Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
781
CROP WATER AND IRRIGATION WATER REQUIREMENTS OF
MAIZE (ZEA MAYS L.) IN THE ENTISOLS OF KUWAIT
M. Abdul Salam a and Suad Al Mazrooei b
a
Department of Biological Sciences, College of Science, Kuwait University,
PO Box 5969, Safat 13060, State of Kuwait
E-mail: [email protected]
b
Department of Biological Sciences, College of Science, Kuwait University,
PO Box 5969, Safat 13060, State of Kuwait
E-mail: [email protected]
ABSTRACT
Crop water and irrigation water requirements of maize were estimated using the FAO
CROPWAT model for the loamy sands of Kuwait. Agro-meteorological data 0f 43
years was used for this purpose. The crop water requirement (ETc), irrigation
requirement (IR) and net irrigation requirement (NIR) of maize vary with the planting
date. Water use of grain maize was the lowest with planting date of 5th November. The
period 25th October to 5th December is suitable for maize planting. The ETc of grain
maize varied from 210 mm for a 90 day crop to 273 mm for a 110 day crop with
planting date 5th November. The IR of grain maize varied from 126 mm for a 90 day
crop to 179 mm for a 110 day crop with same planting date. The NIR varied from
1226 m3 ha-1 for a 90 day crop to 1898 m3 ha-1 for 110 day crop with planting date 5th
November. Grain maize planting may not be advanced beyond 5th December, in order
to economise the water use. Water use of sweet corn (60 days) was the lowest with
planting date of 5th December. The period 5th November to 15th December is suitable
for sweet corn planting. ETc of sweet corn ranged from 125 mm (5th December
planting) to 182 mm (15th October planting). The IR of sweet corn, ranged from 66mm
(5th December planting) to 148 mm (15th October planting). The NIR of sweet corn
was 532 m3 ha-1 with planting date 5th December. Sweet corn planting may not be
advanced beyond 15th December, in order to economise the water use. An irrigation
schedule was also developed for grain maize and sweet corn for the loamy sands of
Kuwait.
Keywords: ETc, irrigation, maize, sandy loam soils, water requirements
INTRODUCTION
Kuwait (located at 30o 27’ N, 48 o 46’ E) is one of the smallest countries of the Middle
East. Soils are mostly entisols with low water-holding capacity and susceptibility to
wind erosion. The clay and organic matter content is low indicating poor soil fertility.
782
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
Calcareous nature in some areas and salinity problems in certain other areas pose
problems for agricultural use. Kuwait Institute of Scientific Research (KISR), after a
detailed soil survey reported that 2.71 percent of the total land area is suitable for
agriculture and are located at Al Wafra, Al Abdali and along the western margin of
Kuwait City (KISR, 1999).
Not much work has been done in Kuwait to develop agricultural production
technologies. With the beginning of agricultural practices, growers look for scientific
aspects of crop production including irrigation. Date palm, potato, barley and maize
forms the most important crops grown under open field conditions under irrigation.
Being an extremely dry environment with harsh climate and poor soils, agriculture
without irrigation is rather impossible. Water use efficiency in irrigated agriculture
assumes greater significance particularly in semi arid environments with increasing
pressure on water resources from competitive users (Hatfield et al., 1996). Information
on scientific irrigation scheduling is meager for crops of Kuwait. Indirect methods
using evapotranspiration measurements are widely used to develop irrigation
schedules in many countries.
Reference crop evapotranspiration (ETo) is evapotranspiration rate from a reference
surface, not short of water. It expresses the evaporating power of the atmosphere at a
specific location and time of the year and does not consider the crop characteristics
and soil factors. Reference crop evapotranspiration is also known as potential
evapotranspiration
(ETo)
(http://www.fao.org/docrep/X0490e/x0490e04.htm).
Evaporation and transpiration of a crop can be related to the ETo of the area as it is
independent of factors other than climate. As such the information on ETo of an area
will be a very useful guide for development of irrigation schedules for crops.
There are different approaches in developing irrigation schedule. One method is the
“water balance” or “soil water budget” approach which involves keeping an account of
water input into the soil (rainfall and irrigation) and water output (evapotranspiration
and drainage) on daily basis. Measurements of rainfall and irrigation may be easy but
estimation of ET and drainage involves complex procedures. In many parts of the
world, irrigation is scheduled by use of a class ‘A’ evaporation pan (Doorenbos, 1976).
