Keshav Bhatia, Academic Content writer at Edumarz
The Earth’s Crust has a rich load of minerals in it, and these minerals are crucial for the survival of living organisms. Minerals trapped in Rocks are not easily made bioavailable for the living organisms, so the way living organisms get these essential minerals is through Soil.
Soil is made by rock that has been broken down by chemical, biological and physical processes,
This is also known as Weathering.
Different Weathering Processes:
Sunlight and day time heat causes rocks to expand in the daytime and these rocks contract in the night.
As this process of contraction and expansion is not consistent throughout the rock’s body, it ultimately results in cracks which further break down into smaller and smaller components.
Water gets into cracks and as water freezes it expands and widens the cracks
Running water carries sediments and other small rocks which rub against the bigger rocks and weathers them
The reason why soil is found far away from its parent rock is that the flowing water carries these small particles away
Strong winds rub against rocks and erode them
Winds carry sand to far away places
Lichens grow on rocks and release biological products that wear them down and form a thin soil layer.
Mosses like plants grow on this thin layer of soil and lead to further breakdown of the rock
Tree roots sometimes penetrate the existing cracks of rocks and break down the rock further as the roots grow wider and deeper.
Soil is a mixture of fine rock particles, humus (decaying organic material), and microscopic life.
* Average grain size decides the type of Soil
* Nutrient Rich Humus, and microbial diversity and activity decide the quality of the Soil
* Humus increases soil porosity for both air and water
* Mineral constitution of the soil depends heavily on the parent rock
Humus, mineral/nutrient content and Soil depth are some main factors for Soil fertility.
A more fertile soil means that plants will thrive and yield better on that Soil.
The Topsoil consists of Humus, living organisms and Soil particles, biodiversity in that area is decided by the richness of the topsoil.
Modern Farming and Sustainability
Farming nowadays is heavily dependent on fertilizers and pesticides.
Use of these substances over time damages soil structure, harms soil microbial diversity, and kills beneficial organisms(like earthworms) which harms the soil fertility.
Fertile and Rich Soil can turn barren in no time if we do not follow sustainable techniques.
Soil pollution is the destruction of soil organisms, the removal of useful components from the soil, and the addition of harmful ones through indiscriminate and over use of pesticides and fertilizers.
Soil is a priceless resource that takes thousands of years to form.
Sometimes, the factors that have helped the soil form(e.g Wind and water) can be the reason for its erosion.
If all soil gets eroded we as a species will lose this priceless resource and be in grave danger. Almost all agriculture is dependent on soil.
Prevention of Soil Erosion
Plant roots hold soil and keep it from washing away
Deforestation is one of the leading causes of soil erosion and destruction of biodiversity
Nutrient rich and fertile topsoil can be washed away or be removed by wind in no time without vegetation holding it together.
The loss of topsoil is accelerated and heavier in hilly areas.
Soil erosion causes permanent damage to ecosystems and it is very hard to reverse this damage.
Growing vegetation on top soil is one of the most effective ways to prevent soil erosion.