Kenya Soil Water Conservation
Kenya Soil Water Conservation
Soil and water conservation (SWC) efforts should be geared towards equal distribution of water during wet and dry seasons and soil erosion control for enhanced maintenance of soil organic matter and soil physical properties.
Soil threats
source: FAO
Soil erosion
Serious water erosion occurs in regions with dry and wet seasons covering South Asia to East Asia, particularly in the hilly and mountainous landscapes. However, it is of little concern for well-established forests and paddy fields. Wind erosion is concentrated mainly in the most western and northern arid and semi-arid regions of Afghanistan, Pakistan, India, and China. Read more
Organic carbon change
Increase in crop yield retains soil organic carbon (SOC) in croplands of East and Southeast Asia. Whereas, SOC is decreasing in South Asia, because crop residues are widely used as fuel and fodder, and not returned to the soil. The degradation of grassland has caused great losses of SOC stock.
Salinisation and sodification
The threat of salinisation/sodification in the Asia region is widespread but variable. In semiarid and arid zones of central Asia, salt-affected soils are widely distributed. On the other hand, salt- affected soils are developed in certain coastal areas in monsoon zones, mainly by salt water intrusion in South and Southeast Asia.
Nutrient imbalance
Negative soil nutrients balances have been reported for N, P, K and micronutrients in many…” South Asian countries. Whereas, large excess of nutrients, in particular N, causes serious environmental problems in other countries.
Contamination
Rapid urbanization, industrialization, and intensive farming causes contamination of heavy metals (Cd, Ni, As, Pb, Zn, etc.) and pesticides in various parts of Asia, which, in turn, poses a serious risk to human health.
Soil sealing and land take
Rapid urbanization and development of mega-cites significantly increased the rate of impervious surface area (ISA). Asia region has the largest ISA within the global regions.
Soil acidification
There is substantial area of acid soils distributed in tropical and subtropical regions of Asia, mainly in Southeast Asia, parts of East and South Asia. This is mainly caused by unbalanced and unsuitable application of chemical fertilizers. Distribution of acid sulphate soils in tropical Asia also limits crop production.
Compaction
Mechanization of land management has increased compaction of surface soil and/or subsoil in cropland, grassland and timber forests. Increase in livestock trampling is also a major cause of surface soil compaction in grassland and hilly region.
Waterlogging
Anthropogenic activates such as poor drainage system and deforestation in the upstream areas increase the threat to waterlogging in the flood prone areas.
Loss of soil biodiversity
Limited information is available for soil biodiversity in Asia. Some reports show high microbial biodiversity in the soils of organic farming lands.