Yield and Water-Use of Tomato under Deficit-Irrigation and Mulch Practices at Kano River Irrigation Project

Abstract

The effects of deficit irrigation and mulching practices to crop yield and crop water use (CWU) of tomato crop were examined at Kano River Irrigation Project (KRIP), during 2014 dry season irrigation farming. The experiments comprised of four levels of water application depths (40, 60, 80, and 100% of weekly reference evapotranspiration) and four levels of mulching; No-Mulch (NM), rice-straw-mulch (RSM), wood-shaving-mulch (WSM) and white-polyethylene-mulch (WPM). The total mean yield ranged from 6.98 to 23.67 t/ha with an annual average of 11.48, 18.48, 11.98 and13.33 t/ ha for NM, RSM, WSM and WPM treatments respectively. The seasonal applied water (SAW) ranged from 362.92 to 907.28 mm while the seasonal crop water use (SCWU) was found to be between 250.73 and 782.60 mm. The results of SCWU of fully irrigated treatment were NM (782 mm), RSM (725 mm), WSM (692.83 mm) and WPM (629 mm). The least value in the range was obtained in the I40 (60% deficit) treatments with WPM, while the highest value in the range was recorded in the I100 treatment with NM. The analysis of variance shows that SCWU was largely influenced by both the water application depth and mulching and it further revealed that the effect of various levels of irrigation and mulching practices on yield were found to be highly significant (**) at 5% level of significance with high mean yield value of 15.84t/ha and 18.48t/ha and also with mean CWU value of 675.40mm and 556.60mm obtained at I80 and RSM. This implies that both deficit-irrigation and mulching practices of tomato crop has significant effect on yield and CWU of tomato grown in the study area. However, it was analytically concluded that the best level of irrigating tomato crop at the site is at I80 giving mean yield of 15.84 t/ha at mean crop water use of 675.40 mm/season and 366 this corresponded to mulching practice of RSM (mean yield of 18.48t/ha and mean CWU of 556.40mm/season) and therefore, tomato producers in KRIP, may adopt water application at I80 and use of RSM as a way of suitable deficit irrigation and water conservation respectively.

Full text

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Yield and Water-Use of Tomato under Decit-Irrigation and
Mulch Practices at Kano River Irrigation Project.
Zakari, M. D 1 *, I. Audu 2, .E. Igbadun 3, N.J. Shanono1, M. M. Maina1, N.M. Nasidi 1, A.
Shitu 1
1. Department of Agricultural Engineering, Bayero University, Kano
2. Department of Agricultural Engineering, University of Maiduguri
3. Department of Agricultural Engineering, Ahmadu Bello University, Zaria
* mdzakari.age@buk.edu.ng
Abstract
The effects of decit irrigation and mulching practices to crop yield and crop water use (CWU)
of tomato crop were examined at Kano River Irrigation Project (KRIP), during 2014 dry season
irrigation farming. The experiments comprised of four levels of water application depths (40,
60, 80, and 100% of weekly reference evapotranspiration) and four levels of mulching; No-
Mulch (NM), rice-straw-mulch (RSM), wood-shaving-mulch (WSM) and white-polyethylene-
mulch (WPM). The total mean yield ranged from 6.98 to 23.67 t/ha with an annual average of
11.48, 18.48, 11.98 and13.33 t/ ha for NM, RSM, WSM and WPM treatments respectively. The
seasonal applied water (SAW) ranged from 362.92 to 907.28 mm while the seasonal crop water
use (SCWU) was found to be between 250.73 and 782.60 mm. The results of SCWU of fully
irrigated treatment were NM (782 mm), RSM (725 mm), WSM (692.83 mm) and WPM (629
mm). The least value in the range was obtained in the I40 (60% decit) treatments with WPM,
while the highest value in the range was recorded in the I100 treatment with NM. The analysis
of variance shows that SCWU was largely inuenced by both the water application depth and
mulching and it further revealed that the effect of various levels of irrigation and mulching
practices on yield were found to be highly signicant (**) at 5% level of signicance with high
mean yield value of 15.84t/ha and 18.48t/ha and also with mean CWU value of 675.40mm and
556.60mm obtained at I80 and RSM. This implies that both decit-irrigation and mulching
practices of tomato crop has signicant effect on yield and CWU of tomato grown in the study
area. However, it was analytically concluded that the best level of irrigating tomato crop at the
site is at I80 giving mean yield of 15.84 t/ha at mean crop water use of 675.40 mm/season and

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this corresponded to mulching practice of RSM (mean yield of 18.48t/ha and mean CWU of
556.40mm/season) and therefore, tomato producers in KRIP, may adopt water application at
I80 and use of RSM as a way of suitable decit irrigation and water conservation respectively.
Keywords: Decit irrigation, Mulching, Yield, Crop water use, Tomato.
Introduction
Crop water use is an important factor
in planning, designing and execution
of agricultural water management
particularly in irrigation of
tomato crops. In Nigeria, tomato
(Lycopersicon esculentum) is one
of the important and popular grown
crop. It has less popularity and use
when it was rst introduced to Europe
from the Northern Andes in the early
days of New World exploration,
but today, tomato is a major World
Food Plant, the production of which
comes to about 18 million tonnes
yearly, mostly in Europe and North
America (Bodunde, 1998). Tomato
is grown almost throughout the
country (Nigeria) but the most
important areas lie in the Northern
and South-western parts of Nigeria.
In the Southern parts of the country,
the crop is grown in small holdings
under rain-fed conditions while it is
grown extensively under irrigation
in the Northern parts of the country
(Olorunaiye, 2009). Tomato yields
of between 18 and 52 tonnes/ha have
been reported for northern savannah
regions (Quim, 1980) and between
12 and 24 tonnes/ha for southern
rainforest areas of the country
(Oyinlola and Akintoye, 2004).
Much lower yields are obtained in
local farms because of the use of
low yielding varieties, diseases and
pests problems and also inadequate
cultural management as well as
reliance on rain-fed production and
residual soil fertility (Olorunaiye,
2009). Northern part of Nigeria been
the major area where tomato crop is
mostly grown in Nigeria, especially
under irrigation therefore requires
proper management of water as
reporte by Thimme et al., (2013) that