This is a 1.21m (4 ft) diameter circular pan filled with water. The daily rate of
evaporation from the pan is determined from the change in water level adjusted for
rainfall. But the pan evaporation may be 25 to 100 percent more than ETo depending
on location of the pan and the weather conditions. The important weather data required
for the estimation of (ETo) are air temperature, humidity, wind speed and sunshine
hours. A computer program (Hess, 1996) or a spread sheet (Hess and Stephens, 1993)
can be used to calculate ETo using the Penman or Penman-Monteith equation. This
method has been shown to be reliable in a wide range of environments (Allen et al.,
1994). Most water balance irrigation schedule methods are based on a daily estimate of
the reference evapotranspiration (ETo) which is then modified according to the type of
crop, stages of growth and soil water content (Hess, 1996). He further reported that
Penman-Monteith equation should give the best estimate of ETo where daily weather
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
783
data are available. Allen (1998) reports guidelines for computing crop water
requirements based on evapotranspiration.
Though several models have been proposed to predict ETo, there is no universal
consensus on the suitability of any given model for a given climate, there by
prompting (Smith et al., 1996) to conclude that these models require rigorous local
calibration before they can be used for the estimation of ETo for irrigation scheduling.
The local calibration and validation are more important in semi-arid environment than
temperate, because almost all the ETo models were developed, calibrated, and
validated for temperate environment using reliable and long term weather data
(Ventura et al., 1999, Allen et al., 1998, Smith et al., 1996 and Jensen et al., 1990).
For local calibration, the methodology published first in 1974 as Bulletin no.24 in the
FAO (fao-24) Irrigation and Drainage series and revised in 1977 (Doorenbos and
Pruitt, 1977), is widely followed internationally. Penman model frequently
overestimated ETo, while the other models showed variable adherence to grass
reference. Further, the FAO-24 method assessed for a humid temperate environment in
Tottori, Japan (Yano and Hayashi, 1977), using long-term weather data (1952-1974),
indicated that Penman and Radiation balance models produced similar ETo estimates. .
Recent studies have raised few concerns about the FAO-24 methodology (Jensen et al.,
1990, Allen et al., 1989, Batchelor, 1984). The ETo estimates obtained from six
commonly used ETo estimation models indicates that Penman-Monteith method
produced the most reliable estimates, compared to lysimeter data, for the semi-arid
Karaj region, in Iran (Hossein et al., 2004).
Spatial distribution of potential evapotranspiration in the Indus river basin of Pakistan
was estimated by Ullah et al., (2001) by using Penman-Monteith equation. The upper
and northern part of the basin has lower reference evapotranspiration (1200-1300mm)
because of mild climate, whereas the lower part of the basin, Southern Punjab and
Sindh has much higher ETo values (1700-2100mm). Simulated and recorded values
of evapotranspiration and DM yield ranged from 150mm and 1 t ha-1 to 700m and
22 t ha-1 (Grant, 1990)
METHODOLOGY
a. Collection of climatological data
The climatic data such as air temperature, air humidity, rainfall, pan evaporation, wind
speed and sunshine hours recorded at the Kuwait International Airport (KIA) were
used for the study. The mean data of 1962-2004 period (43 years) was used for
estimation of ETo and water use.
784
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
b. Collection of soil data
Kuwait Institute of Scientific Research (KISR) conducted a detailed soil survey of
Kuwait and published the results. Soil data such as available water holding capacity,
soil depth, bulk density, texture etc. were collected from this soil survey report (KISR,
1999).
c. Crop data
During the growth span, the crop passes through various phases and stages of growth.
Accordingly the crop demands varying quantities of water, depending on growth stage.
