How does soil irrigation increase salinity

Known countermeasures

Countermeasures are already in place against some types of soil degradation, and they are used regularly and on a large scale. I would like to introduce some of these methods here.

Salinization of the soil

Two methods are regularly used to combat soil salinization. But there are other methods to bring life back to an over-salted soil.

These methods are regularly used, even on a large scale, and have been tried and tested:

  • The removal and disposal of the top soil layer until uncontaminated soil is exposed again. Then you can plant new vegetation and the soil will recover in a few months.
  • The most commonly practiced method, however, is washing out the salt. The salt is rinsed out with large amounts of water and drained off before the liquid can evaporate on the surface. However, this process must be carried out several times in order to achieve the desired result.

Furthermore, you can use the saline soil for other purposes:

  • There are plants that grow even in salty soil or in salt water. These plants are called halophytes or simply salt plants. There are plants that can only grow on salty soil (obligate halophytes), and plants that can grow on both salty and normal soil (optional halophytes).
    • The halophytes include the mangroves. For example, you can plant a mangrove forest.
    • The cultivation of optional halophytes would be particularly useful. Because these will continue to grow if or if the salinity of the soil normalizes again.
  • A countermeasure that has not yet been confirmed and which still needs to be tested extensively is the soaking up of the salt with Oscher (Calotropis procera). This is where the Oscher supposedly stores the salt. When you then harvest the plants, you also remove the salt from the property.

Soil acidification

To counteract soil acidification, the pH value of the soil must be raised to a healthy level again. But you have to be careful not to go too fast. If the pH rises too quickly, the microorganisms in the subsurface will be shocked and you will do more damage than you have repaired.

The pH value can be increased by liming with limestone powder or quicklime. This is simply sprinkled on the ground.

Vegetable ash is also often distributed in forests. In addition to the substances that adjust the pH value, it also contains a number of useful nutrients.

Water erosion

Sloping plains are very vulnerable to water erosion. Because when water runs down a slope it develops enormous forces and pulls everything with it that gets in its way.

That is why such sloping surfaces are often treated with terracing. If the water doesn't run down the slope as quickly, it can't do as much damage.

Trees are also often planted on steep slopes in order to "hold" the ground with their roots and thus prevent it from being washed away by the water.

Another advantage of terracing, in addition to reducing water erosion, is the storage of water. If small water reservoirs are built in at the edges of the terraces, water can be retained for the vegetation in regions with little rain and prevented from draining.

Wind erosion

To combat wind erosion, the only thing that helps is to protect the ground from wind. If it is not possible to protect it with vegetation, you have to build windbreaks or hedges.

Desertification

Desertification presents a particularly great challenge that mankind has faced in vain for centuries. Nevertheless, there have been some promising ideas, projects and experiments for several years that are already having an effect. I would like to list two of them here:

  • Manual afforestation of desertified land. There are several projects that are working on planting large forests to combat desertification with biomass and forests. These forests offer protection from wind and help the soil better absorb precipitation. Examples of such projects are:
    • China's Green Wall. A project by the Chinese government to stop the desertification in China.
    • The green wall of Africa. Here a belt of trees is being planted across Africa in the Sahel zone in order to limit the progressive desertification.
  • Hollistic Livestock Management. Here the reasons for the progressive desertification are felt on the tooth, and nature is imitated in order to stop them. It was found that steppe landscapes that were not periodically trampled down and grazed by migrating herds of large animals slowly deteriorated further and further. The usual animal husbandry with large pastures and a small number of animals that grazed permanently on the same area accelerate this effect. It has been found that steppe plants require periodic clear erosion and fertilizer from large numbers of animals. So Hollistic Livestock Management was developed - here, large numbers of livestock are led in periodic cycles over several pastures in order to imitate the migrating herds. [1] [2]
  • Enhancement through nano clay in connection with planting vegetation for stabilization. Tiny clay particles, so-called nanoclay, are mixed with water and distributed over the sand. The nanoclay then settles in the upper layer of the desert floor, in the first 10-15 cm, around the grains of sand. This creates fertile soil. In the resulting soil layer, water can now be stored and microorganisms can settle. In order to fix this condition and to prevent the new, fertile soil from being lost again, vegetation is still required. This can now be planted. The vegetation that has now been planted can thrive in the newly created soil and now further enhances it.

Chemical degradation

Countermeasures against chemical degradation are similar to those of soil salinization. There are options to completely remove the soil, which is extremely expensive and very costly, and the option to clean the soil through vegetation - this is called phytoremediation.

Phytoremediation is based on the fact that different plants break down different (harmful) substances, absorb them and also release them into the environment. For example, there are plants that absorb heavy metals from the soil. These heavy metals are then simply harvested when the plants are harvested. There are also plants that can simply neutralize various toxins in the soil or release them from the soil into the air. In general, there is a certain plant for an extremely large number of different chemical loads in the soil that can eliminate or at least mitigate the loads.