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fresh water is becoming increasingly
scarce worldwide, aridity and drought
are natural causes of scarcity and
more recently, however, man-made
desertication and water shortages
have aggravated natural scarcity
while at the same time population
is increasing and there is increased
competition for water among water
user sectors and regions. Thus,
improved management and planning
of the water resources are needed to
ensure proper use and distribution
of the water among competing
users. Scarce water resource and
growing competitions for water will
reduce its availability for irrigation.
Achieving greater efciency of
water use will be a primary challenge
for the near future and will include
the employment of techniques and
practices that deliver a more accurate
supply of water to crops. It is on this
note that crop water use (CWU)
is an important factor in planning,
designing and implementing
agricultural water management.
Hence, decit irrigation is required;
which is the practice of irrigating
crops deliberately below their water
requirements. Such practice is aimed
at minimizing water applied to the
crop so as to maximize crop yield per
water applied. Decit (or regulated
decit) irrigation is one way of
maximizing water use efciency
(WUE) for higher yields per unit of
irrigation water applied. Reduced
yield as a result of decit irrigation,
especially under water limiting
situations, may be compensated
by increased production from the
additional irrigated area with the
water saved by decit irrigation
(Bekele and Tilahun, 2007; Ayana,
2011 and Igbadun and Oiganji, 2012).
Mulching practice is one of the ways
in which water can be conserved.
According to Igbadun and Oiganji
(2012), mulching is well known
to be one means of conserving soil
moisture and reducing evaporation
from the top soil. Mulching can
be done with organic or inorganic
materials like polyethylene sheets.
Besides conserving soil moisture,
polyethylene mulch also increases
soil temperature and moisture in

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early spring, reduces weed problems
and certain insect pests and also
stimulates higher crop yields by
more efcient utilization of soil
moisture (Igbadun and Oiganji,
2012). Lack of knowledge on crop
water use by farmers in the study
area led to application of unknown
quantity of water to tomato crop
in the study area which led to the
development of crop water decit
or over irrigating the crop and these
resulted to reduced yield and waste of
available water for irrigation due to
improper management as practiced
by the farmers in the study area. In
achieving proper management of
applying amount of water required
to tomato crop and harness yield,
there is need to determine the effect
of decit irrigation and mulching
practices on yield and crop water
use at Kano River Irrigation Project
(KRIP), Kano-Nigeria. Hence, it is
expected to generate information
that will be useful to the farmers
for the general improvement of
tiirrigation and conservation of
water management in the study area.
Consequently, the results obtained
from the research can also be used
as a guide by researchers for further
research and design of irrigation
systems. Therefore, the objectives
of this study are to determine the
yield and water use of tomato under
decit irrigation and mulch practices
at Kano River Irrigation Project
(KRIP). In this research, tomato UC
82B variety was used. UC 82B is a
tomato variety that is grown during
dry season and harvesting of the fruit
start from 75 – 80 days.
MATERIALS AND METHODS
Climate and location
The study was conducted at the
Irrigation Research Station, Kadawa,
situated in the Kano River Irrigation
Project I (KRIP) under Hadejia
Ja’amare River Basin Development
Authority (HJRBDA), it is located
between latitudes 11°32`N and
11°51`N and longitudes 8°20`E and
8°40`E within the Sudan savannah
zone of Northern Nigeria (Jibrin et al.,
2008). It has a planned gross irrigable
area of 22,000 ha comprising two
main canals called the West Branch

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and East Branch canals as Phase I
and Phase II, respectively. The study
area, being tropical, has wet-and-dry
climates with relatively wide and
rapid changes in temperature and
humidity. The mean daily maximum
and minimum temperatures are 31°C
and 21°C, respectively. Rainfall
is concentrated between July and
September with maximum and
minimum of 214.0 mm and 132.7
mm per month, respectively as
reported by Maina et al., (2012) and
the rains are preceded by violent
sand storms and the average annual
rainfall is 884.4 mm with 60% of
which falls in July and August.
Field/Laboratory Work
Soil Moisture content: The
moisture content was determined
gravimetrically by the process
described by Michael and Ojha,
(2005) using Equation 1.
100×
−
=
s
sw
M
MM
MC
(1)
Where MC = moisture content in %,
(dry basis)
Mw = mass of wet soil, (g)
Mg = mass of oven dried soil, g
Bulk density: Bulk density was
evaluated using the core sampler
method (Grossman and Reinsch,
2002), using Equation 2.
s
b
c
M
PV
=
(2
)
Where, ρb is the soil bulk density in
g/cm3, Ms is the mass of oven dried
soil, in g, and Vc is the volume of the
core cutter in cm3.
Description of experimental
treatments
Fieldwork was conducted using
tomato crop of UC 82B variety at
KRIP, Kadawa. The eld experiments
consisted of 16 treatments. The
treatments comprised four levels of
irrigation (water application depths)
and four levels of mulch practices,
thus constituting a 24 factorial
experiment. The four levels of
irrigation included water application
depths of 100, 80, 60, and 40% of
weekly reference evapotranspiration
(WRET), while the four levels of
mulch practice consisted of no
mulch (NM); use of rice straw
(RSM), wood shaving (WSM) and