In the case of maize, the duration of growth phase depends on the duration of the
variety. For example, a 90 day variety can have 20 days as initial growth phase,
20 days as development phase, 20 days as mid phase and 30 days as late or maturity
phase (Table 1). A 100 day variety can have 20 days as initial growth phase, 25 days
as development phase, 25 days as mid phase and 30 days as late or maturity phase
(Table 2) and for a 110 day variety have 25 days as initial growth phase, 25 days as
development phase, 30 days as mid phase and 30 days as late or maturity phase
(Table 3). The relationship between crop evapotranspiration (ETc) and reference
evapotranspiration (ETo) is given by the crop coefficient (Kc), which is 0.30 for initial
phase, 1.20 for development and mid phases and 0.50 for late phase. The rooting depth
for the initial and developmental phases was taken as 0.30m and mid and late phases
as 1.10m.
d. Estimation of water requirements
The reference crop evapotranspiration (ETo), crop water requirement (ETc), irrigation
requirement (IR), net irrigation requirement (NIR) effective rainfall (ER) and
irrigation schedule (IS) of maize were estimated using the FAO Penman-Monteith
method using the CROPWAT decision support system. (Doorenbos and Pruit, 1977).
Calculations of crop water requirements and irrigation water requirements are carried
out with inputs of climatic, soil and crop data. The development of irrigation schedule
is based on a daily soil-water balance. The crop evapotranspiration under standard
conditions, denoted as ETc, is the evapotranspiration from disease-free, well-fertilized
crops, grown in large fields, under optimum soil water conditions, and achieving full
production under the given climatic conditions. ETc is estimated as a product of ETo
and Kc.
ETc = ETo x Kc
Where Kc = Crop coefficient
The irrigation requirements (IR) were estimated as difference between crop water
requirement and effective rainfall (calculated based on data on rainfall and soil
characters of Kuwait).
IR = ETc – ER
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
785
Effective rainfall is that fraction of the total rainfall that forms part of the consumptive
use of the crop. It was estimated by the procedure suggested by Doorenbos and Pruit
(1977). The term net irrigation requirement (NIR) refers to the actual quantity of water
that is to be applied to the soil as irrigation water.
The term irrigation schedule (IS) refers to the quantity and frequency of irrigation of a
crop during its growing season. The Irrigation schedules are developed based on
available water holding capacity of the soil, duration of the crop, duration of the
growth phase and crop coefficients for different growth stages.
RESULTS AND DISCUSSION
Climate
Kuwait climate is characterized by extremely high temperature during summer, short
mild winters, high sunshine hours, low humidity and general dry conditions. The mean
monthly data of weather parameters of 43 years (1962-2004) were calculated and used
for the study. The average daily maximum temperature varies from 18.7oC during
January to 46.1oC (July). The average daily minimum temperature varies from 7.8oC
during January to 29.4oC during July. The average daily temperature ranges from
13.2oC during January to 38.5oC during July.
The total annual rainfall of the area is 138 mm of which 133 mm forms effective. This
rainfall is being received mostly from December to April. December and January are
the months receiving highest amount of rainfall. Practically, there is no rain during
summer. Rain-fed agriculture is not possible in Kuwait because of the extreme scarcity
of rainfall. The daily mean ETo varies from 2.75 mm d-1 during January to 14.03 mm
d-1 during June. The mean Relative humidity ranges from 17.7 percent during July to
65 percent during January. May to October forms the dry period and November to
April forms the cool period.
The wind speed ranges from 252.3 km d-1 during October to 437.2 km d-1 during June.
The prevailing winds in Kuwait are from the northwest and the southeast. In the
summer months between June and September, the monsoon depression affects the
northwesterly winds, which form 59 percent of the total wind (Khalaf, 1989). Dust and
sand storms are typical of Kuwait and occur through out the year. However, according
to Khalaf and Al Ajmi (1993), they are more frequent in spring and mid summer
(March to August). The mean sunshine hours ranges from 6.2 h/day during December
to 11.1 h day-1 during June. Solar radiation ranges from 11.3 MJ m2 d-1 during
December to 26.7 MJ m2 d-1 during June.
Soils
Soils of Kuwait vary considerably with respect to their physical and chemical
properties. This study was focusing to the agricultural soils of Wafra where maize is
786
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
being grown under open field conditions. The surface soil has depth ranging from 40
cm to 60 cm and restricting layers were not seen up to 1.0 m depth. The clay content
of the soil varies from 4.1 to 10 percent, silt content varies from 2.7 to 21 percent and
sand content varies from 87.9 to 93.2 percent. The bulk density of the soil ranges from
1.83 g cm-3 to 1.88 g cm-3. The moisture content of the soil at field capacity is 9 to 10
percent and at permanent wilting point 3 to 4 percent. The available water holding
capacity varies from 5 to 7 percent. The pH of the soil varies from 7.8 to 8 percent and
the electrical conductivity (EC) varies from 0.3 to 1.5 d S m-1. (KISR, 1999).
