SOIL EROSION
Soil erosion is defined as the detachment, transportation and deposition of soil particle. The soil is transported from one place to another with the help of wind or water and get deposited at a new place, this integrated process is known as soil erosion. Here we will discuss about types of soil erosion and soil conservation.
Why soil conservation is required
Soil conservation is the only known way to protect the soil erosion in a predominantly agricultural country like India where chronic food scarcity is so common due to various famine, flood and drought. Soil conservation works in dual manner it not only increase the crop yield but also prevent the soil from further declination. During this types of soil erosion and soil conservation we must discuss why we need soil conservation.
Types Of Soil Erosion
Broadly soil erosion is classified as -
1- Water Erosion
2- Wind Erosion
Water erosion:-In water erosion the soil is detached and transported with the help of water. Water erosion is further classified into 4 types :-
- Splash Erosion- It is the first stage of water erosion, splash erosion is also known as raindrop erosion. It occurs when raindrop hits bare soil. The explosive impact of breaks the soil aggregate. The splashed particle moves upto 60 cm above the ground and 1.5 m away from the point of impact. The particle block the spaces between the soil aggregate thus reduces infilteration and increases runoff.
- Sheet Erosion- Removal of soil in a thin layer by raindrop impact and shallow surface flow. It results in the removal of finest soil particles that contains most of the available nutrients. Sheet erosion can be identified by several signs such as- bare agricultural land and visible grass roots.
- Rill EROSION- Rills are shallowed drainage line not more than 30 cm( if more than 30 cm it will be gully erosion) . Rill erosion is common in bared in overgrazed area or bared agricultural land, where there is less vegetation. It destroy the soil structure and results into loose soil structure.
- Gully Erosion- As we discussed earlier gully erosion is advanced form of rill erosion. It is the removal of soil by running water with the formation of a channel.Gully erosion cannot be controlled by normal agricultural practices but requires higher level technology.
Water Erosion Control Measure
water erosion control measures are broadly grouped as-Agronomic measure and Mechanical measure.
A. Agronomic measure
1.Contour Cultivation-
Contour cultivation includes contour planning , contour sowing and agricultural operations by ploughing and sowing across the slope. As the ploughing is done across the slope so ridges are formed and each furrow acts as an obstruction to run off or prevent run off. Ultimately it reduces the soil loss. This is common among types of soil erosion and soil conservation.
2- Tillage-
Tillage is mechanical manipulation of land before.... sowing. Tillage alters the physical characterstics of soil i.e., porosity and bulk density. There are different types of tillage implements used seperately in primary and secondary tillage . On the basis of prevention of soil erosion tillage is classified as conventional tillage and conservational tillage. Conventional tillage includes the manipulation of the whole field but in conservational tillage soil is disturb to minimum extent and some crop residue is remained on the field. Conservational tillage reduces 50% more soil loss than the conventional tillage you can study more about tillagebin my previous article about agriculture problem in India https://agritalks031.blogspot.com/2019/07/agriculture-problems-in-India.html?m=1
3 - MULCHING-- -- Mulching is also a great factor which reduces the soil loss and an agronomic measure for soil conservation About 30% ground cover is required to conserve the soil through mulching and to keep the soil loss under control.
4- Strip cropping-- Strip cropping is a system of crop production in which narrow strip of erosion pemitting crop is alternated with erosion resisting crops.
Erosion permitting crop- eg maize and sorghum
Erosion resisting crop- eg. Groundnut and moth bean.
B. Mechanical measure
1- BUNDING-
It is a mechanical method to preven the soil erosion. Land surface is modified in such a way that the water retention increasesin low rainfall area , this type of bunding is called contour bund and dispose the excess water in high rainfall area this type of bundins called graded bunding.
2- Terracing-
Terracing is done in hilly areas to prevent the soil erosion . As farm land of hilly area is very difficult for farming because of uneven surface, so terracing is an ultimate method of farming in hilly areas. Terraces reduces the slope steepness hence obstructs the runoff water, in turn reduces the soil erosion.
These were the measures and their sub divsions which can control the water erosion very effectively . Now we will discuss about wind erosion and their control measure in detail.
WIND EROSION.
In wind erosion wind picks up the lighter soil particles from the surface of the earth and transports them long distance. As wind plays a major role in erosion of the soil so called soil erosion.
Wind erosion control
Wind erosiom control measures aims at reducing wind velocity or altering soil characterstics
Reducing wind velocity
- Wind velocity can be reduced by three methods these measures are vegetative measure, tillage measure and mechanical measure.
These measures are seperately described below in detail:-
1. Vegetative measure-
Shelterbelts play an important role as a vegetative measure in reducing the soil erosion. A series of long trees actsas an obstruction for steepy wind and reduces the velocity of the wind. Large shelter belts are more effective than short ones. Vegetation density should be high and containing about 3 - 10 rows of trees which collectively prevents wind erosion
2.Tillage measure-- A Rough and clody surface resist the force of wind from causing erosion.A stubble mulching helps in reducing the soil erosion.
3. Mechanical measure-- Wind velocity is also reduced by mechanical measures which includes physical obstruction such as terraces, etc. these all physical obstructions which helps in reducing the soil erosion are collectively known as wind breaks.
These were the important measures along with the types of soil erosion and soil conservation which definitely helps the farmers in preventing the soil erosion and develop the good soil structure and in turn results in higher crop yield.
Soil erosion is defined as the wearing away of topsoil. Topsoil is the top layer of soil and is the most fertile because it contains the most organic, nutrient-rich materials. One of the main causes of soil erosion is water erosion, which is the loss of topsoil due to water.
ReplyDeletethanks
Deletelack of importance and knowledge of farming leads people to convert farmland into residential and commercial place.
ReplyDeleteIt causes heavy damage to soil and converts it into soil erosion
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