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white polyethylene (WPM). The
16 treatments were replicated three
times, making a total of 48 treatments.
Table 1 gives further description of
the experimental treatments. The
experiments were laid on the eld
with treatments assigned to plots in
a randomized complete block design
(RCBD), with the blocks lying across
the general slope of the eld. The
blocks were separated by a distance
of approximately 3.5m, while the
basins in each block were separated
by a distance of approximately 1m
which minimizes lateral movement
of water from one basin to another.
Table 1: Description of experimental treatments.
Treatment
No.
Treatment
label Description
1 I100MNM Water application depth of 100 % WRET, no mulch.
2 I80MNM Water application depth of 80 % WRET, no mulch.
3 I60MNM Water application depth of 60 % WRET, no mulch.
4 I40MNM Water application depth of 40 % WRET, no mulch.
5 I100MRSM
Water application depth of 100 % WRET, mulched with rice
straw.
6I80MRSM
Water application depth of 80 % WRET, mulched with rice
straw.
7 I60MRSM
Water application depth of 60 % WRET, mulched with rice
straw.
8 I40MRSM
Water application depth of 40 % WRET, mulched with rice
straw.
9 I100MWSM
Water application depth of 100 % WRET, mulched with wood
shaving.
10 I80MWSM
Water application depth of 80 % WRET, mulched with wood
shaving.
11 I60MWSM
Water application depth of 60 % WRET, mulched with wood
shaving.
12 I40MWSM
Water application depth of 40 % WRET, mulched with wood
shaving.
13 I100MWPM
Water application depth of 100% WRET, mulched with white
polyethylene
14 I80MWPM
Water application depth of 80% WRET, mulched with white
polyethylene
15 I60MWPM
Water application depth of 60% WRET, mulched with white
polyethylene
16 I40MWPM
Water application depth of 40% WRET, mulched with white
polyethylene

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Agronomic operations
A land area of 60 m × 25 m was
prepared into levelled basins of 2.5
m × 2.5 m. The eld was weeded and
then irrigated before transplanting.
Tomato (UC 82B variety) seedlings
was transplanted on 14th January,
2014. The tomato seedlings were
raised (24/12/2013 to 14/1/2014)
in the nursery and transplanted
three weeks after planting. Tomato
seedlings are usually transplanted 3 -
6 weeks after planting in the nursery
beds (FAO, 2013). Transplanting was
done in row at plants spacing of 30
cm between plant and 30cm between
rows and the plants population per
plot was approximately 80, giving
3,840 tomato stands for the entire
fourty-eight (48) experimental plots.
Fertilizer (Di-ammonium phosphate
fertilizer (NPK 15:15:15)) was
applied two weeks after transplanting
and weeding. The fertilizers and
the rates of application were as
recommended by FAO (2013).
The mulch materials, except white
polyethylene materials, were
placed two weeks after transplanted
tomatoes were fully established.
The white polyethylene materials
were cut into size (3 m x 3 m) and
placed over the entire basin on
the day of transplanting, precisely
before transplanting. Holes were
created in accordance with the plant
spacing and the tomato seedlings
were passed through the holes. The
average weight of rice straw and
wood shaving mulch spread in each
of the plots (with rice straw and
wood shaving treatment) were 1.2
kg and 2.25kg respectively because
the amount is sufciently enough
to cover the plot area. Weeding was
done three times on plots with mulch
and without mulch treatments,
while no weeding was carried out
on plots with white polyethylene
mulch material after transplanting.
Systemic insecticide (Cypermathrin)
was applied on weekly basis at early
owering stage and then at 3-day
interval during mid to maturity
stages. This is to enable less damage
to the crop fruits from disease and
pests.
Irrigation water application
Surface irrigation method was

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adopted. Water was released from the
secondary canal into a tertiary ditch
that conveys the water to the eld
ditches via a siphon and eventually
served the basins. A 75 mm diameter
PVC tube of approximately 2m
length was installed in each basin
to admit water into the basins. The
PVC tubes were installed through
the embankment of each basin with
one end in the eld ditch and the
other end in the basin. The tubes
were installed to give a free orice
ow into the basins. Stage gauges
were placed at the water inlet of each
basin to measure the depth of water
over each tube as water enters the
basin. PVC corks were placed at the
entrance such that when the corks
were removed, water ows into the
basins. When the desired depth of
water was applied, the PVC corks
were also used to stop the ow of
water into the plot. Using the orice
ow equation stated below (Equation
3) and the depth of ow recorded
from the stage gauge, the ow rates
into each basin were determined
and related to time of application to
give to each plot the desired depth of
water application. The time required
to apply the depth of water was
monitored using a stop watch.
The amount of water applied at every
irrigation event (weekly interval)
was observed throughout the crop
growing season) and was based on
the reference evapotranspiration
amount for that week of irrigation
and the experimental treatment.
Kgh
d
KghAAVKQ ××






