8
E.-S. E. Omran and A. M. Negm
high temperature and accumulating of carbonates and soluble salts in desert soils,
and the other inhabiting in alluvial soils in the Nile Delta and the Qattara Depression
of the Western desert. Soil microbial activity will affect by climate change directly
or indirectly. These effects include increasing temperature, elevated or increasing the
concentration of CO 2 , rise changing soil moisture content, increasing of soil salinity,
and drought. The activity of soil microorganism and/or enzyme is significant as
a sensitive indicator of soil biological quality. These activities are informative to
determine changes in soil biochemical properties that are affected by environmental
stress from natural phenomena or anthropogenic activities. Bacteria and fungi living
in the soil control the breakdown of organic matter in the soil and its release into
the atmosphere as carbon dioxide [6]. Climate warming is expected to increase soil
microbe development, promote more CO 2 release, as well as positive climate change
feedback. A better understanding of microbial processes is likely to improve climate
change predictions [7]. Recent research has therefore attempted to quantify the impact
of warming on soil microbes and the carbon cycle processes they control and to
explain this using efficiency metrics such as microbial carbon [6].
The third chapter under the current theme is titled “Soils as Driver and Victim
of Climate Change in Egypt”. This chapter explains how the soil can act as a driver
and Victim of climate change. Agricultural soil is an important driver of GHG emissions. Emissions from clay soils are higher compared to sandy soils, especially in the
presence of high moisture and organic matter contents and high pH that encourage
CO 2 and N 2 O flux. Global warming increases CO 2 emissions with an exponential
relationship by increasing the temperature of the surface layer of agricultural soils.
Nitrogen fertilizers are a major source of N 2 O emissions both in dry soils due to
nitrification process or denitrification in waterlogged soils as well as methane emissions in rice fields. In Egypt, about 25 million tons of rice husk and sugarcane wastes
are burned in open field, which contributes strongly to climate change.
On the other hand, agricultural land is a victim of climate change as the global
warming accelerates the breakdown of soil organic matter, which reduces soil fertility, water storage, and microbial activity, destroys soil structure and increases their
susceptibility to soil compaction. The surface layer of soil is expected to lose about
55 million tons of carbon by the year 2050. Egypt’s agricultural land is experiencing
increased drought throughout the country. Northern coasts of the Delta are intruded
by rising sea level, and salt-affected soils cover about 10% of the Delta area.
On the other hand, the chapter titled “Soil Carbon Sequestration for Climate
Change Mitigation: Some Implications to Egypt” show how in carefully managed
croplands, soil C sequestration can be substantial and represents a potentially constructive portion for mitigating the increased levels of atmospheric CO 2 . The soil is
the largest terrestrial carbon (C) stock, and those factors that affect C retention and
release also influence on atmospheric CO 2 levels. Soil C sequestration represents
about 90% of the total mitigation practices of climate change and about 10% of
emission reduction. There is a great concern of soil carbon (C) sequestration and its
role in absorbing atmospheric CO 2 not only because of its impacts on climate change
mitigation but also because of its positive impacts on the sustainability of crop productivity, soil fertility, and soil quality. Cultivation has resulted in considerable loss
E.-S. E. Omran and A. M. Negm
high temperature and accumulating of carbonates and soluble salts in desert soils,
and the other inhabiting in alluvial soils in the Nile Delta and the Qattara Depression
of the Western desert. Soil microbial activity will affect by climate change directly
or indirectly. These effects include increasing temperature, elevated or increasing the
concentration of CO 2 , rise changing soil moisture content, increasing of soil salinity,
and drought. The activity of soil microorganism and/or enzyme is significant as
a sensitive indicator of soil biological quality. These activities are informative to
determine changes in soil biochemical properties that are affected by environmental
stress from natural phenomena or anthropogenic activities. Bacteria and fungi living
in the soil control the breakdown of organic matter in the soil and its release into
the atmosphere as carbon dioxide [6]. Climate warming is expected to increase soil
microbe development, promote more CO 2 release, as well as positive climate change
feedback. A better understanding of microbial processes is likely to improve climate
change predictions [7]. Recent research has therefore attempted to quantify the impact
of warming on soil microbes and the carbon cycle processes they control and to
explain this using efficiency metrics such as microbial carbon [6].
The third chapter under the current theme is titled “Soils as Driver and Victim
of Climate Change in Egypt”. This chapter explains how the soil can act as a driver
and Victim of climate change. Agricultural soil is an important driver of GHG emissions. Emissions from clay soils are higher compared to sandy soils, especially in the
presence of high moisture and organic matter contents and high pH that encourage
CO 2 and N 2 O flux. Global warming increases CO 2 emissions with an exponential
relationship by increasing the temperature of the surface layer of agricultural soils.
Nitrogen fertilizers are a major source of N 2 O emissions both in dry soils due to
nitrification process or denitrification in waterlogged soils as well as methane emissions in rice fields. In Egypt, about 25 million tons of rice husk and sugarcane wastes
are burned in open field, which contributes strongly to climate change.
On the other hand, agricultural land is a victim of climate change as the global
warming accelerates the breakdown of soil organic matter, which reduces soil fertility, water storage, and microbial activity, destroys soil structure and increases their
susceptibility to soil compaction. The surface layer of soil is expected to lose about
55 million tons of carbon by the year 2050. Egypt’s agricultural land is experiencing
increased drought throughout the country. Northern coasts of the Delta are intruded
by rising sea level, and salt-affected soils cover about 10% of the Delta area.
On the other hand, the chapter titled “Soil Carbon Sequestration for Climate
Change Mitigation: Some Implications to Egypt” show how in carefully managed
croplands, soil C sequestration can be substantial and represents a potentially constructive portion for mitigating the increased levels of atmospheric CO 2 . The soil is
the largest terrestrial carbon (C) stock, and those factors that affect C retention and
release also influence on atmospheric CO 2 levels. Soil C sequestration represents
about 90% of the total mitigation practices of climate change and about 10% of
emission reduction. There is a great concern of soil carbon (C) sequestration and its
role in absorbing atmospheric CO 2 not only because of its impacts on climate change
mitigation but also because of its positive impacts on the sustainability of crop productivity, soil fertility, and soil quality. Cultivation has resulted in considerable loss