Kiwa Bio-Tech Products Group Corp (fka KWBT)

[hugh_jackoman]

Impacts of salinization, sodication and waterlogging

http://www.fao.org/soils-portal/soil-management/management-of-some-problem-soils/salt-affected-soils/more-information-on-salt-affected-soils/en/

Salinization, sodication and waterlogging have negative impacts on agricultural production, the living conditions of farmers, the economy at different levels, the balance of ecosystems including the quality of natural resources. The impacts are often felt not only at the farm, but also at lanscape levels. In many countries they can pose serious problems to sustainable development. Examples of effects of salinization, sodication and waterlogging include:

Impacts on crop production

Decline in soil productivity and crop yields
Increased requirement and use of inputs including seeds, water and fertilizers
Low crop yield per unit of input used
Less choice in cropping systems, as farmers are forced to cultivate salt-tolerant crops which might not always be high income cash crops
Reduced water use efficiency
In cases of severe salinization and sodication land cannot be used anymore for production
Impacts on living conditions of farmers and the economy

The reduction of yields results in less income and less food supply, especially in subsistence farming
Working with salt-affected soils requires more labour to reclaim soils
The use of more inputs and the reduction of yields result in less returns
Lowered income and loss of land are often factors for the migration of farmers to cities
Soil reclamation programmes are costly
Rehabilitation programmes to improve the living conditions of those affected require high investments
Impacts on ecosystems

The impacts of salinization, sodication and waterlogging in ecosystems are still not fully understood but they seem to affect both terrestial aquatic ecosystems. From the available research and modelling it is believed that these processes may contribute to:

Reducing the diversity of organisms
Reducing the efficiency of nutrient cycling
Reducing population sizes of previously dominant species
Increasing the populations of salt tolerant organisms
Changing disease patterns and prevalence in different species of plants, terrestrial and aquatic animals
Increasing vector-borne diseases
Salt-affected areas result in sparse vegetation that in turn leads to wind-blown dust storms. Health effects associated with dust may be a problem in salt-affected areas


Impacts on the quality of natural resources

Salt-affected soils are fragil and more prone to other forms of degradation, e.g. wind and water erosion
Wind-born salts can reach and damage vegetation, soils and water in nearby areas
Water draining out of agricultural fields can increase the salt contents in groundwater and other surface water courses
Wastewater from reclamation of salt-affected soils, if not disposed off safely, can contaminate other soils and water bodies
In the case of sodic soils, the loss of organic matter weakens the strength of soil aggregates, increase the loss of nutrients in run-off, and increase carbon dioxide emitted to the atmosphere.
Extreme conditions in sodic soils (pH and sodium salts)decrease water infiltration due to surface sealing and promote runoff during storm events