Soils as Driver and Victim of Climate Change in Egypt
131
Fig. 11 Impact of the
depletion of soil organic
matter resulted from global
warming on soil properties
4.1.1 Decline of Soil Fertility
Organic matter plays a key role in maintaining soil fertility. It holds nitrogen and
sulfur in organic forms and other essential nutrients such as potassium and calcium.
The decline in SOM due to global warming may induce disturbance in soil fertility
balance. The causes of the decline in soil fertility could be:
• The decrease in organic matter content and soil bioactivity: The decreased levels
of organic matter causes a strong reduction in soil fertility as it plays several
roles in the soil. Decreased organic matter levels result in poor physical, chemical,
and biological properties. The microbial activities in soil decrease due to reduced
levels of organic matter. These microbial activities play a significant role in nutrient
availability and recycling
• Nutrient mining
• Loss of nutrients through various routes, (leaching, volatilization, runoff)
• Soil acidification, salinization, and alkalinization
• Soil pollution.
Warmer soil temperature will accelerate soil processes, rapid decomposition of
organic matter, increased microbiological activity, quicker nutrients release, increase
nitrification rate and generally accentuate chemical weathering of minerals. However, soil temperatures will also be affected by the type of vegetation occurring at its
surface, which may change itself as a result of climate change or adaptation management [112]. “Organic matter is particularly important as the prime habitat for
immense numbers and variety of soil fauna and microflora, which play a critical role
in the nutrient storage and turnover, health, and productivity of soils” [113].
131
Fig. 11 Impact of the
depletion of soil organic
matter resulted from global
warming on soil properties
4.1.1 Decline of Soil Fertility
Organic matter plays a key role in maintaining soil fertility. It holds nitrogen and
sulfur in organic forms and other essential nutrients such as potassium and calcium.
The decline in SOM due to global warming may induce disturbance in soil fertility
balance. The causes of the decline in soil fertility could be:
• The decrease in organic matter content and soil bioactivity: The decreased levels
of organic matter causes a strong reduction in soil fertility as it plays several
roles in the soil. Decreased organic matter levels result in poor physical, chemical,
and biological properties. The microbial activities in soil decrease due to reduced
levels of organic matter. These microbial activities play a significant role in nutrient
availability and recycling
• Nutrient mining
• Loss of nutrients through various routes, (leaching, volatilization, runoff)
• Soil acidification, salinization, and alkalinization
• Soil pollution.
Warmer soil temperature will accelerate soil processes, rapid decomposition of
organic matter, increased microbiological activity, quicker nutrients release, increase
nitrification rate and generally accentuate chemical weathering of minerals. However, soil temperatures will also be affected by the type of vegetation occurring at its
surface, which may change itself as a result of climate change or adaptation management [112]. “Organic matter is particularly important as the prime habitat for
immense numbers and variety of soil fauna and microflora, which play a critical role
in the nutrient storage and turnover, health, and productivity of soils” [113].