchronous
performance of the hydraulic plow-lifting mechanism
with the traveling speed and second, to the ground
slipping conditions experienced by the tractor due to
the weak structure and traction of the soils in the
Badia. This also explains why the measured bund size
increased with increasing traveling speed. Bund size
IV, for example, measured at 2, 3, and 4 km/h was 6.3,
6.5 and 7.2 m, respectively (Table 3).
When constructing intermittent ridges
(micro-basins), the effects of both spacing between
successive ridges and traveling speed on machine
capacity were similar to those when constructing
continuous ridges. In addition, increasing bund size
had a negative effect on both PMCA and PMCP. In 4 m
ridge spacing, for example, switching from size II to
size IV at 2 km/h traveling speed, greatly reduced
PMCP (from 368 to 177 bund/h), but only slightly
reduced PMCA (from 0.59 to 0.56 ha/h). Such changes
in basin sizes and machine capacities should be
evaluated together with WH system requirements and
with the impact of these changes on soil-water-plant
conditions.
The effect of ridge spacing on potential machine
efficiency (PMEA,P), when constructing intermittent
ridges (Table 4), was similar to that when constructing
continuous ridges. However, the effect of traveling
speed on machine efficiency in constructing
intermittent ridges was not as high as in the case of
continuous ridge. It appears that the time lost by the
operator in ensuring acceptable staggering of bunds
between successive contour ridges had masked the
expected difference in efficiencies between different
traveling speeds. This also explains why the
magnitudes (Table 4) of machine efficiency (55.8%,
52.8%, and 48.3% at 2, 3, and 4 km/h, respectively) in
constructing intermittent ridges were lower than those
obtained (Table 2) in constructing continuous ridges
(70.5%, 59.1% and 56.3% at 2, 3, and 4 km/h,
respectively).
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1377
Table 3 Theoretical machine capacities (by area covered TMCA and by number of bunds constructed TMCP), and the
respective potential machine capacities (PMCA, PMCP) as calculated for Vallerani machine at different spacing between
intermittent ridges, different traveling speeds, and different bund sizes over 145 hectare (Badia, Jordan).
Spacing
between
ridges (m)
Average
traveling
speed (km/h)
Bund size
TMCA (ha/h) TMCP
(bund/h) PMCA (ha/h) PMCP
(bund/h)
Size L + S (m)
Factory set Actually measured
4
2
I 2.3 2.1
1
952 NM NM
II 3.6 3.2 625 0.59 368
III 5.2 4.8 416 NM NM
IV 7 6.3 317 0.56 177
3
I 2.3 NA NA NA NA NA
II 3.6 3.3
1.5
909 0.84 510
III 5.2 5 625 NM NM
IV 7 6.5 462 0.79 244
4
I 2.3
NA NA NA NA NA
II 3.6
III 5.2
IV 7 7.2 2 556 0.96 267
8
2
I 2.3 2.1
1.8
952 NM NM
II 3.6 3.2 625 1.08 375
III 5.2 4.8 416 NM NM
IV 7 6.3 317 0.97 171
3
I 2.3 NA NA NA NA NA
II 3.6 3.3
2.7
909 1.45 490
III 5.2 5 625 NM NM
IV 7 6.5 462 1.49 256
4
I 2.3
NA NA NA NA NA
II 3.6
III 5.2
IV 7 7.2 3.6 556 1.73 267
12
2
I 2.3 2.1
2.6
952 NM NM
II 3.6 3.2 625 1.46 350
III 5.2 4.8 416 NM NM
IV 7 6.3 317 1.29 158
3
I 2.3 NA NA NA NA NA
II 3.6 3.3
3.9
909 1.93 448
III 5.2 5 625 NM NM
IV 7 6.5 462 1.94 230
4
I 2.3
NA NA NA NA NA
II 3.6
III 5.2
IV 7 7.2 5.2 556 2.55 272
L:length of bund, S:spacing between successive bunds, NA:not Applicable, NM:not Measured.
Working 165 hectare in 118 hours gave an actual
machine capacity by area of 1.4 ha/hr Dividing by the
average theoretical machine capacity TMCA calculated
over all worked sites (2.7 ha/h), and multiplying by
100%, the actual machine efficiency over 18 working
days was:
AMEA = (1.4 ha·h-1/2.7 ha·h-1) × 100% = 51%.
This efficiency calculated over 18 working days
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1378
was lower than the efficiency calculated by averaging
all potential efficiencies of continuous ridging (59.1%)
(Table 2) or the efficiency of intermittent ridging
(53.1%) (Table 4). Such differences were due to the
fact that time losses (such as time needed to switch
from one location to another or time for rests,
maintenance and field work planning) were taken into
consideration when calculating actual machine
efficiencies, but they were not considered when
potential machine efficiencies were calculated.