REFERENCE CROP EVAPOTRANSPIRATION (ETO)
The ETo values vary from 2.75 mm d-1 during January to 14.03 mm d-1 during June.
The total annual ETo is estimated as 2882.5 mm. The results indicate that the
evapotranspiration demand of Kuwait environment is very high. Being an arid
environment with high temperature, wind speed and solar radiation, it is natural that
the ETo values are high compared to the other regions. As ETo plays a vital role to
decide the ETc of a crop, it is probable that the water requirements of crops in this
region could be relatively high. Ullah et al., 2001 reported the potential
evapotranspiration in the Indus river basin in Pakistan as 1200mm to 1300mm in the
upper and northern part of the basin and 1700 mm to 2100 mm in the lowest part of the
basin. The high ETo values in Kuwait are mainly due to the harsh weather conditions.
In line with the ETo pattern, the ETc requirements will also be high. Therefore it
would be sensible to choose periods of low ETo in the annual cycle, for agricultural
activities.
Effective rainfall (ER)
Of the total annual rainfall of 138 mm, 133 mm forms effective. This fraction can
contribute to the consumptive use of the crop. Because of the extreme inadequacy of
rainfall, it is difficult to adopt agriculture without irrigation in this environment.
Crop water requirement (ETc)
Crop water requirement is the quantity of water needed for normal growth,
development and yield and may be supplied by precipitation or by irrigation or by
both. The water requirement of a crop is dependent upon, crop factors (like variety,
growth stage, duration, plant population and growing season), soil factors (like texture,
structure, depth, and topography), climatic factors (like temperature, relative humidity
and wind velocity) and crop management practices (like tillage, fertilization, weeding
etc.).
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
787
Grain maize
The crop water requirement (ETc) of grain maize was worked out for nine different
planting dates at ten days interval commencing from the 15th October to 5th January
(Table 2, 3 and 4). This was done for varieties of different duration (90, 100 and 110
days) (Figure 1, 2 and 3). The ETc of a 90 day variety range from 210 mm (5th
November planting) to 323 mm (5th January planting). Similarly the ETc of a 100 day
variety ranged from 244 mm (5th November planting) to 398 mm (5th January
planting). The ETc of a 110 day variety range from 273 mm (5th November planting)
to 470 mm (5th January planting). ETc values were lowest with planting date 5th
November and highest with planting date 5th January. ETc of grain maize is generally
low with planting dates from 25th October to 5th December, suggesting that this period
is the right time for grain maize planting in Kuwait.
Sweet corn
The crop water requirement (ETc) of sweet corn (60 days) was worked out for nine
different planting dates at ten days interval commencing from the 15th of October to 5th
of January (Table 5). For sweet corn of 60 days duration, the lowest ETc was 125 mm
(5th December planting) and highest 182 mm (15th October planting) (Figure 4). ETc
of sweet corn is generally low with planting dates from 5th November to 15th
December, suggesting that this period is the right time for sweet corn planting in
Kuwait.
Irrigation requirement (IR)
The IR basically represents the difference between the crop water requirement and
effective precipitation. The irrigation water requirement also includes additional water
for leaching of salts and to compensate for non-uniformity of water application. The
IR of a 90 day variety ranged from 126 mm (5th November planting) to 270 mm (5th
January planting) whereas that of a 100 day variety ranged from 155 mm (5th
November planting) to 341 mm (5th January planting). The IR of a110 day variety
ranged from 179 mm (5th November planting) to 411 mm (5th January planting). IR of
maize is generally low with planting dates from 25th October to 5th December,
suggesting that this period is the right time for maize planting.
The IR of a sweet corn ranged from 66 mm (5th December planting) to 148 mm (15th
October planting). IR of sweet corn is generally low with planting dates from 5th
November to 5th December, suggesting that this period is the right time for sweet corn
planting.
