6
the growing season (Fernandes-Silva et al. 2018) is one of these strategies. Regulated
deficit irrigation is another strategy contributes in water saving and low yield losses
(Capra et al. 2008). This strategy is divided into stage-base deficit irrigation and
partial-root system irrigation (Chai, et al. 2016). Moreover, precise irrigation scheduling is crucial for regulated deficit irrigation, which aims to induce a mild water
stress to the plant to save water and improve crop yield (Jones 2004). Maintaining
optimum crop yield under water deficit conditions has stimulated researchers to
explore new irrigation technology, systems, and strategies to improve water use
efficiency and water productivity (Fernandes-Silva et al. 2018).
1.5 Climate Change, Water Scarcity and Food Security
Global and regional climates have already begun changing. Climate change is
directly or indirectly attributed to human activity that alters the composition of the
global atmosphere, in addition to natural climate variability observed over comparable time periods (Karmakar et al. 2016). The models that describe global climate
are mathematical representations of physical and dynamical processes to simulate
the interaction within and in between the atmosphere, land surface, oceans and sea
ice (Dettinger 2005). IPCC (2007) reported that “the global atmospheric concentration of carbon dioxide, methane and nitrous oxide has increased from pre-industrial
era to 2005. The annual carbon dioxide concentration growth rate was larger during
the last 10 years’ average (1995–2005, 1.9 ppm per year), than it has been since the
beginning of continuous direct atmospheric measurements (1960–2005, average 1.4
ppm per year) although there is year-to-year variability in growth rates”. In order to
limit global warning in 2100 to 2 °C above pre-industrial levels, annual emissions
from the agricultural sector must be reduced by 1 giga ton of carbon dioxide equivalents per year by 2030 (Wollenberg et al. 2016). Currently available interventions,
such as sustainable intensification of dairy production and alternate wetting and
drying in irrigated rice to achieve emission efficiencies will be necessary, as well as
innovative policies to promote sequestering soil carbon (Cole et al. 2018).
The Fourth Assessment Report of the Intergovernmental Panel on Climate
Change (IPCC 2013) stated that “the magnitude of stress on water resources is
expected to increase as a consequence of climate change, in addition to future population growth and urbanization as a consequence of land-use change”. According to
the scenarios described in the IPCC Special Report on Emissions Scenarios, changes
in precipitation and temperature may lead to changes in runoff and water availability (Cisneros et al. 2014). Previous research projected that climate change will
intensify and accelerate the hydrological cycle, which will result in more water
being available in some parts of the world and less water being available in other
parts of the world (most of the developing world) (IPCC 2013). Weather patterns are
predicted to be more extreme. The regions adversely affected by climate change will
experience droughts and/or possible flooding, which could affect food production
S. Ouda and A. E.-H. Zohry
the growing season (Fernandes-Silva et al. 2018) is one of these strategies. Regulated
deficit irrigation is another strategy contributes in water saving and low yield losses
(Capra et al. 2008). This strategy is divided into stage-base deficit irrigation and
partial-root system irrigation (Chai, et al. 2016). Moreover, precise irrigation scheduling is crucial for regulated deficit irrigation, which aims to induce a mild water
stress to the plant to save water and improve crop yield (Jones 2004). Maintaining
optimum crop yield under water deficit conditions has stimulated researchers to
explore new irrigation technology, systems, and strategies to improve water use
efficiency and water productivity (Fernandes-Silva et al. 2018).
1.5 Climate Change, Water Scarcity and Food Security
Global and regional climates have already begun changing. Climate change is
directly or indirectly attributed to human activity that alters the composition of the
global atmosphere, in addition to natural climate variability observed over comparable time periods (Karmakar et al. 2016). The models that describe global climate
are mathematical representations of physical and dynamical processes to simulate
the interaction within and in between the atmosphere, land surface, oceans and sea
ice (Dettinger 2005). IPCC (2007) reported that “the global atmospheric concentration of carbon dioxide, methane and nitrous oxide has increased from pre-industrial
era to 2005. The annual carbon dioxide concentration growth rate was larger during
the last 10 years’ average (1995–2005, 1.9 ppm per year), than it has been since the
beginning of continuous direct atmospheric measurements (1960–2005, average 1.4
ppm per year) although there is year-to-year variability in growth rates”. In order to
limit global warning in 2100 to 2 °C above pre-industrial levels, annual emissions
from the agricultural sector must be reduced by 1 giga ton of carbon dioxide equivalents per year by 2030 (Wollenberg et al. 2016). Currently available interventions,
such as sustainable intensification of dairy production and alternate wetting and
drying in irrigated rice to achieve emission efficiencies will be necessary, as well as
innovative policies to promote sequestering soil carbon (Cole et al. 2018).
The Fourth Assessment Report of the Intergovernmental Panel on Climate
Change (IPCC 2013) stated that “the magnitude of stress on water resources is
expected to increase as a consequence of climate change, in addition to future population growth and urbanization as a consequence of land-use change”. According to
the scenarios described in the IPCC Special Report on Emissions Scenarios, changes
in precipitation and temperature may lead to changes in runoff and water availability (Cisneros et al. 2014). Previous research projected that climate change will
intensify and accelerate the hydrological cycle, which will result in more water
being available in some parts of the world and less water being available in other
parts of the world (most of the developing world) (IPCC 2013). Weather patterns are
predicted to be more extreme. The regions adversely affected by climate change will
experience droughts and/or possible flooding, which could affect food production
S. Ouda and A. E.-H. Zohry