1. Hybrid Irrigation Method for Improving Surface Irrigation
Efficiencies and Crop Water Productivity
Abdrabbo A. A. Shehata Aboukheira, Associate Research Professor,
Ahmed M. Abdel-Fatah, Researcher, Youssri Atta, Research Professor
Water Management Research Institute (WMRI), National Water Research Center (NWRC)
Address: NWRC’s Premises P. O. 13621/5, Delta Barrage, Kaliobiya, Egypt
Voice: (+202) 42189458, Fax: (+202) 42189561, E-mail: abdo23870@gmail.com
Executive Summary: Egypt has a large and growing population currently estimated at
over 90 million and expected to rise to exceed 140 million by the year 2050 if present
growth rates continue. The country is almost entirely desert with virtually no rainfall. The
country’s renewable water resources are restricted to the flow of the Nile River,
although there is limited exploitation of non-renewable underground water in the oases
of the Western Desert. Egypt’s share of the Nile River flow is governed by a treaty
signed with its southern neighbor Sudan in 1959 and set at 55.5 billion cubic meters per
year. Since the national water supply is fixed at this amount, continued population
growth inevitably means increasing national water scarcity, and Egypt is already well
under the international standard of 1,000 cubic meters per person per year. Over 85%
of the annual water supply is devoted to agricultural production, and Egyptian farmers
practice on of the most intensified forms of irrigated agriculture in the world, achieving
global records for yield per hectare in a number of major food crops. Despite impressive
gains in the 1980s and 1990s, agricultural production has not kept pace with population
growth, and Egypt has a net food import bill of over $6 billion.
In Egypt, under limited water supply conditions, providing additional resources will be an
expensive option. Therefore, efforts in the optimal management of water resources
should concentrate on the demand management side. As the agricultural sector is
consuming the bulk of water supply, good management of irrigation water can be
translated into significant amount of saving in the water resources. In addition, the
agriculture sector will be most affected by water shortage and would be asked to give
water to other uses such as the domestic and the industrial sectors. Consequently,
increasing the efficient use of water in the agricultural sector would be an overarching
goal in changing certain policies or adopting new technologies with the objectives of
improving on-farm water management and maximizing agricultural return per unit of
water.
In the 2.31 million ha of the old lands of the Nile Valley and Delta, most farmers still use
primitive methods of irrigation, fertilization, and weed and pest control practices. The
application of fertilizers is usually by hand with low efficiency, resulting in higher costs
and environmental problems. Surface irrigation is typically practiced in short furrows
surrounded by small basins for irrigating most crops, except those such as rice that are
grown in ponded water. This method is inefficient in the following respects: (1) Water is

2. used excessively because flowrates are not uniform; (2) Labor is wasted in construction
of checks, furrows and water manipulation; (3) 10 - 20% of land is wasted in borders,
furrow ends and small canals; and (4) Poor uniformity and distribution of irrigation water
results in waterlogging, salinization, and low distribution and application efficiencies of
surface irrigation (35-65%) in the Nile Valley and Delta. In the last two decades,
replacing surface irrigation with precise irrigation systems became the main interest of
the decision makers and policy planners in Egypt. Land fragmentation, capital and
operating costs, profitability, and the need to qualified labors are the main challenges of
converting from surface to pressurized irrigation systems. Surface irrigation systems
can be as efficient as most other irrigation methods. To achieve the high efficiency and
uniformity of surface irrigation systems, all parts of an irrigated field should receive
water for near equal period of time, with a minimum of water lost to runoff or to deep
percolation below the root zone. In addition to several practices, land smoothing, reuse
of tailwater (i.e., reuse of water that runs off the downstream end of surface irrigated
fields), cutback irrigation, and surge-flow irrigation can be employed to improve the
effectiveness of surface irrigation. Best management practices and strategies improved
the efficiencies of surface irrigation but still below level compared with pressurized
irrigation methods, so looking for innovative ideas and highly efficient improvements for
surface irrigation modernization is an urgent need.
Rice is the staple food for nearly half the earth’s population. Irrigated rice cultivation
claims more than half of the water extracted for human activities in different regions of
the world. One kilogram production of rice in irrigated fields consumes 2 to over 5 m3 of
water, while the theoretical minimum at the crop scale is as low as 0.6 m3. The
traditional practice of permanently flooding rice fields increases breeding habitats for
malaria vectors. Particularly, rice has become one of the most important Egyptian
exports in the agricultural sector. Rice cultivated area is growing gradually in the Nile
Delta. It increased from about 280,000 ha by the mid-70’s to about 0.8 million ha in
2013. This rapid increase in rice cultivation has resulted from increasing its profitability
compared to other crops. The drastic increase in water use in rice cultivation is
augmenting the pressure on water supplies; it consumes about 29-50% of the total
water budget of Egypt, and threatens to undermine the availability of water for
reclaiming new lands.
This case study presents the first findings of an ongoing research to develop and
evaluate an innovative irrigation method named “hybrid irrigation method”. The new
method is a compromised solution to overcome the disadvantages of surface and
pressurized irrigation methods. These first findings are the optimum plot area per outlet
for irrigating wheat, raised-bed management practices of rice and corn under hybrid
irrigation method in clay soil of the east Nile Delta of Egypt, and the feasibility of using
hybrid irrigation method for irrigating rice and vegetable gardens for food security and
rural income sustainability in Mali and sub-Saharan Africa.
The theory of hybrid irrigation method is to maximize water distribution efficiency as
much as of pressurized irrigation systems by using a network of pipelines which
decrease water losses by eliminating evaporation, deep percolation, surface run-off,
and seepage, that occurs under normal conditions of surface irrigation using earthen

