Soil Carbon Sequestration for Climate Change Mitigation …
167
different production zones. Those zones are (1) the old irrigated lands (in the Nile
Valley and Delta and most is fertile soils); (2) the newly reclaimed lands (the soil is
poor in OM and macro-and micronutrients), and (3) the rainfed area (sandy soil sited
in the Northwest Coast and North Sinai). However, Abd El Hadi [74] mentioned
that numerous studies had established the poverty of most Egyptian soils in OM
and N content. Additionally; Hegazi et al. [75] reported that extensive and frequent
cropping, under unsustainable irrigation water management and inappropriate agricultural practices, in the Nile Valley and Delta has led to depletion and deficiency in
many nutrient elements. This situation has been aggravated afterward the High Dam
construction, which sharply declined the annual supplements of the fertile sediments
to the soils. Consequently, all Egyptian soils are poor in their content of OM, total
N, and other nutritive elements. As well; FAO [76] confirmed this fact where soils
are poor in OM, with less SOM due to soil warming. Higher air temperatures are
likely to speed the natural decomposition of OM and to increase the rates of other
soil processes that affect fertility. Under drier soil conditions, root growth and OM
decomposition are significantly inhibited, and as soil cover diminishes, vulnerability
to wind erosion becomes higher, especially in case of intensive winds. However, it
is mentioned in IFOAM [77] that with the right type of agriculture, emissions causing climate change can be reduced and nature capacity of the ecosystem to mitigate
climate change can be employed to sequester high quantities of atmospheric carbon
dioxide—especially in the soil. In this context Altieri and Koohafkan [78] reported
that over the world, management practices that used by small farmers such as crop
rotation, composting, green manures and cover crops, agroforestry, in addition to all
practices that increase biomass production, will consequently build active OM.
11.2 Influence of Changing Climate on Soil C and N Stocks
and Sequestration
Thornley and Cannell [79] mentioned that the response of soils to increasing temperature is an important issue. Re-examining the global patterns of soil carbon,
giving a clear trend of decreasing carbon with mean annual temperature for very dry
and very wet biomes. Zhang et al. [80] reported that climatic conditions, especially
temperature and precipitation, may be responsible for the spatial variations in soil
carbon sequestration. Elbasiouny [81] studied the correlation between soil C and N
and temperature in North Nile Delta, Egypt (mean temperature data was obtained
from Central Laboratory for Agricultural Climate (CLAC), Agricultural Research
Center, Egypt). Precipitation is not investigated in this study because its amount in
July (sampling month) is zero in the study area. As presented in Table 1, she found
that the correlation between temperature and soil C and N stocks is negative. The
most affected stock is total soil N stock followed by total soil C stock and SOC
stock equally. The SIC stock was the least affected one. As well the correlation
between temperature and sequestration rate of these stocks is negative, but total soil
167
different production zones. Those zones are (1) the old irrigated lands (in the Nile
Valley and Delta and most is fertile soils); (2) the newly reclaimed lands (the soil is
poor in OM and macro-and micronutrients), and (3) the rainfed area (sandy soil sited
in the Northwest Coast and North Sinai). However, Abd El Hadi [74] mentioned
that numerous studies had established the poverty of most Egyptian soils in OM
and N content. Additionally; Hegazi et al. [75] reported that extensive and frequent
cropping, under unsustainable irrigation water management and inappropriate agricultural practices, in the Nile Valley and Delta has led to depletion and deficiency in
many nutrient elements. This situation has been aggravated afterward the High Dam
construction, which sharply declined the annual supplements of the fertile sediments
to the soils. Consequently, all Egyptian soils are poor in their content of OM, total
N, and other nutritive elements. As well; FAO [76] confirmed this fact where soils
are poor in OM, with less SOM due to soil warming. Higher air temperatures are
likely to speed the natural decomposition of OM and to increase the rates of other
soil processes that affect fertility. Under drier soil conditions, root growth and OM
decomposition are significantly inhibited, and as soil cover diminishes, vulnerability
to wind erosion becomes higher, especially in case of intensive winds. However, it
is mentioned in IFOAM [77] that with the right type of agriculture, emissions causing climate change can be reduced and nature capacity of the ecosystem to mitigate
climate change can be employed to sequester high quantities of atmospheric carbon
dioxide—especially in the soil. In this context Altieri and Koohafkan [78] reported
that over the world, management practices that used by small farmers such as crop
rotation, composting, green manures and cover crops, agroforestry, in addition to all
practices that increase biomass production, will consequently build active OM.
11.2 Influence of Changing Climate on Soil C and N Stocks
and Sequestration
Thornley and Cannell [79] mentioned that the response of soils to increasing temperature is an important issue. Re-examining the global patterns of soil carbon,
giving a clear trend of decreasing carbon with mean annual temperature for very dry
and very wet biomes. Zhang et al. [80] reported that climatic conditions, especially
temperature and precipitation, may be responsible for the spatial variations in soil
carbon sequestration. Elbasiouny [81] studied the correlation between soil C and N
and temperature in North Nile Delta, Egypt (mean temperature data was obtained
from Central Laboratory for Agricultural Climate (CLAC), Agricultural Research
Center, Egypt). Precipitation is not investigated in this study because its amount in
July (sampling month) is zero in the study area. As presented in Table 1, she found
that the correlation between temperature and soil C and N stocks is negative. The
most affected stock is total soil N stock followed by total soil C stock and SOC
stock equally. The SIC stock was the least affected one. As well the correlation
between temperature and sequestration rate of these stocks is negative, but total soil