Soil retrogression and degradation

**Soil Retrogression and Degradation Overview:**
– Soil retrogression and degradation are regressive evolution processes.
– Retrogression is primarily due to soil erosion, while degradation is linked to local climate and vegetation.
– Globally, 33% of pastureland, 25% of arable land, and 23% of forests have deteriorated, impacting 3.2 billion people.

**Ecological Factors Influencing Soil Formation:**
– Climate, vegetation biome, original rock, and drainage influence soil evolution.
– Alteration, humification, and local factors play significant roles in soil development.
– Different climates lead to diverse soil formation processes, affecting specialized associations like peat bogs.

**Human Activity and Soil Degradation:**
– Soil erosion, accelerated by human activities like improper agriculture practices, is a primary factor in soil degradation.
– Overgrazing, monoculture planting, tilling, and land-use conversion impact soil health.
– Destruction of vegetation, leading to erosion and retrogression, can be caused by human actions.

**Consequences of Soil Regression and Degradation:**
– Soil degradation reduces food production capacity, affecting over 6 billion people using 38% of Earth’s land for agriculture.
– Yield reductions of 10% to over 50% are seen in degraded soils, with severe cases mostly in developing countries.
– Natural disasters like mud flows and floods are linked to soil degradation consequences.

**Economic and Environmental Impacts:**
– Land degradation costs US$44 billion annually, with global soil loss amounting to US$400 billion per year.
– Severe economic impacts are seen in regions like South Asia and sub-Saharan Africa due to land degradation.
– Soil enhancement and regeneration practices, such as improving structure and adding organic matter, can combat soil erosion and degradation.