After reading this essay you will learn about:- 1. Meaning of Waterlogging 2. Causes of Waterlogging 3. Effects 4. Remedial Measures.
Essay on the Meaning of Waterlogging:
A land is said to be waterlogged when the soil pores within the root zone of the plants get saturated, and the normal growth of the plant is adversely affected due to insufficient air circulation. The waterlogged land results in reduction of agricultural production.
The problem of waterlogging is a world-wide phenomenon which occurs mainly due to the rise of ground water table beyond permissible limits. The problem of waterlogging has already affected about 6 million hectares of culturable land in India.
Essay on the Causes of Waterlogging:
The main causes of waterlogging can be grouped into two categories:
(i) Natural, and
Topography, geological features and rainfall characteristics of an area can be the natural causes of waterlogging. Introduction of surface water irrigation facilities disturbs the balance between natural outflow and inflow of a ground water reservoir.
This forms the artificial cause of waterlogging. Besides, defective methods of cultivation, defective irrigation practices and blocking of natural drainages are also included in the artificial causes of waterlogging.
Essay on the Effects of Waterlogging:
Following are the adverse effects of waterlogging:
(i) Absence of soil aeration
(ii) Difficulty in cultivation operations
(iii) Weed growth
(iv) Accumulation of salts.
In addition, the increased dampness of the waterlogged area adversely affects the health of the persons living in that area.
(i) Absence of Soil Aeration:
In waterlogged lands, the soil pores within the root zone of crops are saturated and air circulation is cutoff. Waterlogging, therefore, prevents free circulation of air in the root zone. Thus, waterlogging adversely affects the chemical processes and the bacterial activities which are essential for the proper growth of a plant. As a result, the yield of the crop is reduced considerably.
(ii) Difficulty in Cultivation:
For optimum results in crop production, the land has to be prepared. The preparation of land (i.e., carrying out operations such as tillage, etc.) in wet condition is difficult and expensive. As a result, cultivation may be delayed and the crop yield adversely affected. The delayed arrival of the crop in the market brings less returns to the farmer.
(iii) Weed Growth:
There are certain types of plants and grasses which grow rapidly in marshy lands. In waterlogged lands, these plants compete with the desired useful crop. Thus, the yield of the desired useful crop is adversely affected.
(iv) Accumulation of Salts:
As a result of high water table in waterlogged areas, there is an upward capillary flow of water to the land surface where water gets evaporated. The upward moving water brings with it soluble salts from salty soil layers well below the surface.
These soluble salts carried by the upward moving water are left behind in the root zone when this water evaporates. The accumulation of these salts in the root zone of the soil may affect the crop yield considerably.
Essay on Remedial Measures of Waterlogging:
The main cause of waterlogging in an area is the introduction of canal irrigation in the area. It is, therefore, better to plan an irrigation scheme in such a way that the land is prevented from getting waterlogged.
Measures, such as:
(i) Limiting the intensity of irrigation,
(ii) Provision of intercepting drains,
(iii) Keeping the full supply level of channels as low as possible,
(iv) Encouraging economical use of water,
(v) Removing obstructions in natural drainage,
(vi) Rotation of crops,
(vii) Running of canals by rotation, etc.
Can help considerably in preventing the area from getting waterlogged.
Combined use of surface and subsurface water resources of a given area in a judicious manner is called conjunctive use of water. During dry periods, the use of ground water is increased which results in lowering of the water table. The use of surface water is increased during wet season. Because of the lowered water table, ground water reservoir receives rainfall supplies through increased percolation.
Utilisation of water resources in this manner results neither in excessive lowering of the water table nor in its excessive rising. Conjunctive use of surface and subsurface water serves as a precautionary measure against waterlogging. It helps in greater water conservation and lesser evapotranspiration losses, and brings larger area under irrigation.