What is salinization of soil?
The type of soil that has a higher concentration of water-soluble salt is named saline soil and the process by which salt is accumulated in the soil is called salinization of soil. The water-soluble salt could be sulfate of sodium, potassium, calcium, and magnesium. Despite this, chloride, carbonate and bicarbonate of alkaline elements are also water-soluble salts that can increase soil salinity.
Salinization of soil is mostly seen in dry areas where rainfall is a low factor. Because in the arid areas water gets evaporated and the salt remains in the topmost layer of soil. But in rainy areas, salt dissolves in water and leaches into the ground. This is a natural process of soil salinization. However, human activities are another cause of soil salinization.
Sign of soil salinity
How is the saline soil identified, and how can the concentration of salt in such land be determined. When the soil has low salts, the initial signs include:
- Such lands have a lot of moisture, which means that they look mostly wet.
- The growth of some unwanted weeds can be seen among the crops.
If the amount of salt in the land is high then some such signs can be seen:
- The top layer of the ground turns white
- For plants, it becomes difficult to absorb water from the soil. Therefore, irregular growth of crops was observed in such lands.
- Some salt-tolerant plant growth can be observed.
Soil salinity meter
Salinity meter is the device that measures the salt level by checking the conductivity of the soil. Some meter measures the salt values, ph level, and temperature of the solvent too. Such devices have a probe that conducts the electric current and according to meter’s algorithm, they show results on display.
Cause of soil salinization
- Some farming activities cause soil salinity such as plowing at the same depth again and again.
- Some long-term factors including groundwater hydrology, long-term climate, and topography affect soil salinity.
- High underground water level reduces the ability of plants to absorb water The presence of a hard layer (rock) in the soil profile reduces the leaching process.
- Lack of drainage
- The soil salinity increases due to some short term factors including land use, farming practice, evaporation.
Effects of soil salinization
Due to the excessive amount of salt in the soil, the roots of the plant couldn’t absorb the water from the soil. Because the salt concentration in soil is more than that of salt concentration in the roots of the plant. But on the contrary, water comes out from the root cells. So, saline soil reduces the productivity of crops. And this is one of the reasons for soil degradation.
Due to the salt scattered on the soil, the leaching properties of the land are reduced. Therefore, mud can be seen on such land.
The soil salinity also reduces the quality of surface water such as sloughs, shallow groundwater and ponds, and dugouts. Evaporation can concentrate salt in the water at such a level that it’s dangerous for animals and especially freshwater fish.
How to control soil salinity?
- Removes the salts above the surface by creeping.
- Fill the field with water to ensure leaching is good
- Depth tillage is important for the leaching process and some conservation tillage may be used
- Some farming practices such as growing salt-tolerant crops, reducing summer mates, reducing crop rot control the soil salinity.
- Some chemical methods can be applied such as chemical fertilizers which can neutralize the salt. Gypsum is one of those chemicals.
- Organic materials are good for such land to neutralize the salt
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