In general, either potential or actual efficiencies, if
compared with efficiencies of regular ridging (or
plowing with a moldboard of similar effective width),
which usually ranges between 75% and 85% [10, 11],
seem to be even lower. Nevertheless, in constructing
WH contour ridges, a level of 53% machine efficiency
is still acceptable knowing that a one-way plow has to
keep plowing in one direction, whereas the tractor has
to spend time turning and going back to the start at
every new pass to keep the basin facing the uphill side
in order to capture the runoff water.
3.1.3 Fuel Consumption
Working 165 ha (~ 24,900 bund) in 118 hours, the
total volume of used fuel was 846.6 L. Thus, the
actual average FC was 5.13 L/ha, 7.17 L/h and 0.034
L/bund.
In working separate fields, increasing spacing
between ridges from 4 to 8 m and from 8 to 12 m
decreased the FC measured per hectare by 19% and
11%, respectively (Table 5). Due to the continuous
implement engagement with soil, constructing
continuous ridges consumed 14% more fuel than
intermittent structures. Averaging FC of both
continuous and intermittent construction (taking into
account the number of worked hectares) resulted in
4.98 L/ha (Table 5), a measure excluding the fuel
consumed on traveling from one field to another.
3.2 Technical Issues and Potential Solutions
Working under the soil and topographical
conditions of the Badia, the performance of the
hydraulic lifting mechanism was affected by the soil
depth. When the machine encountered rocky or
shallow soil (lass than 50 cm), the plowing depth had
to be reduced forcing the ground wheel of the
hydraulic mechanism to loose its continuous contact
with the soil and thus delaying the lifting action of the
plow, which consequently affected the micro-basin set
size and further led to irregular staggering of bunds on
successive contour ridges. Therefore, it was more
stable and convenient to construct shallow continuous
ridges, on the uphill sides, rather than intermittent
ones.
In some circumstances and due to terrain roughness,
the sweeping blade either lost contact with ground and
was therefore not able to throw the soil clods
produced by the moldboard back to the ridge, or it
scraped the soil surface instead of sweeping it, causing
damage to the entrance of the basin. To overcome this
problem a rubber extension was added to the metal
blade. This improved the contact with the soil making
it flexible but not rigid and enabled soil sweeping
instead of scraping.
Staggering between bunds of s ubsequent
Table 4 Potential machine efficiency PMEA, P (%) for Vallerani machine as affected by traveling speed and spacing between
successive intermittent ridges (Badia, Jordan).
Traveling speed 2 km/hour 3 km/hour 4 km/hour
Bund size II IV II IV II IV
Spacing (m) Average spacing
4 59 56 56 53 NA 48 54.4
8 60 54 54 55 NA 48 54.2
12 56 50 49 50 NA 49 50.8
Average speed 55.8 52.8 48.3 53.1
NA = Not applicable.
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1379
Table 5 Fuel consumption (L/ha) as measured in the fields
for continuous and intermittent ridging at different ridge
spacings.
Spacing
(m) Continuous
ridges (20 ha) Intermittent
ridges (145 ha) Average
row
4 6.58 5.81 5.90
8 5.41 4.70 4.79
12 4.79 4.19 4.26
Average
column 5.59 4.90 4.98
intermittent ridges was irregular when: (1) contour
ridges were not parallel, which was very common on
the double grade slopes of Badia; and (2) when the
hydraulic system guide wheel lost contact with the
ground due to the rough surface or to shallow plowing.
To overcome this problem, the guide wheel was
modified so that in these circumstances, it was lifted
to roll against the rear wheel of the tractor instead of
the ground.
The programmable hydraulically-operated lifting
mechanism of the machine began to fail at traveling
speeds of around 4 km/h. At higher speeds, either the
ridge tended to be continuous rather than intermittent,
or the bund size was noticeably increased. This means
that the lifting mechanism had not been fast enough to
raise the plow from the soil (due to insufficient fluid
flow) before the cycle of constructing the next bund
had started. This problem can be attributed to the
relatively low capacity of the system’s pump when
higher flow rates at greater traveling speeds were
required. Replacing the hydraulic pump and the spool
valve with higher capacity ones may be an effective
solution of overcoming such system weakness.