=××== 2
2
2
2
π
(Nally, 2013) (3)
Where, Q = ow in cubic meter
per second (m3/sec), A = area of
the orice in square meters (m2), V
= velocity of the liquid in meters
per second (m/sec), K = 0.82
Constant for tube, g = 9.81 m/sec2
= Acceleration due to gravity in
meter per square second (m/sec2), h
= Head across the orice in meters
(m), d = diameter of the orice in
meters (m),
But it should be noted that;
WRETA×=Volume
(m3) (4)
Where A= area of plot = 2.5 x
2.5mm =6.25 mm2 and WRET=

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weekly reference evapotranspiration
(mm/week)
Also,
tQ ×=Volume
(m3)
(5)
Q
Volume
t=∴
(6)
Where t= time (i.e. duration for
irrigation) (sec.)
Soil Moisture Measurement
The soil moisture status of the
experimental eld was monitored
throughout the crop growing season
using soil moisture meter. The soil
moisture meter was used to monitor
the soil moisture at 0 - 20, 20 - 40,
40 - 60 and 60 - 80 cm depths.
Soil moisture measurements were
carried out twice a week, at two days
after irrigation and on the seventh
day (just before the next irrigation).
It is assumed that most soil will
attain eld capacity two days after
irrigation.
Crop Water Requirement (ETc)
The crop water use between
successive moisture measurements
was estimated using the soil moisture
depletion method (Igbadun and
Oiganji, 2012), with the expression
given in Equation 7.
( )
t
DAMCMC
CWU
n
i
isiii
∑
−
××−
=
1
21
(7)
where, CWU is average daily
crop consumptive use between
successive soil moisture content
sampling periods (mm/day); MC1i
is soil moisture content (g/g) at the
time of rst sampling (2 days after
irrigation) in the ith soil layer; MC2i
is soil moisture content (g/g) at the
time of second sampling (7 days
after irrigation) in the ith layer; Asi is
bulk density (g/cm3) of the ith layer;
Di is thickness of ith layer (mm); ‘n’
is number of soil layers sampled
in the root zone depth D, and ‘t’ is
number of days between successive
soil moisture content sampling.
The weekly consumptive use was
obtained as the product of the daily
crop consumptive use between
successive soil moisture content
sampling and the number of days
in the week while the seasonal crop
water use is the summation of the
weekly CWU. The crop consumptive
use of the treatments irrigated at
100% WRET (with or without
mulch), was regarded as actual
consumptive use while the CWU of

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the decit irrigated treatments (I80,
I60 and I40) was regarded as decit
consumptive use (CWUdecit).
Computation of Water Stress
Coefcient (Ks)
The water stress coefcient (Ks)
integrates the crop and soil factors
that make the actual crop water use
of the decit irrigated condition
differ from crop water use under fully
irrigated condition. The relationship
is expressed as:
CWUKsCWU
deficit
×=
(8)
Where, Ks is water stress coefcient;
other parameters were as previously
dened.
Note that:
EToKcCWU ×=
and
EToKcCWU deficitdeficit ×=
EToKcKsCWU
deficit
××=∴
(Igbadun and Oiganji, 2012)
(9)
And by substitution and
simplication:
Kc
Kc
Ks
deficit
=
(10)
The values of Kc, Kcdecit and Ks
for the four growth stages of the
crop were computed by nding the
averages of the weekly coefcient
values for the growth stages.
Tomato Maturity and Computation
of Crop Yield
The tomato crop began to show signs
of maturity by changing of colour
from greenish to reddish at 10 weeks
after transplanting. Harvesting was
carried out about four weeks effective
from 4th April to 2nd May, 2014.
Harvesting was done by plugging
the ripped tomato fruits and labelled
according to the treatment applied to
the plots and then weighed.
The crop yield was computed for
each of the experimental plot in
accordance with Igbadun et al.
(2012) using Equation 11.
( )
2
/mkg
A
W
Y=
(11)
Where Y is the crop yield (kg/m2), W
is the weight of harvested tomatoes
(kg) and A is the plot area of the
harvested tomatoes (m2)

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RESULTS AND DISCUSSION
Soil of the experimental site
The soil of the site was found to
have an average bulk density of 1.3
g/cm3 and average moisture content
of 25.12% (Table 2).
Table 2: Bulk density and initial soil moisture content of the experimental
site.
Soil
depth
(cm)
Mass of wet
soil+tin
Mw (g)
Mass of oven
dried soil+tin
Ms (g)
Mass of tin
Mt (g)
Bulk density
(g/cm3)
Pb
Moisture
Content
(%dwb*)
0 - 20 277.6 261.0 177.92 1.1 19.9
20 - 40 310.5 287.3 189.11 1.3 23.63
40 - 60 315.4 287.7 189.51 1.3 28.21
60 - 80 323.3 292.9 187.16 1.4 28.75
Average 1.3 25.12
* dwb = Dry weight basis
Daily crop water use
The result of daily crop water use
ranged from 1.67 to 11.41 mm/day
across the treatments as indicated
on Table 3. A comparison of the
daily crop water use on the basis of
irrigation treatment indicated that
daily crop water use decreased with
increase in decit irrigation. The
average peak crop water use of the
treatments given full irrigation (I100)
was 7.99 mm/day. The average peak
crop water use of the decit irrigated
treatments (that is, I80 (20% decit),
I60 (40% decit), and I40 (60%
decit)) were 7.66, 5.21 and 3.51
mm/day, respectively and all the
peak values were obtained in the no-
mulch treatments of the experiment.
The decrease in daily crop water use
due to decit irrigation ranged from
about 20 to 40% with the highest
values in the range occurring at I40
(60% decit) treatments. The mode of
decrease in crop water use as a result
of decit irrigation was expected
since the amount of water available
in the soil for plant uptake reduces
with decit irrigation. However, the
study reveals that applying water
at 80% (20% decit) of reference
evapotranspiration (ETo) reduces

