Problems of Soil increaing day by day whereas Soil plays a central role for economic and social development. It ensures food, fodder and renewable energy supplies to sustain human, animal and plant life.
According to New Delhi-based National Academy of Agricultural Sciences (NAAS), the annual soil loss rate in our country is about 15.35 tonnes per ha, resulting in loss of 5.37 to 8.4 million tonnes of nutrients.
Causes of soil degradation
- Soil erosion
- Decline of soil fertility
- Water logging
- Shifting cultivation
- Water is considered the main cause of soil erosion among the agents.
- Main agents of soil erosion are (1) Water, (2) Wind, (3) Waves and (4) Glaciers
- The removal of the top layer of soil, known as soil erosion, occurs through various means, including natural events and human activities.
- Water-caused soil erosion can be classified as below:
- Sheet Erosion: Uniform removal of the top soil just like a sheet.
- Rill Erosion: Heavy water flow cause rill in Land.
- Gully Erosion: Rill will enlarge as Gullies and land will be disordered. ( eg: Chambal Valley)
CONSEQUENCES OF SOIL EROSION
- Fertility of top soil will be lost.
- Erosion washes away nutrients, leading to a decline in their content.
- The reduction of underground water level will occur.
- Loss of vegetation and habitat.
- Drought and flood become frequent.
- Rivers get dried off.
Decline of soil fertility
- The states of Punjab, Haryana, and U.P. mostly experience the impact of soil fertility.
- Even with adequate irrigation and nutrient supply, the soil is not producing enough.
- The major reasons for decline of soil fertility are:
- Frequent cropping
- Unscientific rotation of crops
- Extensive and excessive use of chemical fertilizers
- Too much use of chemical pesticides
- Land should left uncultivated for a period of time and let to retain its fertility. Cropping after cropping will leave the land unfertile.
- Leguminous plants can be cultivated in intervals which will increase the fertility of the soil.
- If there is no proper drainage system in the land, the land will become waterlogged.
- This results in the saturation of crops.
- Construction of proper drainage system to allow water flow away from the land is the best way to reduce water logging.
- The normal circulation of air will not be possible due to water logging and the amount of oxygen in the soil will decline.
- Soil will become saline or alkaline in low rainfall areas. Rajasthan is an example.
- When the sea water enters the land, the soil becomes saline.
- The presence of calcium carbonate beneath the soil (kankar) causes water to get logged, as observed in the Indira Gandhi canal regions of Rajasthan. If the soil contains salt content, it will spread to the whole land due to this.
Shifting / Jhum cultivation
- Shifting cultivation is a type of cultivation practiced mainly in North-Eastern states of India
- It is a type of slash and burn method of cultivation.
- After reaping the crops, people slash and burn the land, typically the forest.The next cultivation will be in another plot and the burned land will let uncultivated for a period.
- In the early periods, the gap between two cultivations in a land was 10-20 years.
- The gap decreased to merely 2-3 years due to population increase and reduced land availability.
- This causes major deforestation, environmental pollution, loss of habitat for wild animals etc.
- The burning of forest results in soil erosion and gradual degradation of soil.
Problems of Soil,Problems of Soil,Problems of Soil
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