Net Irrigation requirement (NIR)
The term net irrigation refers to the actual quantity of water that is to be applied to the
soil as irrigation water. The NIR of a 90 day variety ranged from 123 mm (5th
November planting) to 267 mm (5th January planting) whereas that of a 100 day
788
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
variety ranged from 151 mm (5th November planting) to 333 mm (5th January
planting). The NIR of a110 day variety ranged from 178 mm (5th November planting)
to 408 mm (5th January planting). The NIR of a sweet corn (60 days) ranged from 53
mm (25th November and 5th December planting) to 146 mm (15th October planting).
Variation in ETc and NIR in relation to duration of the variety
ETc and NIR of maize varieties varied with duration. Both ETc and NIR increases
with increasing duration of the variety. The ETc of a 90 day variety was 210 mm (5th
November planting) (Figure 1), whereas the same for 110 day variety was 273 mm
(Figure 3) with the same planting date. The corresponding NIR values are 123 mm and
178 mm. It is quite natural that the ETc, IR and NIR increases with increase in the
duration.
Irrigation scheduling
The irrigation scheduling for grain maize of varying duration (90, 100 and 110 days),
with planting date 5th November is shown in table 6, 7 and 8. For a 90 day crop with
planting date 5th November, it requires 5 irrigations with interval ranging from 10 to 20
days. In total, it requires 1226 m3 of water per hectare per season (Table 6). For a 100
day crop with planting date 5th November, it requires 6 irrigations with irrigation
interval of 12 to 20 days. The crop requires 1509 m3 of water per hectare per season
(Table 7). For a 110 day duration variety, it requires 7 irrigations at an interval of 10 to
31 days and the total water requirement of the crop is 1898 m3 per hectare per season
(Table 8). The crop with planting date 5th November enjoys the cool period of the year
as well as the rainy season and thus, the ETc, IR, and NIR are very low.
For sweet corn of 60 day duration with planting date 5th December, it requires two
irrigations. First irrigation 40 days after planting and second 11 day there after and the
total NIR is 532 m3 of water per hectare per season (Table 9).
CONCLUSIONS
From the present study it is clear that a planting-window from 25th October to 5th
December can be safely considered for grain maize planting. The study also indicates
that it is not advisable to go for maize planting after December. For sweet corn a
planting window of 5th November to 5th December would be ideal. Proper timing of
maize planting is important to achieve higher water use efficiency. Detailed field
experiments are necessary to assess the effect of planting dates on maize yield and
water use efficiency, keeping the present study as a base.
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
789
ACKNOWLEDGEMENTS
This work was supported by Kuwait University research grant no. (SL 03/05). The
authors are grateful to Kuwait Institute of Scientific Research and Kuwait International
Airport for the climatological data. Thanks are also due to Food and Agriculture
Organization (FAO) for providing the CROPWAT decision support system. We also
thank the Research Administration Kuwait University, the Dean, College of Science,
the Department Research Committee and the Chairman, Department of Biological
Science for all the support extended for this study.
NOMENCLATURE
ETo
ETc
TR
ER
IR
NIR
= Reference crop Evaporation - mm
= Crop Water Requirement - mm
= Total Rain fall - mm
= Effective Rainfall - mm
= Irrigation Requirement - mm
= Net Irrigation Requirement - mm
REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
Allen, R.G., Jensen, M.E., Wright, J.L. and Burman, R.D. 1989. Operational
estimates of evapotranspiration. Agron. J. 81: pp650-662.
Allen, R.G., Smith, M., Perrier, A. and Pereira, L.S. 1994. An update for the
definition of reference evapotranspiration. ICID Bulletin, 43: 1-34.
Allen, R.G. Pereira, L.S., Raes, D., Smith, M. 1998. “Crop evapotranspirationGuidelines for computing crop water requirements- FAO irrigation and drainage
paper 56”, Food and Agric Org of UNO, Rome, Italy.
Batchelor, C.H. 1984. The accuracy of evapotranspiration functions estimated
with the FAO modified penman equation .J. Irrigation Sci. 4-5, pp. 223-234.
Doorenbos, J., Pruitt, W.O., and Doorenbos, J. 1976. Agro-meteorological
field stations (FAO irrigation and Drainage paper 27). Food and Agriculture
Organisation of the United Nations (FAO) Rome.
Doorenbos, J. and Pruitt, W.O. 1977. Guidelines for predicting crop water
requirements. (FAO Irrigation and drainage paper 24). Food and Agriculture
Organisation of the United Nations (FAO) Rome, Italy. 144.
