Soil erosion
- It is of two types: Natural and Accelerated.
- Natural erosion includes Normal process on natural environment, Soil forming and loosing.
- Accelerated erosion includes human influenced erosion considering Detachment, transportation and deposition of soil particles.
Types of Accelerated erosion
- Splash erosion:
- Short movement of soil particles from the origin by rain drop impact force.
- Splash soil particles upto 2ft up in the air
- 5ft horizontally from the source
- On slopping land half of the splash moves down hills
- Destroy soil structure
- Increase soil compactness
- Reduce infiltration and increase runoff
- Then second erosion process ‘transport’ takes place.
- Sheet erosion:
- Even removal of thin layer of soil
- Loss at a point of time: less
- Cumulative loss: significant
- Removes SOM
- Soil color change: dark to light color
- Reduce soil health and changed soil
- faunal and floral (bio) diversity
- Reduce crop productivity
- Add expenditures for farming
- Change soil (Bio-physico-chemical) properties
- Microchannel or rill erosion
- Smooth surface and uniform flow rare in Agriculture
- Irregular land surface caused by tillage and other operations
- Rain water accumulates in depressions
- Accumulated water flows through weak soil surface
- Water flow makes rills in its route
- Rills form as soon as water flows
- Rills fused and become larger and can be crushed by tillage
- Size varies from difficultly visible to easily visible channels
- Particle movement by rill erosion > sheet erosion
- Sheet erosion removes only top soil but rill erosion removes both top and sub-soils.
- Gullying
- Channel erosion that cuts ground deeply and cannot be smoothed easily by ordinary tillage tools
- Runoff increases by volume and velocity and cuts ground deeply developing gullies from rills
- Gullies develop from cracks and tracks developed by tillage and other operations (livestock, machines)
- The rate and extent of gully development is related to amount and velocity of runoff water
The rate and size of gully development also influenced by soil characteristics and slope of the land.
