explain the main cause of land degradation
Answers
Answer:
Land degradation is a main issue globally right now.
It happens due to :-
1). Deforestation - as urbanisation increases forests are going down. Trees and plants plays vital role in maintaining soil fertility.
2). Overgrazing - cattles and animals fed on shrubs are overgrazed which reduces the plants and results into land degradation.
3). Soil Erosion - soil erosion is mainly seen in those areas where there are less trees and less plants. Due to soil erosion the humus content of the soil reduces due to which the organic material present in the humus also runs off.
4). Fertilisers - synthetic chemical Fertilisers used increase the inorganic content in the soil. Which harms the microorganisms present in thw soil making the soil infertile.
Answer:
the main causes for land degradation are as follows:
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.
The word pesticides includes any form of chemical used for the control of unwanted herbaceous plants (herbicides), woody plants (arboncides), insects (insecticides) or any chemical that has biocidal activity affecting rodents, arachnids or any other population. After Second World War the use of pesticides increased tremendously.
Although their success in controlling pests on a short-term basis cannot be denied, but their long-term effectiveness in controlling pests or their overall effects on ecosystems (including human health) and environment has to be seriously questioned on two major grounds.
These are:
(a) Increasing concentration of pesticides residues as they move up the food chain; and
(b) Rapid evolution of new breeds of pests that are immune to the pesticides applied.
Moreover, excessive use of these pesticides, results in an increase in the level of resistance by certain pests and it may kill some useful species like earthworm which are very helpful in maintaining soil fertility. Thus, the use of pesticides leads to decline in the fertility status of soil.
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:
Increase in the concentration of soluble salts in the soil is called salination. India has about six million hectares of saline land.
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