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peak crop water use of the tomato
crop by about 10%. More so, if water
is applied at 40% (60% decit) of
ETo, the peak consumptive use of
the tomato crop will be reduced by
about 56%. A comparison of the
daily crop water use as inuenced by
mulching shows that the daily CWU
of the no mulch (NM) treatments
ranged from 2.45 to 11.41 mm/day
across irrigation regimes, while the
average daily CWU of the mulched
treatments ranged from 1.67 to
10.8 mm/day across irrigation
regimes. However, the trend of the
daily CWU was carefully studied
and this reveals that, the daily crop
water use was more pronounced
in the developmental and fruit
formation stages of growth, most
especially the NM treatments among
other mulch treatments. Observed
among the mulched treatments
were the rice straw mulch (RSM)
treatments, which were found to be
higher than other mulch treatments,
consequently, wood shaving mulch
(WSM) followed and lastly by white
polyethylene mulch (WPM). The
average peak crop water use of the
NM treatments was noticed to be
higher than the RSM treatment by
7.3 - 60% across the treatments, with
higher value in the range occurring at
higher irrigation decit. The average
peak crop water use of the RSM was
also found to be higher than the other
mulched treatments by 13.4 to 65.5%
across the other mulch treatments.
Higher CWU in the NM treatments
compared to the mulched treatments
at establishment to maturity-harvest
growth stages can be attributed
to the inuence of direct surface
evaporation since the soil cover was
exposed to the atmosphere.

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Table 3: Average daily crop water use of the tomato crop (mm/day)
Treatment
Growth stage
Establishment Development Fruit formation Maturity-Harvest
Days after transplanting
2
– 9
10 –
16
17 –
23
24 –
30
31 –
37
38 –
44
45 –
51
52 –
58
59 –
65
66 –
72
73 –
79
80 –
86
87 –
93
94 -
100
I100 5.45 5.73 6.96 7.39 7.48 7.61 11.01 10.80 11.41 10.49 7.09 7.25 6.60 6.54
NM I80 5.10 5.31 6.46 6.90 7.05 7.39 10.50 10.38 11.01 10.29 6.95 7.03 6.40 6.47
I60 3.86 4.02 5.01 5.41 5.47 5.87 5.59 5.64 5.97 5.41 5.46 5.47 4.90 4.90
I40 2.45 2.61 3.41 3.64 3.61 3.72 4.92 3.72 3.92 3.53 3.64 3.53 3.17 3.29
I100 4.98 5.26 6.55 6.99 7.08 7.18 9.76 10.16 10.80 9.67 6.46 6.76 6.05 5.99
RSM I80 4.77 5.05 6.41 6.93 6.79 6.98 9.24 9.85 10.49 9.36 6.34 6.62 5.99 5.84
I60 3.71 3.87 5.02 5.44 5.33 5.49 4.89 5.30 5.52 4.90 4.85 5.14 4.57 4.57
I40 2.43 2.62 3.30 3.59 3.55 3.58 3.13 3.49 3.60 3.29 3.26 3.29 2.94 3.07
I100 4.69 4.90 6.20 6.66 6.79 6.91 9.24 9.65 10.40 9.27 6.19 6.49 5.84 5.77
WSM I80 4.55 4.61 6.00 6.37 6.38 6.77 8.93 8.82 10.19 8.85 6.13 6.30 5.70 5.63
I60 3.52 3.64 4.69 4.99 5.06 5.30 4.79 4.72 5.42 4.80 4.85 4.69 4.39 4.45
I40 2.34 2.46 3.19 3.31 3.44 3.54 3.22 3.01 3.61 3.27 3.22 3.15 2.79 2.83
I100 4.10 4.39 5.64 6.09 6.15 6.35 8.53 8.84 9.58 8.34 5.63 5.93 5.22 5.14
WPM I80 3.89 4.33 5.35 5.80 5.86 6.07 8.43 8.65 9.38 8.03 5.57 5.65 5.14 5.07
I60 3.05 3.40 4.23 4.53 4.52 4.63 4.45 4.63 5.03 4.35 4.34 4.41 4.00 4.00
I40 2.06 2.30 2.83 1.69 1.67 1.73 2.94 3.15 3.27 2.95 2.87 2.95 2.71 2.71

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Seasonal applied water and
seasonal crop water used
Table 4 shows the seasonal applied
water (SAW) and seasonal crop
water use (SCWU) for both full and
decit irrigations. The SAW ranged
from 362.92 to 907.28 mm while
the SCWU was found to be between
250.73 and 782.60 mm. The result of
SCWU of fully irrigated treatment for
NM (782 mm) and RSM (725 mm)
obtained from the study, however,
disagrees with that reported by
Mohammad et al., (2013) who gave
SCWU of 540.42 and 671.57 mm
but the fully irrigated treatment for
WSM (692.83 mm) and WPM (629
mm) closely agrees with Mohammad
et al., (2013) result. The least value
in the range was obtained in the I40
(60% decit) treatments with WPM,
while the highest value in the range
was recorded in the I100 treatment
with NM. FAO, (2013a) reported
that water requirement for optimum
tomato yield is between 400 and 600
mm depth. The SCWU values of
the I100 and I80 of all the treatments
were found to be higher than the
range stated by FAO, (2013a)
except the I80 of WPM was within
FAO (2013a) water requirement
range; this may have resulted from
late growing season of the tomato
crop in the experimental site which
supposed to be between November
and February instead of January to
April. However, the SCWU of I60 of
all treatments was found to be within
FAO (2013a) water requirement
but the I40 treatments was below the
lower class range of FAO (2013a)
water requirement. It was observed
that the SAW of I100 and I80 treatments
were above the upper range stated by
FAO, (2013a) but the I60 and I40 of the
treatments are within FAO (2013a)
water requirement range. Moreover,
the SAW of I40 of all treatments was
also found to be below the lower
class range of the FAO (2013a)
water requirement as this can be seen
on Table 4. Meanwhile, the result
of SCWU for all treatments agrees

