What Does Waterlogging Mean?
Waterlogging occurs when the soil in a particular region is completely saturated with water.
Waterlogging can have several causes, including:
- Excessive rainfall
- Poor drainage
Waterlogging can cause soil displacement, restrict their air supply that normally flows through the pores of the soil, and impede the growth of vegetation. The restriction of airflow in the soil can cause its oxygen levels to decline and its levels of carbon dioxide and ethylene to increase.
Safeopedia Explains Waterlogging
Soils that drain poorly or heavy soils that are compacted can become waterlogged more easily. When soil reaches this oversaturated condition, the soil becomes an anaerobic atmosphere that can adversely affect the crops that grow in it.
Types of Waterlogging
There are different types of waterlogging that happen due to different conditions in an area.
- Riverine Flood Waterlogging: Occurs when heavy rain floods rivers, causing water to seep into nearby land.
- Oceanic Flood Waterlogging: Caused by extreme weather conditions like hurricanes and tsunamis bringing ocean water to the land.
- Seasonal Waterlogging: Runoff water from rain can accumulate in lowlands and depressions leading to waterlogging.
- Perennial Waterlogging: Occurs when rainwater enters swamps and other wetland areas, causing run-off that seeps into the surrounding soil.
- Sub-soil Waterlogging: During heavy rainfall, the water table can sometimes rise high enough to reach the pores in the region of the crop roots. Repeated incorrect irrigation can cause the formation of a shallow impermeable layer that prevents water from infiltrating down.
Signs of Waterlogged Soil
Waterlogging often goes unnoticed until the water starts collecting at the surface of the soil. By this point, however, the roots of the plants may have already been damaged.
Knowing the signs of waterlogged soil can help identify the issue before it's too late. Many of the early symptoms are similar to those of water stress, where plants receive too little water. They include:
- Yellowing leaves or decay between veins resulting in soft spots at the base or leaf center
- Blue-black roots
- Peeling bark
- A sour, rotting smell
- Roots that appear pruned from the tip due to decomposition
- Dying shoots
- Stunted plant growth
Effects of Waterlogging
When water displaces the oxygen in soil, it can slow or stop the growth of plants. Excess water also changes the pH level, making it more acidic. It also affects the level of nitrogen present in the soil.
Waterlogging also cools the soil temperature, which prevents microorganisms from performing activities that are essential for plant growth. It can, moreover, encourage the growth of weeds that thrive in wet conditions.
Finally, waterlogged soil is an ideal breeding ground for mosquitos, slugs, and other pests.