Grant, R.F. 1990. Dynamic simulation of water deficit effects upon maize yield.
Agricultural systems 33: 1, 13-39; 28.
Hatfield, J.L., Prueger, J.H., and Reicosky, D.C. 1996. Evapotranspiration
effects on water quality. In: Proceeding of the ASAE International Conference on
Evapotranspiration and Irrigation scheduling, 3-6 November, San Antonio, TX,
pp. 536-546.
Hess, T.M. 1996. Evapotranspiration estimates for water balance scheduling in
the UK. Irrigation News, 25: 31-36.
790
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
10. Hess, T.M. and Stephens, W. 1993. The Penman equation. D. H. Noble & C. P.
Course (Editors), Spreadsheets in Agriculture. (pp.184-194). Longman Scientific
and Technical.
11. Hossein, D.S., Tahei, Y. and Rasiah, V. 2004. Assessment of evapotranspiration
estimation models for use in semi-arid environments.
http://www.fao.org/docrep/X0490e/x0490e04.htm
12. Jensen, M.E., Burman, R.D., and Allen, R.G. 1990. Evapotranspiration and
irrigation water requirement. ASAE Manuals Rep. Eng. Pract. 70, p.332.
13. Khalaf, F.I. and Al Ajmi, D. 1993. Aeolian process and sand encroachment
problems in Kuwait. Geomorphology 6: 111-134.
14. Khalaf, F.I. 1989. Desertification and Aeolian processes in the Kuwait desert.
Journal of Arid Environments 16: 125-145.
15. KISR. 1999. Kuwait Institute of Scientific Research – Soil Survey for the state of
Kuwait Volume II. Reconnaissance Survey, AACM International Adelaide,
Australia. ISBN 0 957700326.
16. Smith, M., Allen, R.G., and Pereira, L.S. 1996. Revised FAO methodology for
crop water requirements. In: Proceeding of the ASAE International Conference
on Evapotranspiration and Irrigation scheduling, 3-6 November, San Antonio,
TX, pp.116-123.
17. Ullah, M.K., Habib, Z., and Muhammad, S. 2001. Spatial distribution of
reference and potential evapo-transpiration across the Indus Basin Irrigation
Systems. Lahore, Pakistan: International Water Management Institute (IWMI
working paper 24).
18. Ventura, F., Spano, D., Duce, P., and Snyder, R.L. 1999. An evaluation of
common evapotranspiration equations. J. Irrigation Sci. 18, pp. 163-170.
19. Yano, T. and Hayashi, Y. 1977. Evaporation in a sand dune area estimation of
potential evapotranspiration by routine meteorological data. Bull. Sand Dune Res.
Inst., Tottori Univ. 16, pp. 1-7 (in Japanese).
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
791
Table 1 Crop data of maize
Growth stages
Stage length (days)
Crop coefficients (Kc)
Rooting depth (m)
Depletion levels (P)
Yield factors (Ky)
Initial
Development
Mid
Late
20
20
25
20
0.30
0.30
0.50
0.40
20
25
25
20
1.20
0.30
0.50
0.40
20
25
30
19
1.20
1.10
0.50
1.30
30
30
30
1
0.50
1.10
0.80
1.50
Total duration
(d)
90
100
110
60
3.60
Table 2 ETo, ETc, IR and NIR of grain maize of 90 days duration
Date of
planting
15th October
25th October
5th November
15th November
25th November
5th December
15th December
25th December
5th January
ETo
mm/period
362
323
292
287
282
291
320
349
390
ETc
mm/period
254
228
210
211
215
228
254
285
323
Rainfall mm/period
TR
ER
70
67
81
77
89
84
88
83
87
82
83
79
76
73
70
67
62
59
IR
mm/period
187
152
126
129
137
155
187
224
270
NIR
mm/period
177
140
123
127
114
149
173
206
267
Table 3 ETo, ETc, IR and NIR of grain maize of 100 days duration
Date of
planting
15th October
25th October
5th November
15th November
25th November
5th December
15th December
25th December
5th January
ETo
mm/period
389
351
330
325
328
348
377
412
468
ETc
mm/period
277
254
244
247
258
281
311
348
398
Rainfall mm/period
TR
ER
82
78
92
87
93
89
92
88
91
87
88
84
82
78
74
71
66
63
IR