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with that given by FAO, (2013b)
who reported that the SCWU varies
from 400 to 800 mm, depending
on climatic conditions of the study
area. Analysis of variance (ANOVA)
test was conducted using statistical
analysis for science (SAS) software
and this indicated that there were
highly signicant differences (p <
0.01) in the means of SCWU of the
irrigation (water application depths)
treatments, there were also highly
signicant differences (p < 0.01)
among the mulch treatments. The
interaction between irrigation and
mulching was also highly signicant
(p < 0.01). The results imply that
seasonal crop water use (SCWU) was
largely inuenced by both the water
application depth and mulching. The
nuence of water application depths
on seasonal crop water use was
expected since evapotranspiration
is very much dependent on water
supply and availability within the
plant root zone. Evidence of higher
seasonal applied water (SAW)
associated with I100 and I80 treatments
may be due to the treatment schedule
of this study which was based on
reference evapotranspiration (ETo)
and late growing season of the crop
on the experimental site, which gives higher water application depth per
irrigation compared to crop water used.
Table 4: Seasonal applied water and seasonal crop water used
Treatment
SWA SCWU
(mm) (mm)
I100 907.28 782.60
NM I80 725.82 719.75
I60 544.36 510.75
I40 362.92 344.03
I100 907.28 725.87
RSM I80 725.82 704.63

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I60 544.36 480.06
I40 362.92 316.01
I100 907.28 692.83
WSM I80 725.82 666.62
I60 544.36 457.15
I40 362.92 303.64
I100 907.28 629.37
WPM I80 725.82 610.64
I60 544.36 417.06
I40 362.92 250.73
Crop Yield
Table 5 shows the total yields of
tomato and mean yield harvested in
the experimental eld. The total mean
yields ranged from 6.91 to 23.98 t/
ha with an annual averages of 11.48,
18.48, 11.98 and13.33 t/ ha for NM,
RSM, WSM and WPM treatments
respectively. The least yield was
obtained from the I40Mwsm treatment,
while the highest yield was obtained
from the I60Mrsm treatment. It was
expected that the least irrigated
treatments (I40) will produce the
lowest yield while the fully irrigated
treatments (I100) will produce the
highest yield since tomato crop is
known to be responsive to water,
also high yield was expected
from WPM which is known to
increase soil temperature thereby
improving the yield compared to
other treatments but this is not the
real case, hence this may be due to
lack of weeding effect as compared
to other treatments where weeding
was carried out three times before
harvest. The least irrigated treatment
(I40) had the least yield of 6.91 t/

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ha while the 40% decit irrigated
treatment (I60) had the highest yield
of 23.98 t/ha. However, statistical
analysis showed highly signicant
difference among the yield obtained
where I80 ranked as the highest while
I40 as the least. Moreover, statistical
signicant difference was noticed
between seasonal crop water use
values of the treatments. There
were highly signicant differences
(p < 0.01) among the irrigation
treatments and the mulch treatments
with least signicant difference
(LSD) of 0.2111. The interaction
between irrigation and mulching was
also highly signicant. This pattern
of result was noticed both in the
mulched and no-mulch treatments,
which implies that irrespective of
mulching, water application depth
signicantly inuences tomato yield,
and this agrees with FAO (2013) who
reported that tomato yield decreased
with increase in water decit. The
result of statistical analysis suggests
that water application depth per
irrigation may be reduced to 80%
of ETo water demand without
causing a signicant loss in yield
of tomato crop. However, the yield
of the rice straw mulch statistically
ranked highest corresponding to the
irrigation water level of I80 and the
yield was also signicantly different
from the yields of the other mulch
treatments and No-mulch treatments.
These results imply that mulching
signicantly inuences soil water

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conservation of irrigated tomato crops as well as seasonal crop water use
(Patil et al., 2013).
Table 5: Total and mean yields of tomato (ton/ha)
Treatment Replicate 1 Replicate 2 Replicate
3Mean
I100Mnm
NM
14.91 15.47 15.52 15.30
I80Mnm 11.66 11.70 11.60 11.65
I60Mnm 10.19 10.37 10.64 10.40
I40Mnm 8.29 8.45 8.99 8.58
Annual average 11.48
I100Mrsm
RSM
18.59 18.85 18.85 18.76
I80Mrsm 22.08 21.90 21.95 21.98
I60Mrsm 23.98 23.49 23.55 23.67
I40Mrsm 9.92 9.44 9.12 9.49
Annual average 18.48
I100Mwsm
WSM
16.66 16.90 16.85 16.80
I80Mwsm 14.06 14.18 14.11 14.12
I60Mwsm 9.78 9.57 10.72 10.02
I40Mwsm 7.15 6.91 6.86 6.98
Annual average 11.98

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I100Mwpm
WPM
11.55 11.71 11.63 11.63
I80Mwpm 15.62 15.70 15.55 15.62
I60Mwpm 15.65 15.81 15.92 15.79
I40Mwpm 10.26 10.19 10.38 10.28
Annual average 13.33
Water Stress Coefcients
Table 6 shows the water stress
coefcients (Ks) values. The
seasonal average (SA) values are also
indicated in the table. The Ks values
of the four growth stages ranged from
0.46 to 0.98 across the treatments
and seasons, while the seasonal
average, Ks ranged from 0.55 to
0.97. It is necessary to note that Ks
values generally ranged from zero
(absolute water stress in which there
is no evapotranspiration at all and
the plant withers) to 1.00 (no water
stress in which evapotranspiration is
at maximum) as reported by Igbadun
and Oiganji (2012). Igbadun and
Oiganji (2012) further reported that
the water stress coefcients can be
classied on the basis of its impact
on seasonal crop water use as: critical
(0.1< Ks ≤ 0.5), severe (0.51< Ks ≤
0.75), moderate (0.76 < Ks ≤ 0.90)
and minor (0.91 < Ks ≤ 0.99). Based
on this background, it can be said
that the water stress coefcient of the
I80 treatments, irrespective of mulch
management practice, was minor. It
can be observed from the table that
irrespective of mulch management
practice, the water stress coefcients
of I40 and I60 at maturity to harvest
stage were moderate but from establishment to fruit formation stage I60
treatments mingled between severe and moderate. However, the water stress
coefcients of the I40 treatments, irrespective of mulch management practice,
were critical from establishment to fruit formation except WPM which shows
variation and had severe effect. The seasonal average, Ks of the I80 treatments
was also minor while that of I60 and I40 treatments were moderate and severe,
respectively.
Table 6: Water stress coefcients (Ks) of tomato crop

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Treatments Growth stages
Establishment
Development
Fruit
formation
Maturity
-Harvest
Seasonal
Average
I80 0.93 0.94 0.97 0.98 0.96
NM I60 0.72 0.76 0.74 0.89 0.78
I40 0.49 0.50 0.48 0.79 0.55
I80 0.96 0.98 0.96 0.98 0.97
RSM I60 0.77 0.76 0.76 0.90 0.79
I40 0.50 0.50 0.49 0.80 0.58
I80 0.96 0.96 0.95 0.98 0.96
WSM I60 0.76 0.71 0.75 0.90 0.79
I40 0.51 0.46 0.48 0.78 0.58
I80 0.97 0.95 0.98 0.98 0.97
WPM I60 0.75 0.77 0.77 0.91 0.80
I40 0.50 0.52 0.52 0.83 0.55
Effect of Decit Irrigation and
Mulch on Yield and Crop Water
Use
Table 7 shows the statistical analysis
using Statistical Analysis Software
(SAS) of the main effects of decit
irrigation and mulching practices on
yield and crop water use of tomato.
The analysis shows that the effect
of various levels of irrigation and
mulching practices was found to be
highly signicant (**) at 5% level
of signicance. This means that
both decit irrigation and mulching
practices of tomato crop have
signicant effect on the yield of the
crop. The table also presented the
result of the analysis that compared
the various irrigation levels as well as
the different mulching practices and
found to be highly signicant (**) at

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5% level of signicance. This also
means that both decit irrigation,
irrespective of the level and
mulching practices, has signicant
effect on yield and crop water use of
tomato grown in the study area. The
interaction between the irrigation (I)
and mulching practices (M); (I*M)
was also found to be highly signicant (**) at 5% level of signicance.
This result further reveals that the best level of irrigating tomato crop at the
experimental site is at I80 giving mean yield of 15.84 t/ha at mean crop water
use of 675.40 mm/season corresponding to mulching practice of rice straw
mulch (RSM).
Table 7: Statistical analysis of effect of decit irrigation, mulch and their
interaction on yield and crop water used
Treatment y c
I
I100 15.62b 707.70a
I80 15.84a 675.40b
I60 14.97c 466.30c
I40 8.83d 303.60d
signicance ** **
LSD (5%) 0.2111 0.00
M
NM 11.48d 589.30a
RSM 18.48a 556.60b
WSM 11.98c 530.10c
WPM 13.33b 476.90d
Signicance ** **
LSD (5%) 0.2111 0.00
Interaction

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I x M ** **
** = Highly signicance at 5% I
=Irrigation NM = No mulch y =
yield M = Mulch
RSM = Rice straw mulch c = crop water
used WSM = Wood shaving mulch WPM
= White polyethylene mulch
Conclusion
Base on iled and water use of tomato
under decit irrigation and mulch
practices carried out in KRIP, the
following conclusion were drawn:
 The total mean yields ranged
from 6.98 to 23.67 t/ha with an
annual average of 11.48, 18.48, 11.98
and13.33 t/ ha for NM, RSM, WSM
and WPM treatments respectively.
The SAW ranged from 362.92 to
907.28 mm while the SCWU was
found to be between 250.73 and
782.60 mm.
 The least value in the range
was obtained in the I40 (60% decit)
treatments with WPM, while the
highest value in the range was
recorded in the I100 treatment with
NM. FAO, (2013a) has reported
that water requirement for optimum
tomato yield is between 400 and 600
mm depth.
 There were highly signicant
differences (p < 0.01) in the means
of SCWU of the irrigation (water
application depths) treatments,
there were also highly signicant
differences (p < 0.01) among the
mulch treatments.
 The interaction between
irrigation and mulching was also
highly signicant (p < 0.01).
 The inuence of water
application depths on seasonal
crop water use was expected since
evapotranspiration was very much
dependent on water supply and
availability within the plant root
zone.
 The statistical analysis shows
that the effect of various levels of
irrigation and mulching practices
were found to be highly signicant.
 Both decit irrigation,
irrespective of the level, and
mulching practices have signicant
effect on yield and crop water use of
tomato grown in the study area.

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 The best level of irrigating tomato crop at the experimental site is at I80
giving mean yield of 15.84 t/ha at mean crop water use of 675.40 mm/season
and this corresponds to mulching practice of rice straw mulch (RSM).
References
Ayana M. (2011). Decit irrigation practices as alternative means of improving water use
efciencies in irrigated agriculture: Case study of maize crop at Arba Minch, Ethiopia.
African Journal of Agricultural Research Vol. 6(2), pp. 226-235. Available online at http://
www.academicjournals.org/AJAR
Bekele S. K. Tilahun, (2007). Regulated decit irrigation scheduling of onion in a semi arid
region of Ethiopia. Journal of Elsevier. Available online at http://www.elsevier.com/locate/agwat
Bodunde J.G. (1998) Yield and yield related characteristics of tomato plants as
indices of irrigation efciency in conventional ridgeside and basin plant placement
under high environmental temperature. Proc. 16th Hortson conference 7 – 10th
September 1998, Abeokuta.
FAO, (2013). Water Development and Management -Crop Water Information Tomato, Food
and Agriculture Organization, Rome. http://www.fao.org/nr/water/cropinfo_tomato.html
FAO , (2013a). Water Development and Management - Crop Water Information Tomato,
Food and Agriculture Organization (FAO), Rome. http://www.fao.org/nr/water/cropinfo_
tomato.html
FAO, (2013b). Irrigation Water Management: Irrigation water needs. Natural Resources
Management and Environment Department. http://www.fao.org/docrep/s2022e/s2022e07.htm
Grossman, R.B. and T.G. Reinsch, (2002). Bulk Density and Linear Extensibility. In: Methods
of Soil Analysis. Part 4. Physical Methods, Dane, J.H. and G.C. Topp (Eds.). ASA and SSSA,
Madison, WI, pp: 201-228.
Igbadun, H.E and Oiganji, E. (2012). Crop coefcients and yield response factors for onion
(Allium Cepa. L) under decit irrigation and mulch practices in Samaru, N i g e r i a .
African Journal of Agricultural Research.
Igbadun, H.E., A. A. Ramalan, E. Oiganji, (2012). Effects of regulated decit irrigation and
mulch on yield, water use and crop water productivity of onion in Samaru, Nigeria.

388
Red sea university Journal of Basic and Applied Science
Vol. 2 Special Issue (1) - March 2017
ISSN: 1858 -7690 (Online)
ISSN: 1858 -7658 (Print)
Journal of Agricultural Water Management. www.elsevier.com/locate/agwat
Jibrin, J.M., S.Z. Abubakar and A. Suleiman, (2008). Soil Fertility Status of the Kano River
Irrigation Project Area in the Sudan Savanna of Nigeria. Journal of Applied Sciences, 8:692-
696. DOI:10.3923/jas.2008.692.696 URL: http://scialert.net/abstract/?doi=jas.2008.692.696
24th July, 2013.
Maina, M.M., Amin, AM.S.M., Aimrun, W. and Sani I. (2012). Soil Salinity Assessment of
Kadawa Irrigation of the Kano River Irrigation Project. Journal of Food, Agriculture and
Environment, Vol. 10(3&4). WFL Publisher, Helsinki, Finland
Michael, A.M. and T.P. Ojha, (2005). Principle of Agricultural Engineering. Volume II. Jain
Brothers Publication, New Delhi, India.
Mohammad, F.S., Al-Ghobari, H.M. and El Marazky, M.S.A. (2013). Adoption of an
intelligent irrigation scheduling technique and its effect on water use efciency for tomato
crops in arid regions. Journal of crop science. Australia. AJCS 7(3):305-313 (2013)
ISSN:1835-2707
Nally, Mc., (2013). Approximate ow through an orice. The Mc Nally Institute Book
division, Dade city, Florida. Retrieved from:
http://www.mcnallyinstitute.com/13-html/13-12.htm
Olorunaiye E. S. (2009). Evaluation of Selected Crop – yield Water Use models for tomato
(lycopersicon esculentum) under moisture stress conditions. Agricultural Engineering,
Faculty of Engineering, Ahmadu Bello University, Zaria, Nigeria. An MSc. thesis.
Oyinlola E.Y. and S. Akintoye (2004) Response of irrigated tomato to Boron
fertilizer (Nigeria Journal of Soil Sc. 5:53 – 61).
Patil Shirish S., Kelkar Tushar S. and Bhalerao Satish A. (2013). Mulching: A Soil and Water
Conservation Practice. Research Journal of Agriculture and Forestry Sciences. India. Vol.
1(3), 26-29.
Quim, J.G. (1980). A review of tomato cultivars trials in the Northern states of
Nigeria Samaru Miscellaneous paper 84.
Thimme, G. P., Manjunaththa, S. B., Yogesh, T. C., & Sunil, A. S. (2013). Study on