Mineral riches in the soil:
- The biosphere supports life on the earth.
- It consists of three sub-zones, namely lithosphere (rock, outermost layer), hydrosphere (water) and atmosphere (air).
- The soil forms the lithosphere or the crust or the outermost layer, of the earth.
- This layer is rich in minerals required by living organisms.
- Soil is a mixture of minerals and other matters, similar to the mixture of gases in air.
- This topmost layer is called topsoil, depending on which, the biodiversity of a region also varies.
- Soil is composed of dead and decayed matter, microorganisms and other minerals which are useful for living organisms, called humus which is a crucial factor that decides the fertility, texture and other characteristics of the soil.
- The soil is divided into different types based on the soil particle size, humus content and microorganisms present.
- The richness of minerals in a type of soil depends on the parent rock it was formed from.
- Water and the wind take away the minerals and other contents of the soil.
- Soil is vital for plants to survive.
- The minerals and nutrients present, humus content, consistency, etc. are some important factors to be considered for cultivation.
- The top layer of soil contains minerals, humus, microorganisms and other particles.
Soil Erosion is the removal and transportation of the top layer of soil from its original position to another place, under the effect of strong winds and fast running rainwater.
Causes of Soil Erosion
Soil erosion is caused by: Strong winds, heavy rains, improper farming and suspended cultivation, human actions, dust storms, frequent floods, deforestation, overgrazing, urbanization, industrialization.
Effects of Soil Erosion
The following are the effects of soil erosion:
- Loss of fertility and desertification.
- Landslides in hilly areas
- Flash floods
- Silting of water reservoirs
Prevention of Soil Erosion:
Reforestation and afforestation help to prevent soil erosions and loss of other valuable resources. Other methods include:
- Intensive cropping
- Sowing grasses and planting xerophytes.
- Terrace farming (terracing)
- Contour bunding
- Conservation tillage
- Wind breaks.
- Proper drainage canals around the fields.
- Making strong embankments along the river banks.
Soil degradation due to extensive farming:
Large amounts of fertilizers and pesticides are used in modern farming practices. This has bad impacts on the soil. The impacts are:
- Destroys soil structure: Fertilizers and pesticides destroy the soil structure by killing humus that recycle nutrients in the soil.
- Kills earthworm: It also kills the earthworms which are helpful in making the rich humus.
- Fertile soils become barren: In case oh not following sustainable practices, like removal of useful components (nutrients) from the soil and addition of other substances (fertilizers, pesticides etc.) affects the fertility of soil. Thereby killing of diversity of organisms that live in it. This causes soil pollution.
Causes of soil pollution:
Soil pollution is caused by
- Solid wastes and chemicals.
- The slag heaps from mines spoil the beauty of sites of mines pulp and paper mills, sugar mills, oil refineries, power plants, chemicals and fertilizer manufacturing units, iron and steel plants, plastic and rubber producing complexes are some major contribution to soil erosion.
- Most industrial furnaces and thermal power stations produce fly ash, which is powdery residue of unburnt material, and causes pollution.