What’s soil salinization? It’s one of the essential soil problems for agricultural production. Soil salinization refers to the salinity of the level affecting agricultural and environmental health.
Soil salinization usually occurs in arid areas. In these areas, soluble salt ions accumulate in the soil. In these areas where plant growth requires irrigation, the Evaporation and transpiration process leaves salt in the soil.
In the beginning, salts will reduce soil productivity and limit crop yields. When the salinity increases, it will kill the vegetation and soil microorganism. Then the perfectly fertile soil will become completely barren.
How does soil salinization occur? There are many causes of soil salinization. Several factors contribute to an increase in the amount of salt in the soil.
1. Irrigation Water Quality & Volume
The total amount of dissolved salt in irrigated water and its composition affects soil salt content.
The more water you spray, the salinity of the soil will be close to the salt concentration of the irrigation water. When the soil is dry, the concentration of salt in the soil will increase.
Besides, the poor soil drainage leads to low permeability; the salt will accumulate on the soil surface.
2. Fertilizer Composition
Some fertilizers contain high contents of potentially harmful salts, such as potassium chloride or ammonium sulphate. Overuse and abuse of fertilizer lead to increasing salinity in the soil.
3. High Evaporation & Transpiration
In arid areas(High evaporation and transpiration), Plant high water-consuming crops that plants absorb groundwater from the roots through capillary action, leaving salt accumulation.
How Does Salinity Affect Soil
The main effects of soil salinization mainly reflect in impacts of salinity in the soil. Why is soil salinization a severe problem? Because it will cause a series of serious impacts on agricultural production. Including low agricultural productivity, low economic return, and soil erosion.
For Soil
In saline soils, sodium replaces calcium and magnesium, so the aggregation of soil particles is reduced, and the soil will tend to disperse. When soil gets wet, it’s water infiltration capacity reduces as well. When dry, sodic soil becomes hard tends to crack.
For Crops
Salinity affects almost all processes of plants’ growth.
1. Osmotic Stress
It’s the principal cause of reduced plant growth and yield as salinity mounts. Water moves into plant roots by this process, which is controlled by the level of salts in the soil water.
High salt concentration results in high osmotic potential of the soil solution, so the plant has to use more energy to absorb water. Under extreme salinity conditions, plants may be unable to absorb water and will wilt, even when the surrounding soil is saturated.
2. Specific Ion Toxicity
Some ions (particularly chloride) are toxic to plants, and as the concentration of these ions increases, the plant is poisoned and dies.
The immune resistance of the plant becomes low, stunted growth, leaf burn, and necrosis become apparent as the level of salinity increases.
How to Prevent Soil Salinization
Generally, there are four ways to prevent and remediate soil salinization in below:
1. Control irrigation water volume
Apply minimal levels of irrigation water volume and keep the well-drained soil condition.
2. Grow Salt Tolerant Crops
It’s one of the best ways to deal with a soil salinity problem, especially if you are starting. Plant salt-tolerant cash crops such as barley, sunflowers, or canola. Not only are they equipped to deal with the salt, but also drought tolerant.
3. Flush Soil
Flushing the soil is the process of using a low-salt water to irrigate the area and wash the salt below the root zone.
4. Use Bio-Fertilizers
Trichoderma harzianum keeps the soil environment rich in most kinds of nutrients via nitrogen fixation, the release of plant growth regulating substances, and biodegradation of organic matter in the soil. Also, Trichoderma has super adaptability in saline-alkali soil and reproduce rapidly. It’s an extraordinary method to reduce the salt content in the soil. And environment-friendly.
For many soil conditions, multiples solutions of the combination will be the better choice.