4. Conclusions
The actual capacities and efficiencies obtained in
this study were lower than those previously reported
for Vallerani plows. Nevertheless, the Vallerani
mechanized system for the implementation of
micro-catchment water harvesting bunds and ridges
proved to be a practical way of eliminating much
tedious manual work or even traditional mechanized
systems. The machine field capacity, its effective
efficiency, and its energy consumption were all quite
satisfactory for large-scale rehabilitation and
improvement of dry rangelands productivity in the
East Mediterranean region, as has been previously
shown in other regions.
The machine was easily adapted to Jordanian Badia
condition. The results of the technical tests performed
at different sites under different conditions of the
Badia provide useful guidance for the technical
management of water harvesting systems to be
implemented in the region. With some technical
improvements to the existing machine that were
suggested in this study, the performance tables could
be further enhanced for more effective management of
the system.
The main technical problems encountered were first,
the slow speed of the hydraulic plow-lifting
mechanism, which can be overcome by using a higher
capacity hydraulic system, so enabling the machine to
work at a higher traveling speed and increasing
significantly both the potential field capacity and the
actual efficiency, and second, the improper bund
staggering across the field, which can be partly
improved by modifying the contact conditions of the
ground wheel of the plow-lifting mechanism.
Replacing the one-way plow with a reversible one
will enable the machine to work on slopes in two
directions, which can be expected to significantly
increase the machine’s effective efficiency.
Acknowledgments
This research was part of the project “Communal
Management and Optimization of Mechanized
Micro-catchment Water Harvesting for Combating
Desertification in the East Mediterranean Region”
supported by the Swiss Development Cooperation
(SDC), the water benchmarks of CWANA project
supported by the Arab Fund for Economic and Social
Development (AFESD), the International Fund for
Agricultural Development (IFAD), and the OPEC
Fund for International Development (OFED). The
Performance and Adaptation of the Vallerani Mechanized Water Harvesting System
in Degraded Badia Rangelands
1380
authors would like to also thank the National Center
for Agricultural Research and Extension (NCARE) for
support in the field.
References
[1] T.Y. Oweis, D. Prinz, A. Hachum, Water Harvesting:
Indigenous Knowledge for the Future of the Drier
Environments, ICARDA, Aleppo, Syria, 2001, p. 36.
[2] W.R.S. Critchley, C. Reij, Water harvesting for plant
production: part 2. case studies and conclusions from
sub-Saharan Africa, The Final Report Draft of the World
Bank’s Sub-Saharan Water Harvesting Study, 1989, pp.
160-171.
[3] K. Siegert, Introduction to water harvesting, some basic
principles for planning, design and monitoring, in:
Proceedings of the FAO Expert Consultation, Water
Harvesting for Improved Agricultural Production Cairo,
Egypt, 21-25 Nov., 1993, pp. 9-23.
[4] R.J. Al-Tabini, J.D. Libbin, H. Saub, D.W. Bailey, I.
Abuamoud, J.M. Hawkes, Tal Rimah range rehabilitation
recreating a valuable resource, Report No. 4, Jordan
Component of the Sustainable Development of Dry
Lands Project, New Mexico State Univ., USA and
JBRDC, Jordan, 2008, p. 18.
[5] P. Antinori, V. Vallerani, Experiments with water
harvesting technology with new special ploughs, in:
Proceedings of the FAO Expert Consultation, Water
Harvesting for Improved Agricultural Production,, Cairo,
Egypt, 21-25 Nov., 1993, pp. 113-132.
[6] M. Malagnoux, Degraded arid land restoration for
afforestation and agro-silvo-pastoral production through
new water harvesting mechanized technology, in: C. Lee,
T. Schaaf (Eds.), The Future of Drylands, Paris, France,
2006, pp. 269-282.
[7] D. Prinz, Water harvesting and sustainable agriculture in
arid and semi-arid regions in land and water resources
management in the Mediterranean region, in: Proceedings
of the CIHEAM Conference, Italy, 4-8 Sept., 1994, pp.
745-762.
[8] D. Prinz, Water harvesting for afforestation in dry areas,
in: Proceedings of the Tenth International Conference on
Rainwater Catchment Systems, Mannheim, Germany,
10-14 Sept., 2001, pp. 195-198.
[9] G. Somme, T. Oweis, A. Abdulal, A. Bruggeman, A. Ali,
Micro-catchment water harvesting for improved
vegetative cover in the Syrian Badia, On-farm Water
Husbandry Research Reports Series No. 3, ICARDA,
Aleppo, Syria, 2004, p. 168.
[10] W. Bowers, Machinery Management: Fundamentals of
Machine Operation, 3rd ed., Deere and Company, Moline,
IL, USA, 1987, p. 208.
[11] D. Hunt, Farm Power and Machinery Management, Iowa
State University Press, Ames, Iowa, USA, 1983, p. 365.
