Text 3 Soil Classification
3.1 Read the following international words and translate them: classification, production, taxonomy, facts, systems, scheme, reason, characteristics, groups, erosion, profile, horizon, chemical, basis, deficiency.
3.2 Say it in Russian: Russian scientist, soil’s morphology, Canadian system, soil profile characteristics, other similar areas, flooding, wind erosion, soil horizons, texture and structure.
3.3 Read the following pairs of words and translate them:
Europe - European, US - American, Canada - Canadian, France - French, Russia – Russian.
3.4 Read and translate the text with the help of a dictionary.
The modern classification of soils began with the Russian scientist Docuchaev in the 1880s. Soil surveys in the US, Europe and Canada began only a few years later. How do we classify soils? We could probably develop many classifications based upon how soils
were formed by the environment.
could be used for crop production
could be used for building.
Today we use a scientific taxonomy based upon the soil’s morphology (or its shape and form). From this classification we can interpret important facts relating to crop production, management and so on. However, there are many classification systems used throughout the world. Canada has its own, as does the U.S.A. Fortunately, it is relatively easy to translate from one scheme to the other. The Canadian system (and most others) arranges soils into groups based upon the soil profile characteristics.
Why Classify Soil? Classification allows us to communicate our ideas and research about soil and extrapolate them to other similar areas. It also allows us to predict the behavior of soils such as which soils are most subject to flooding or wind erosion? Or which soils will be most likely to have a sulfur deficiency?
Soil Profile It is important to think of soils in three dimensions; i.e. the soil has depth. Understanding the soil profile is essential to be able to classify soils. The formation of the layers or soil horizons is a result of the environmental forces that have acted upon the soil during its formation, often of thousands of years. The colour, texture and structure of each horizon and often its chemical characteristics are used to group soils and form the basis of most systems of soil classification.
The result of all of these forces is soil that develops into layers known as horizons. The first or top 48 inches of these horizons and its' unique set of characteristic is used by soil scientist to classify and name a soil. Just as an oak tree is named due to its' unique characteristics, so is a soil. These horizons collectively are known as a soil profile. The thickness varies with location, and under disturbed conditions: heavy agriculture, building sites or severe erosion for example, not all horizons will be present.
T
he
uppermost is called the organic horizon or O horizon. It consists of
detritus, leaf litter and other organic material lying on the surface
of the soil. This layer is dark because of the decomposition that is
occurring. This layer is not present in cultivated fields.
Below is the A horizon or topsoil. Usually it is darker than lower layers, loose and crumbly with varying amounts of organic matter. In cultivated fields the plowed layer is topsoil. This is generally the most productive layer of the soil. This is the layer that soil conservation efforts are focused.
As water moves down through the topsoil, many soluble minerals and nutrients dissolve. The dissolved materials leach downward into lower horizons.
The next layer is the B horizon or subsoil. Subsoils are usually lighter in color, dense and low in organic matter. Most of the materials leached from the A horizon stops in this zone.
Still deeper is the C horizon. It is a transition area between soil and parent material. Partially disintegrated parent material and mineral particles may be found in this horizon.
At some point the C horizon will give up to the final horizon, bedrock.
Soil Zones There are many ways to classify soils and there are several systems in use worldwide. Most notable is the U.S. system of Soil Taxonomy. This system is used in many countries throughout the world but some countries – Brazil, Canada, France, Russia have developed their own systems. Regardless, all systems recognize the soil as a product of the environment and differ mainly in grouping and horizon definitions.
3.5 Give English equivalents: современная классификация почв, окружающая среда, производство с/х культур, строительство, недостаток серы, городской мусор, цвет почвы, по всему миру.