What is soil? This word has more than one meaning. Most often it occurs in the meaning of "fertile layer". Dictionaries and biological references approach the explanation of the term in more detail.
Soil, according to a scientific definition, is the topmost layer of the earth's lithosphere. Its main characteristics: fertility, heterogeneity, openness, four-phase.
Let's consider each concept separately. Fertility means that soil is a layer suitable for growing agricultural plants and crops. The layer formed as a result of the vital activity of various organisms and weathering is rich in nutrients, and its basis is humus - living organic compounds or their residues that are present in the soil but are absent in living organisms.
What is soil in terms of heterogeneity? This means that the fertile layer is a heterogeneous system, the homogeneous phases of which are separated. So, the soil consists of four phases: solid, liquid, gaseous and microorganisms.
The solid phase includes minerals, organics, various inclusions, i.e. the whole set of solids that make up the fertile layer.
The liquid phase is water, which can be in the fertile layer in a free or bound state.
Gaseous consists of gases: oxygen coming from the atmosphere, complex compounds of nitrogen, methane, pure hydrogen. They are formed as a result of fermentation, respiration, decay, etc.
By exploring the soil, scientists can analyze not only the layer as a whole, but also each of its constituent phases. That is why the complete answer to the question of what soil is is so long. In addition, the soil is sometimes considered as a barrier or membrane, which simultaneously separates and orders the interaction of the atmosphere, bio and hydrospheres.
A slightly different answer to the question of what is soil, GOST 27593-88. It says that the soil is a natural body, independent, organomineral, natural-historical, resulting from a combination of factors:
- man-made;
- abiotic;
- biotic.
Soil, continues the definition of GOST, has its own properties (morphological and genetic). It is characterized by certain properties that are responsible for creating conditions for the development of plants, consists of water, air, mineral particles and organic remains.
The type and nature of the soil depends on the climate, flora and fauna, origin, microorganisms inhabiting the fertile layer. The task of land use is to maintain and maintain fertility, adequately using the capabilities of the layer.
With too frequent use, soils are depleted, with excessive fertilizer they become almost poisonous. In the absence of moisture, the soil can become deserted, and with excessive watering it can turn into ravines. Sometimes soils, as a result of improper use, become salty or marshy. These processes have a single name, namely, soil degradation.
Restoring degraded soils is a very laborious, lengthy, and not always successful process.