3. ditches. Moreover, application efficiency was modified by delivering water under
pressure inside the field plot to minimize advance time, which results in decreasing
water losses and ensuring that the depths and discharge variations over the field are
relatively uniform and, as a result, available soil water in the root zone is also uniform.
Hybrid irrigation is accomplished by causing water to flow under pressure over the land
surface through the same components of sprinkler or microirrigation irrigation networks
(mainlines, sub-mainlines, and manifolds; except the lateral lines and distributors which
replaced by outlets, each outlet is designated for irrigating a certain field plot). The
outlets are devices that release water from high-head pipelines into basins, borders,
and furrows (i.e., in the multi-outlet hybrid irrigation system, the outlets consist of a riser
pipe and one or more valves to control the flow). The outlets should release into fields
without causing erosion. They may include alfalfa or orchard valves, various types of
hydrants, gated pipes, perforated pipes, different sizes of hoses, etc. Seven irrigation
systems could be classified as hybrid irrigation systems, which are multiple-inlet, multi-
outlet, simulated LEPA (Low Energy Precision Application), low-head bubbler, micro-
flood, perforated pipes, and gated pipes irrigation systems.
Hybrid irrigation systems design begin when the desired combination of irrigation time,
stream size, inflow time, basin dimensions, and the number of basins irrigated per set
have been identified. In this regard, a field experiment was conducted to examine the
optimum irrigated area per outlet of the multi-outlet hybrid irrigation system for irrigating
wheat in the clay soil of the east Nile Delta of Egypt during the winter season of
2007/2008. Three irrigated areas per outlet (350, 525, and 700 m2) were studied. The
results revealed that increasing the irrigated area per outlet from 350 to 700 m2
increased advance time from 4.7 to 12.1 min/outlet, respectively. In addition, increasing
the irrigated area per outlet by 100% from 350 to 700 m2 increased total applied water
from 3580 to 3970 m3/ha and decreased crop water productivity from 0.99 to 0.86
kg/m3, respectively. In general, application efficiency modified for all treatments as much
as the average application efficiency of sprinkler irrigation systems (82-84%). In
particular, application efficiency decreased by increasing the irrigated area per outlet
from 350 to 700 m2 (84-82%), respectively. The results concluded that the optimum
irrigated area per outlet is 350 m2 because it decreased water losses in the root zone
and optimized water use.
Two field experiments were conducted in clay soil of the east Nile Delta of Egypt to
investigate the optimum raised-bed width using the multi-outlet hybrid irrigation system
for irrigating corn and rice crops. First, a 2‐year field experiment (2005-2006) was
conducted to examine the effect of raised-bed width (80 and 160 cm) compared with
traditional furrow irrigation on corn production. The results revealed that water saving
(30 and 54%), grain yield (6 and 9%), and crop water productivity (52 and 131%) were
increased by increasing the width of the raised bed under the multi-outlet hybrid
irrigation system (80 and 160 cm) compared with traditional furrow irrigation,
respectively. Second experiment was conducted on rice cultivation with two different
width of raised-bed (60 and 80 cm) compared with traditional furrow irrigation during two
summer seasons of 2006 and 2007. The interactive effect of raised-bed and the multi-
outlet hybrid irrigation system saved water by 33 and 38%, increased paddy yield by 4

4. and 6%, and, as a result, improved crop water productivity by 56 and 75% with the 60
and 80 cm width of the raised-bed technology compared to the traditional furrow
irrigation. The results concluded that the wider raised-beds (160 and 80 cm) are the
most efficient and profitable for corn and rice, respectively, due to improving soil water
availability redistribution in the root zone.
A feasibility study was carried out to evaluate the profitability of applying the multi-outlet
hybrid irrigation system for irrigating rice and vegetable gardens in Mali and sub-
Saharan Africa in 2011. The study indicated that the advantage of the multi-outlet hybrid
irrigation system over gravity irrigation system for rice production is about US $ 1062.
On the other hand, the multi-outlet hybrid irrigation system increased the net income of
producing onion by 80% compared to manual irrigation by jugs. Furthermore, for both
crops, the multi-outlet hybrid irrigation system changed the opportunity of agricultural
production from mono-crop to multi-crop system in three consecutive seasons per year
by increasing the cultivated areas per family and controlling irrigation and drainage
water.
In Egypt, the multi-outlet hybrid irrigation system was adopted by the irrigation sector of
the Ministry of Water Resources and Irrigation and the Ministry of Agriculture and Land
Reclamation to be implemented at large scale level and to be the new model of the
Irrigation Improvement Project in the west Nile Delta of Egypt. The innovative system
was implemented in about 504 ha on Neckla Canal at El-Beheira Governorate in the
east Nile Delta and the plan is to use the multi-outlet hybrid irrigation system model in
all ongoing and future irrigation improvement projects around the country. In addition,
some orchard producers were adopted the system for irrigating about 3.8 ha of citrus
trees in the east Nile Delta.
Ultimately, first findings of field experiments and the feasibility study concluded that the
hybrid irrigation method is optimizing water use and maximizing yield compared with
surface irrigation and pressurized irrigation methods. The hybrid irrigation method saves
water, energy, fertilizers, and money; moreover, increases yield of rice, corn, and
vegetables and farmer’s income; in addition, it protects the environment and decreases
health risk. Therefore, the hybrid irrigation method should be adopted and expanded for
achieving food security and rural income sustainability in arid and semi-arid areas, as
well as depressed areas in Sub-Saharan Africa.
Keywords: Surface irrigation, distribution and application efficiencies, Mali, Egypt,
raised-bed, rice, corn, wheat, feasibility study, vegetables, advance time, pressurized
irrigation