One of the strongest factors that have a negative impact on soil productivity is erosion - the destruction of the upper fertile layer of the soil by natural and manmade forces. The more prone to destruction a land is, the more efforts must be made to preserve its fertility. Unreasonable use of land leads to a rapid depletion of soil, which in the end makes it completely unsuitable for agriculture. In this article, we will consider the types of soil erosion and methods of conservation.
Types of erosion
The surface layer of the soil can be destroyed by the actions of water or wind, so it is customary to distinguish water and wind erosion of the soil.
Wind erosion occurs mainly in steppe areas with large open spaces. It is the weathering of particles of fertile soil in areas not protected by vegetation. Wind erosion is capable of affecting large areas, it is especially dangerous for drained land masses. Most often, territories suffer from wind erosion precisely because of too much economic activities of people.
Water erosion occurs mostly in slopes; in this case, the upper fertile layer of the soil is washed away by rain or water from irrigation canals. As a result, gullies begin to form, and eventually the terrain loses its fertile qualities.
By origin, natural and anthropogenic erosions are distinguished. The first occurs only under influence of natural forces, and does not have a significant influence on fertility of the soil. The second arises from irrational agricultural practices. It is capable of spoiling land in a short time because of the destruction of the fertile layer.
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There are several stages of water erosion:
This is the weakest stage of erosion when soil only begins to be exposed to harmful effects. This phenomenon occurs when drops of rain fall on the ground breaking the cover layer and scattering soil particles. These particles can rise to a height of 0.6 m above the ground, and fly 1.5m away from the site of impact.
In this case, thin layers of the soil are removed by surface currents and rain. The process occurs evenly across the overall area and is often invisible, however, nutrients and valuable substances become lost in the process. A common feature of sheet erosion is the accumulation of plant and soil residues at one end of the field. The most susceptible to this effect are cultivated soils with lack of vegetation to close and protect the land.
Land affected by this kind of erosion is characterized by small, rapidly disappearing, but clearly recognizable drainage lines; these lines are usually no more than 30cm long. Their development occurs if surface water accumulates at low points, destroying soil from inside.
If water is not absorbed into the soil, it flows on the surface and creates small channels called cracks. Problems with rill erosion can be managed with the help of agricultural machinery.
This kind of erosion is the advanced stage of rill erosion. If streams formed on the land are not eliminated, they eventually acquire the scale of large ravines. Such channels have a depth of more than 30 cm and regular cultivation is not enough to remove them.
This phenomenon brings considerable inconvenience to farmers, as damaged land cannot be subject to further processing. Ditches can also be a great danger for people managing machinery.
Methods of soil protection against wind and water erosion
Protecting soil from water and wind can be done by land reclamation and irrigation measures which must be carried out according to a previously agreed plan.
Most of the methods for combating soil erosion are preventive in nature: these measures are not aimed at restoring the soil, but at preventing its erosion. Their timely implementation prevents the appearance of erosion foci and its further distribution.
The range of works on soil protection includes the following main directions:
Organizational and economic work
Periodic survey of fields with the preparation of plans and maps, a comprehensive assessment of erosion processes, the development of an action plan and monitoring of its implementation. Preliminary planning is one of the important factors of success in the fight against erosion.
These measures are a system of crop rotation carried out for the purpose of soil protection. It involves the planting of perennial crops, placement of cultivated plants on the slopes, development and installation of a water retention system to prevent movement of soil. In addition, mineral and organic fertilizers are used. The main task at this stage is to minimize leaching of the ground by water and prevent depletion of the soil.
Forest and hydrogeolioration protection of soil
It involves the planting of forest belts on slopes, an arrangement of channels for the drainage of water, terracing of slopes, creation of dams and artificial reservoirs. These measures help to direct water along chosen routes and protect main land mass.
This is a technique of plowing green mass of plants in soil; it is done during the flowering period. Thus, soil is enriched with useful organic matter, in addition to erosion resistance.
Planting of high-growth crops
Such plants become an effective protective barrier to the wind, significantly reducing its speed and negative impact on the soil. When the sowing of perennial grasses and crops increases, forage lands are automatically improved.
The timely introduction of complex fertilizers in soil promotes the accelerated growth of plants’ root system, which creates an additional powerful barrier to prevent destruction of the soil.
Successful protection of the soil against water erosion also depends on its level of slope; in areas with a small slope not exceeding 2 degrees, surface runoff can be easily minimized. For this purpose, it is sufficient to simply sow cross strips or plants along the contour.
However, in fields located on slopes of up to 6 degrees and above, a wide range of soil protection methods should be used: step-wise plowing, furrowing, dunking and other techniques.
Protective bands can be created from perennial grasses on large fields; this protective grassy strips should be at least 7m. The width of the protective buffer strip should depend on the slope of the field, the higher it is, the wider the bands should be. On steep slopes, it is inadmissible to plant tilled crops.
Putting measures in place to combat water erosion will aid good harvests and ensure the preservation of soil for many years. The condition of land should be assessed periodically so that corrective measures can be applied as needed. Taking good care of the soil will help you achieve good yields for many years.