Give reason for land degradation today.
Answers
Answer:Cutting down of trees
Explanation:People have cut down trees for wood, timber and have also cut them down for land for building houses due to increase in population.
Answer:
1. Deforestation:
Forests play an important role in maintaining fertility of soil by shedding their leaves which contain many nutrients. Forests are also helpful in binding up of soil particles with the help of roots of vegetation. Therefore, cutting о forests will affect the soil adversely.
2. Excessive Use of Fertilizers and Pesticides:
Fertilizers are indispensable for increasing food production but their excessive use has occasioned much concern as a possible environmental threat. Excessive use of fertilizers is causing an imbalance in the quantity of certain nutrients in the soil. This imbalance adversely affects the vegetation.
3. Overgrazing:
Increase in livestock population results in overexploitation of pastures. Due to this, grass and other types of vegetation are unable to survive and grow in the area, and lack of vegetation cover leads to soil erosion. Millions of people in Africa and Asia raise animals on pastures and rangelands that have low carrying capacity because of poor quality or unreliable rainfall Pastoralists and their rangelands are threatened by overgrazing.
Pastoral associations in West Africa have tried with mixed success to improve the productivity of common held livestock pastures. The Aga Khan Rural Support Programme has been successful in improving management of common grazing lands.
4. Salination:
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Increase in the concentration of soluble salts in the soil is called salination. India has about six million hectares of saline land.
The origin of saline soil depends on the following factors:
1. Quality of Irrigation Water:
The ground water of arid regions are generally saline in nature. The irrigation water may be itself rich in soluble water and add to salinity of soils.
2. Excess Use of Fertilizers:
Excess use of alkaline fertilizers like sodium nitrate, basic slag, etc. may develop alkalinity in soils.
3. Capillary Action:
Salts from the lower layers move up by capillary action during summer season and are deposited on the surface of the soil.
4. Poor Drainage of Soil:
Salts dissolved In Irrigation water accumulate on the soil surface due to inadequate drainage, especially during flood.
5. Salts Blown by Wind:
In arid region near the sea, lot of salt is blown by wind and gets deposited on the lands.
5. Water-logging:
Excessive irrigation and improper drainage facility in the fields cause rise in the ground water level. This ground water mixes with surface water used for irrigation and creates a situation called water-logging. Ground water brings the salts of soil in dissolved state up to the surface where they form a layer or sheet of salt after evaporation. The term salinity is used for such a situation.
6. Desertification:
Desertification is a widespread process of land degradation in arid, semi- arid, and dry sub-humid areas resulting from various factors, including climatic variations and human activities. The UNO Conference on Desertification (1977) has defined desertification as the “diminution or destruction of the biological potential of land, and can lead ultimately to desert like conditions.”
Explanation: