Soil mass has outward appearance like each natural body. General view of the soil is separated to some generic layers depending on colour, structure, compactness. Such genetic layers in fully developed soil are 4 kinds. The most top layer of soil is marked with "A" letter. This layer is called "accumulative" rotting layer. As a whole, at top layer of soil as we know rotten organic matters are accumulated, so this soil is called as given above. As exceptional case, in podzol type soils top layer of soil is called as elluvial rotten layer. Such case is found mostly in thin top forest layers, which is marked as "Ao" letter. Second layer of soil is called as "elluvial" layer. “Elluvio” is a Greek word, which means "washing off". As the second layer is subjected to influence of both sol solutions and water coming down from top layer and so this layer is called as mentioned above. The 2nd layer of the soil is marked with "B" letter.
3. The 3rd layer is illuvial layer. İlluvio is a Greek word, which means “gathering”. To be true some matters washed away from top create 3rd layer gradually being washed. This layer is marked with "C" letter, too.
The 4th layer of the soil consists of sometimes from crystalline mother rocks, sometimes sediments of erosion and sometimes weakly eroded products. This layer is called “mother” layer and is marked with "D" letter. Each genetic layer that we noted above depending on morphological signs, are divided to some sub-layers. At that are marked with A1 A2 A3 -B1 B2-C1 C2 C3 D1 D2 letters.
Accumulative rotten layer A I A1
A2
A3
Elluvial B II B1
B2
İlluvial C III C1
C2
C3
Mother D IV D1
D2
As given layers have interrelations from creation viewpoint these layers are called generic layers.
Having of 4 generic layers in each soil type is not obligatory. e.g.: accumulative rotten layer in mountain–lowland soils is created directly on mother layer. Such type of soils has two, three generic layers.
In saline soils in most case no elluvial layers are found.B According to it each layer type has own specific outward appearance. E.g: in podzol type of soils there are thin accumulative layer, fully developed whitish elluvial layer, eluvial layer rich of iron oxide. Black kind of soils has very thick accumulative layer, clear granular structure and which peep-hole of Ca CO3.
At last, in chestnut type soils accumulative layer is 20-30 cm of thick and gradually passes to illuvial layer. As characteristic feature in illuvial layer of chestnut type soils one can sometimes find CaCO3 and sometimes new gypsum generations.
At last, in bog type soils one can find very thick peaty and greenish illuvial layer. This layer has more iron oxides; the layer creates new «Gley" formations, which are called as gley layer.
Skeleton of the soil.
One can find rock and mineral crumbs in soil layer inherited from mother rocks and they are called as skeleton of the soil.
Skeleton soil is called as stony soil. Basing on presence of skeleton in soil, in general soils are divided to skeleton, weal skeleton, and non-skeleton. Skeleton soils are mostly found in high mountainous regions and at foothill regions. But soils without skeleton are found developed in lowland regions. We shall be able to find genesis of the soil and from what rocks formed deeply learning the skeleton of the soil and its petrographic composition easily.
Classification of the soil.
Soil mass has own classification like each body (plant, animal, mineral), too. Classification of the soil has been built on 3 principles.
1.Spread soils reveal genetic signs each other.
2. Basic property of the soil reflects its productivity.
3. Depending on geographical situation it shows development and changing of the soil.
Scientists of Western Europe for the first time had proposed for the classification of the soil. We can show 3 trends in the soil classification in the Western Europe. Some scientists take as bases petrographic composition of the soil and in general divide them into granite, basalt and some other groups. Therefore this classification is named as petrographic classification of the soil. Another scientist Knop had divided soils in silicate, carbonate and ferrous soils be guided by the chemical composition of the soil. Therefore, such classification is called as chemical classification of the soil. At last 3rd groups of scientists:
Teyyer, Shubler had divided a soil into clay, clayey, sandy, sandy soils be guided by physical structure of the soil. It is called as physical classification of the soil. It is necessary to note that classification of the soil created by aforementioned scientists of Western Europe did not so prove in the rights in the soil science because these scientists had meant only one sign of the soil in the soil classification. They sometimes meant petrographic, sometimes chemical and physical compositions. Therefore, such classification of the soil had lost confidence soon. Basic genetic classification of the soil in the Russia for the first time had been proposed by professor Dokuchayev. This scientist looking at soil as natural body had meant factors forming it and he had created the genetic classification of the soil. Basing on wide researches professor Dokuchayev had divided all soils to separate types, which we noted below:
1. Heavy grey northern soil.
2. Grey soil.
3. Black soil.
4. Chestnut soil.
5. Brownish – saline soils.
By expansion of soil researches the soil researches by Dokuchayev was improved by his student and close employee by professor Sibirtsev. Basic soils named by Dokuchayev Professor Sibirtsev had included in "Zonal" soil group. Therefore Sibirtsev had united all soils in zonal, introzonal and azonal 3 big groups.
I-Zonal soils.
1) Laterit soil: such soils have spread in the countries with tropical and subtropical climates. Characteristic, formations of these soils are formed by direct participation of the tropical plants.
2) Eol-lös soil:- this type has spread in the continental countries mostly. They are soils with weakly developed and low level humus.
3) Desert – grey soils: such soils are found in countries with dry and low rainfall climate. It includes brownish-grey and chestnut soils.
4) Black soils: They spread in grey plains with moderate and hot climate. Such soils have very thick humus layer, clear morphological view.
5) Grey soils: it includes mountain forest soils in the moderate zone.
6) Podzol and fatty soils: They are soils which were spread in moderate, cold zone.
7) Tundra soils: Such soils have been spread in the zone of the coldest north.
II-İntrozonal soil: (it has been spread in the inside of the zone)
1) Saline soil: Such soils are formed in mother rock with participation of the salts.
2) Swampy soils: they are soils formed with direct participation of the very damp soils.
3) Carbonated rotten soils (Rendzin): Such soils are soils that formed on just carbonated rocks.
III Azonal soil: (it has spread in on the earth irrespective of zone)
1) Skeleton soil.
2) Young soils have been included here.
Zonal soils have been spread in the earth in the cases of definite zones by occupying wide geographical areas. In some cases "depressed place, more dampness, more saltiness of mother rock" forms another type of soil in the shape of spot in the inside of zone depending on changing of local condition inside of the zone, and it is called introzonal soils. One basic condition in formation of introzonal soils conformity of its development to zone. But azonal soils are soils that conform to zone but having no zonal spread. E.g. skeleton and weakly developed young soils are found in each zone. After Sibirtsev’s classification, in 1925 academician Hedroyts had put forward his classification. He had put absorption complex of soil in the base of his classification. According to absorption feature all soils have been divided into to two big classes:
1) Absorption complex is soils saturated by bases. Ca, Mg cations are in saturated condition in absorption complex of such soils.
2) But class soils are soils which were not unsaturated with bases in absorption complex. Hydrogen ion has been in the absorption complex of such soil. Hedroyts gives classification of the soil in the following form:
I. Soils saturated by bases.
1) Field type soils – absorption complex of such soils are always saturated with Ca and Mg.
2) Saline type of soil: absorption complex of such soils has Na cation besides Ca, Mg cations, too. Academician Hedroyts divides the saline type soils to 3 classes:
1) Stage. Saline and saline like soils: Such soils are mostly rich with salts easily solved in the water.
2) Stage. Saline soil: such soils are characterized with Na cation in absorption complex being weak than salts easily solved in water.
3) Stage. Malted soils: Such type of soil has no Na cation in absorption complex and is mostly characterized with SiO2 compounds.
II- soils unsaturated with bases.
1) Laterit type of soil: absorption complex of such soils are in broken condition. Mostly iron and aluminium (Al2O3) are spread in structure of these soils. But SiO2 compound is not described.
2) Podzol type of soil: absorption complex of such soils is saturated with H cation. But upper layers are rich of SiO2, and lower illuvial layer are rich with iron compounds. Besides Hedroyts professor Kasseyeyich had offered its classification of soil. This scientist had meant the physical and chemical property of the soil on the basis of classification. Kasseyevich had divided all soil to 2 types (in soil forming process) according to the reaction of the soil solutions:
1) Alkali type of soil: it includes saline, chestnut, black soils.
2) Acid type of soil: It includes podzol, bog, and forest and tundra type of soils. Professor K.D.Glinka had offered the classification of soil that we noted below takin in view the role of climate in formation of soils.
I-Laterit type of soil.
.
1) Typical lateris.
2) Red soils of the subtropical countries.
3) Red soils of the moderate hot countries.
II-Podzol type of soil.
1) Brownish forest soils.
2) Podzol glue (FO) soils.
3) Peaty podzol soils.
4) Hidden podzol soils.
5) Primitive podzol soils.
6) Meadow podzol and mountain meadow soils.
7) Blackish soils.
8) Repeated podzol soils.
III Grey type of soils.
1) Black soils.
2) Chestnut soils.
3) Grey soils.
4) Grey soil.
5) Red colour soils of subtropical and desert countries.
IV Swampy type of soils.
1) Peaty swamp soils.
2) Meadow swampy soils.
3) Saline soils.
4) Saline like soils.
V-Salty type of soils.
1) Washed saline soil.
2) Saline and saline like soils. It is necessary to note that this classification defined by Glinka had not lost its importance yet. It is possible to say that Glinka’s classification had covered all soil types spread on earth.
Geography of the soil.
Soil cover is subjected to 2 main groups in its geographical spreading.
1) It is horizontal spreading of the soil.
2) Vertical spreading of the soil.
If we move slowly towards south and south-east from North of the USSR we will see that soil cover depends on certain foreign factors and there will be clear strip type spreading. These strips were located in some physical-geographical areas of the USSR. Following strips are observed in horizontal spreading of soil in the territory of the USSR:
1) Tundra soil strip.
2) Podzol soil strip.
3) Black soil strip.
4) Soil stripe perches chestnut.
5) Grey soil Strip: Some saline soils have been spread here. Such changing of soil on earth is called as vertical law. But vertical law of the soil is observed in the mountainous regions. This law for the first time has been observed by professor Dokuchayev in the Caucasian territory. Vertical law is observed in Turkestan and Crimea besides the Caucasus. If we go on travel from plain foothill, medium foothill, high foothill zones gradually from sea level we will be able to observe that soil cover replace each other in separate strip form. So, changing of the soil as noted by us in the vertical law is affirmed in this circumstance, too. By passing plain regions to mountainous we will see spreading of brownish, chestnut, black forest and mountainous-meadow soils. Taking in view basic geographical spreading of soil one can define strips that we noted below in the territory of the USSR:
1) Tundra zone.
2) Forest podzol zone.
3) Forest-grey zone.
4) Grey or black soil zone.
5) Drought grey zone.
6) Desert zone.
7) Zone of red laterit.
I- In tundra zone most spread soils are tundra and swampy soils. Sometimes podzol soils are spread in the South edges of the zone in the form of some spot, too. From geographical viewpoint tundra zone occupy north part of Kolan peninsula and North Sea (ocean) coast, and thenmoves to south-east by occupying major part of Kamchatka.
.
II- In forest podzol zone: Here podzol type of soil is spread mostly. Main part of this zone is located in vast areas of swamp and semi -swamp in the north-east. It is possible to say that podzol type of soils has surrounded 3/4 parts of the territory of the USSR. South part of podzol zone covered Jitomir, Kiev, Tula, Ryazan, Kazan cities and north part of the Urals. Moreover podzol soils are most spread in Siberia, Far East and Yakutiya.
III - Forest grey zone: Soil of this zone consist of repeatedly podzoled north forest soils. It is noted sometimes that they are spread in saline and swampy soils.
IV- Black soil zone soil: Main soil cover in this zone consists of black type soils. Especially ordinary black soils are typical south, Azov shore soils. Black soils zone occupies south and south-east of the USSR area. This soil zone is considered as most spread in Western Siberia. Northern boundary of this zone passes through Kiev, Oryol, Penza, Ufa, Chelyabinsk cities and its southern boundary passes through Black and Azov seas shores and towards Volga River and Semipalatinsk city. Black soils are considered most spread soil in Urals, Baskirtistan and North Caucasus, too.
V-Dry grey zone: Dark, light chestnut and chestnut soil had been spread in the zone. Depending on drought of the zone and sometimes on the character of the rocks, glade type saline and salty soils were developed on these soils. From geographical viewpoint dry plain zone was located in the eastern part of the USSR, on the coasts of the Caspian Sea and south-eastern part and covers Caspian shore, further towards south-east and covers Kazakhstan. Chestnut type soils are found in Transcaucasia and Central Asia.
IV- Desert zone: This zone occupied by grey type soils, which covers vast areas. This zone is also considered as soils most spread in saline soils. It surrounds the part of the Turkmenistan, eastern Azerbaijan, North Caucasus, north-east part of the Armenia.
VII- Laterit and red soil zone: As there is tropical and subtropical climate mostly very strange laterit, yellow soils and red soils have been developed here. This zone has occupied a little area inside of the USSR territory. Such kind of soil is met in Talysh region of Azerbaijan and at shores of Black Sea, around Batumi and Sochi, especially.
I Tundra zone.
This zone is considered as least studied zone. Main feature of this zone is often negative temperature and long winter nights. Average annual temperature of the zone is below 0 (from zero) and amount of the rainfall is 200-300 mms. Falling of rainfall in temperature so low creates the condition that soils here are saturated by dampness. Sea sediments have been spread from mother rocks in the Tundra zone. Regarding relief small hills are spread here. From one side low temperature and from other side long days had developed plant’s growth.
From drying influence of north winds in some snowy naked areas upper layer of soil were covered by thin cracks. Such tundra is called spotted or bold tundra. Moreover, this 2nd type of tundra is hill tundra and it differs from first kind of tundra. Upper layer of this tundra was covered with peat hills of various size and shape. Surface of hills here were covered by moss. The most characteristic sign of the tundra zone, constant glacier is of the zone at last. Finally, the most characteristic feature of tundra zone is permanent glacier here. Thickness of frozen glacier in northern part of tundra is 30-40 cms. But in southern part frozen glacier layer is located rather deep. Therefore, in the most edge southern part of tundra zone in valleys of rivers one can find single tree plants. Depending on the natural condition like noted above, soil cover of this place consists of weakly developed primitive soil, peaty soil, soils of river valleys and swamps. Researches conducted recently had revealed that basic soil formation process here consists of gley-swampy soils. Therefore they divide the territory of all zones into two semi-groups:
1) Semi-zone is called factual tundra: Because of constant glacier here the given soil has been developed here.
2) Semi-zone occupies south part of this zone. Gley swampy soils have been spread here. One of characteristic morphological signs of the soil is presence of gley layer. It is possible to say except these soils no such amount of gley is found in so clearly and completely developed in other soil types. Hidden gley tundra soils are found in the second semi-zone. These soils had been developed under water-plant and moss. Hidden gley soils are considered as typical soil of 2nd semi-zone. At last, at river valleys one can find sometimes swamp podzol soils, too. Thickness of these soils “Profile” is very short. Thickness of "A" layer is 1-2 cms. But thickness of "A2" is 2-3 cms and thickness of "B" is not more than 5 cms. But average thickness of the soil is 30-40 cms
II Podzol zone
Primitive podzol soil had been spread in this zone. These soils are counted as from zonal soils of this area. Climate of the zone consists of follow:
Average annual temperature is 3. 5°-4°, rainfall 500-580 mms. Permanent saturated dampness in atmosphere of this place is usual case. Depending on this climatic condition soils of podzol zone are not only saturated by dampness but even subjected to washing off under influence of the dampness throughout the year. Regarding mother rock here one can find moren depressions, red clay rocks, lös rocks and sandy sediments. One of the main features in the structure of these rocks is presence of Ca, Mg compounds. Plant cover of this place sometimes consists of mixed forests (tree of fir-tree, pine tree) and meadow plants. Despite of low level of humus of podzol and soils abundance of plant remainders, formed humus is washed off.
