Soil degradation and desertification Ashish(2011A22BIV)

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  • 1. SOIL DEGRADATION AND DESERTIFICATION-A Challenge By:ASHISH(2011A22BIV)
  • 2. SOIL DEGRADATION • Soil degradation is the decline in soil quality caused by its improper use, usually for agricultural, pastural, industrial or urban purposes. • The Decline in quantity and quality of soil It includes Erosion by wind and water Biological degradation (loss of humus) Physical degradation (loss of structure, permeability, compaction) Chemical degradation (reduced fertility, salinisation , changing pH, toxicity)
  • 3. SOIL DEGRADATION DESERTIFICATION If Degradation is so severe that land becomes unusable it is termed desertification
  • 4. DESERTIFICATION • Desertification is a process of turning the productive land into desert. • A definition of desertification should recognize that it is a land degradation process that involves a continuum of change, from slight to very severe degradation of the plant and soil resource, and is due to man's activities. • Desertification is also a situation on the desert expansion. That means desert is continuously expanding to the surrounding area.
  • 5. Causes on desertification desertification Climatic change Human factors High pop. + Poor / poverty Impropriate irrigation -salinization Over grazing deforest ation Global warming Over cropping ↓ Soil fertility ,↓ soil degradation &↓ Soil aridity Low Rainfall
  • 6. Cause Human factors: High population Deforestation---∵Demand more land and timber for cropping & building, cutting down to tree extensively. Over cropping—-∵demand for food crops↑ & the cash crops demanded ↑, ↑shifting cultivation, ↓soil fertility, secondary growth
  • 7. Cause Impropriate irrigation: infiltration >E underground water table rises salinization Climatic change Global warmingCO2↑, T ↑, ice cap melt, flooding in coastal area , ↓ rainfall, drought , veg. die Less rainfallDrought , veg. die.
  • 8. “If the climatic factors are said to be the main causes of desertification ,then human activities are going to intensify it.”
  • 9. Effects on desertification desertification Atmosphere Hydrosphere Lithosphere Biosphere -local climate -water cycle -loss of arable breaks down salinization -extinction of plants & animals ↓R” drought -macro climate -land intensify the soil erosion global warming Upset the balance of ecosystem -↓biodiversity
  • 10. Effects
  • 11. Effects Lithosphere 1)loss of arable land soil texture change to sandy  ↓cohesive power (cannot hold water) not suitable for veg growth 2)intensify the soil erosion 1.↑ deforestationno root to bind the soil  ↑ soil erosion↑ silting
  • 12. Effects Hydrosphere 1)Water cycle breaks down ∵↓Rainfall & ↑ evaporation(∵ no shelter)  rivers and wells dried up Biosphere 1)lower the bio-diversity ↓R” & unevenly dis.+deforestation scattered veg. (veg. Is shorter, few species, less luxuriant)extinction
  • 13. Effects Others 1)lower the income Rainfall ↓ crops productivity ↓, 2)use a large amt of capital for soil protection & recovery
  • 14. How to solve??? 1.Control the pop. growth / natural increase by using family planning, in order to decrease the land use capacity 2.The number of grazing and the rate of cultivation should not over the carrying capacity of land
  • 15. How to solve??? 3. Improve i)farming & ii)grazing methods, in other to reduce soil erosion and salinization i) suitable timing and amount to carry out irrigation plant the halophytes (which can adapt salty & droughted soil) e.g, Chenopodiaceae ii)sufficient fallowing period
  • 16. How to solve??? 4.Legislation: band the deforestation and over grazing, etc. , in order to balance the ecosystem of desert. 5.afforestation i.e. plant the wind break trees & drought resistant plants 6.stone lines 7. Building reservoir and canal , (e.g, The Indira Gandhi Canal)