mm/period
199
167
155
159
174
203
239
283
341
NIR
mm/period
169
163
151
164
173
179
228
255
333
792
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
Table 4 ETo, ETc, IR and NIR of grain maize of 110 days duration
Date of
planting
15th October
25th October
5th November
15th November
25th November
5th December
15th December
25th December
5th January
ETo
mm/period
418
390
368
371
385
404
440
491
547
ETc
mm/period
292
277
273
284
305
332
370
417
470
Rainfall mm/period
TR
ER
93
88
96
92
98
93
97
92
96
92
93
89
86
82
78
75
69
67
IR
mm/period
203
185
179
194
219
259
295
349
411
NIR
mm/period
187
190
190
178
201
224
280
354
408
Table 5 ETo, ETc, IR and NIR of sweet corn of 60 days duration
Date of
planting
15th October
25th October
5th November
15th November
25th November
5th December
15th December
25th December
5th January
ETo
mm/period
279
240
207
191
175
168
179
189
210
ETc
mm/period
182
157
138
131
126
125
138
151
171
Rainfall mm/period
TR
ER
35
34
46
43
55
52
61
58
67
63
69
65
62
59
55
52
47
45
IR
mm/period
148
114
85
75
67
66
85
105
132
Table 6 Irrigation scheduling for grain maize (90 days duration)
planted on 5th November in the loamy sands of Kuwait
Date of irrigation
19/11
9/12
19/12
29/12
14/1
3/2
Total
Irrigation interval
(days)
14
20
10
10
16
20
90
NIR
(m3/ha)
137
241
262
275
311
Date of harvest
1226
NIR
mm/period
146
110
92
64
53
53
78
104
129
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
Table 7 Irrigation scheduling for grain maize (100 days duration)
planted on 5th November in the loamy sands of Kuwait
Date of irrigation
19/11
9/12
22/12
3/1
15/1
3/2
13/2
Total
Irrigation interval
(days)
14
20
13
12
12
19
10
100
NIR
(m3/ha)
137
209
271
258
277
358
Date of harvest
1509
Table 8 Irrigation scheduling for grain maize (110 days duration)
planted on 5th November in the loamy sands of Kuwait
Date of irrigation
18/11
19/12
29/12
10/1
20/1
2/2
17/2
23/2
Total
Irrigation interval
(days)
13
31
10
12
10
13
15
6
110
NIR
(m3/ha)
124
253
265
280
272
326
379
Date of harvest
1898
Table 9 Irrigation scheduling for sweet corn (60 days duration)
planted on 5th December in the loamy sands of Kuwait
Date of irrigation
14/1
25/1
3/2
Total
Irrigation interval
(days)
40
11
9
60
NIR
(m3/ha)
260
272
Date of harvest
532
793
794
179
15th December
377
228
25th December
412
255
468
5th January
333
5th November
210
123
15th November
211
127
25th November
215
114
5th December
228
149
15th December
254
173
25th December
285
206
323
5th January
267
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
348
140
Fig 1. ETc and NIR of maize of 90 day duration in Kuwait
5th December
228
25th October
ETc
173
254
177
NIR
328
25th November
15th October
350
164
300
325
250
15th November
ETc
NIR
151
200
330
150
5th November
mm
163
100
351
25th October
50
169
0
389
Fig2. ETc and NIR of Maize of 100 day duration in Kuwait
500
450
400
350
300
mm 250
200
150
100
50
0
15th October
78
25th December
151
104
171
5th January
129
5th November
273
190
15th November
284
178
25th November
305
201
5th December
332
224
15th December
370
280
25th December
417
354
470
5th January
408
Tenth International Water Technology Conference, IWTC10 2006, Alexandria, Egypt
138
190
Fig 3. ETc and NIR of maize of 110day duration in Kuwait
15th December
277
25th October
ETc
53
292
187
NIR
125
500
5th December
450
53
400
126
25th November
15th October
350
64
300
131
ETc
15th November
NIR
92
mm 250
138
200
5th November
150
110
100
157
25th October
50
146
0
182
Fig 4. ETc and NIR of sweet corn of 60 day duration in Kuwait
200
180
160
140
120
mm 100
80
60
40
20
0
15th October
795