Summary
Major part (till70%) of the land of the Plain of Shirvan is not being used in the agriculture at present. Suffice of the water of irrigation in the existing rivers, repeated salinization in soils etc. cause obstacles to using of soil so area.
In connection with building of Mingachevir water reservoir laying of Northern Shirvan canal here will create opportunity for expanding of the areas of sowing which should be irrigated here and it puts learning of land-reclamation features of the land in this Eastern Shirvan as first-level duty. We began to study since 1952 this matter as nobody studied water-salt regime of soils in Eastern Shirvan. When we carried out the same investigation we deemed it necessary to characterize physical-geographical, chemical-geographical conditions both foothills and plain zones). Basing on this we determined chemical composition of the salts and its spreading in the profile of the land, geographic spreading in the region. Moreover we learnt the water regime of 16 stationer fields of the land in the Eastern Shirvan during 2 years. At last, we compiled land-reclamation map of the territory according to genesis of the salinization of the land of eastern Shirvan Plain.
We decided elucidating the method of making and giving the description of the each of the melioration regions separately before giving the explanation of the problems that we named above and land-reclamation map. Because problems mentioned above will be elucidated though in brief.
We have compiled the land-reclamation map of the land of Eastern Shirvan region taking into account the following factors. First of all, we decided to give in depth geomorphologic and geologic features, lithologic and chemical composition of lands and rocks, feeding source of the soil waters and its flow condition, degree of mineralization and chemical composition. Then we gave amount of separate salt components (HCO4, Cl, SO4, Mg, Na+K), later types and salt profile of saline soils’ distribution, area wise spreading of salts, its evolution regularities connected with natural conditions and salt system regions.
Then we tried to determine a role in gathering of the salts in separate sources and its importance. For these purposes we have determined the ways of changing of the water regime in our two years stationer observations, its dynamics of mineralization. Taking into account factors shown in all above, we come to conclusion that there are following land-reclamation regions in Eastern Shirvan.
1. High plateau surrounding Garamaryam region. Land of here is not saline. The area was drained (was divided into plotocon ion type deep antecedent holes).
In upper 70 cms layer of soil dampness is very dynamic. This layer is characterized with long time (winter-spring months) high amount of (25-30%) of the dampness.
2. Upper part region of the cones brought by river. Land of here is not saline. The underground waters settles are located in the deep. Land in many circumstances is clayey and saline. And it creates some difficulties in its cultivation. Salts on profile in low amount in soil were distributed equally. Salinization of soils is hydro carbonate-calcium, hydro carbonate-suplphate and calcium-natrium according to the composition of the salts. Salts are less dynamic in the raw lands on seasons.
Usually their amount varies between 0.1-0.2%, which is characteristic just for 20 top cms layer. But dynamic of the salts is observed in the areas put untouched in the lower layers of the soil. Such circumstance is only characteristic for some seasons of the year. Land of the irrigated areas is characterized with washing of their top layers from salts and by gathering of the salts in lower layers.
It is possible to say that water regime of the soil that high humidity (20-35%) is observed in 50 cms top layer of the soil in this region that this is very specific for autumn, winter and spring months. But in layer of 50-200 cms the amount of the dampness, almost varies between 10-20%.
All this shown features create opportunity for use in the wide scale of the land of the land-reclamation region that we described, but majority of the land of the area is used for cotton wheat and for gardening.
3. Middle zone region of cones brought by rivers. Soil waters here are located near to semi-must layer of land. Relief of the area has been expressed clear and its soils are saline. Because water permeability of the soil is good so, it caused location of soil waters in some shallow areas (0.5-2.5m in the depth). Soil waters have at the same time become strong saline (20-80% g/l). Here saline soils are met in these areas. Lands are very sulphate-manganese, calcium-natrium salts.
Soil waters according to the humidity in the areas are located shallow; it is possible to say that all profile of the land has eaten enough all the year round with dampness. Such circumstance is observed even in the months of summer. Becoming much salty in summer months in such situation causes its much salinization in summer months but according to result of observation that we carried out the humidity in spite of much salinization of soils in summer months in winter months those salts are washed easily. Such situation shows that washing and improvement of same soils is easily implemented.
4. Region of repeated alluvial-proluvial cone brought by rivers. Soil waters are observed here in the depth and they have become less saline because they are located in depth. In spite of becoming less salty in the same area of the top layers of the land, in many cases it is noted that there is considerable amount of salts (0. 5-1.5%) in their lower layers. Lands are saline with hydro carbonate-sulphate-calcium and natrium salts. Bu water dynamics of the land shows that humidity of the land is in impermasid character in of the soils put untouched. So amount of mineral dampness of soils of this 80-200 cms layer almost is not more than -10% thru the year.
Therefore to use these lands effectively it is necessary to bring humidity amount by 20-30% in vegetation in lands by the irrigation way. As it is shown in water dynamics of lands under irrigation good harvest can be taken from lands. Cotton, wheat, grapes are grown in the described area.
5. Daisy zone region with relatively hard mechanical compositions and saline soils. Soils of this region are very heavy for melioration properties. Crusty and hard lands have been spread here in the wide scale. At the same time illuvial layer of these lands became solid. Cultivation of this type of soils creates obstacles for development of the agriculture plants. Amount of salts in the layer of plant roots of the land varies between 0.12-0.77%. But this amount is more (1-2%) in the lower layers of land. Results of stationer observations show that in upper 1 cms layer of these soils amount of slats increases year by year. It is explained with flooding of this area by Garasu from time to time. Water permeability of this region is low.
Chemical composition of the land is different, with sulphate-chloride-natrium; amount of the dampness does not exceed 10-20%-dən in the land during year.
All these aforesaid require implementation of full-fledged land-reclamation works for total usage of soils of the region. To our mind, it is expedient to carry out land washing works here. In this case it is necessary to give gypsum to soil and to make sowing layer of soils deeper that clayed layer of soil be tuned to sowing layer. Because there is salinity in illuvial layer. During having such measure as soil and ground is clayey it will be necessary to make small drainages here.
It is required to remove water passed into soil in this process of washing.
6. Qarasu surrounding region with clear mezzo relief of hard mechanical component with very saline soils. Land of this area, it possible to say that all soils here are hard clayey and water permeability is weak. They are at the same time much saline, and it is met in most cases in saline soils. Being of the saline land is characteristic for this area. Soil water has been located in the shallow and (2.3-5m of the depth) differs with much salinity (25-40 g/l). In connection with flooding of this land from time to time salt profiles of various forms are met in this area..
Always being under capillary influence of the soil waters of the land causes remaining of their layers with saturated condition from water (20-30%) during the year.
Dynamics of the subsoil and soil water shows that during summer level of subsoil water rises and salinity of subsoil waters increases and amount of salts in layer of feeding of plants in soil. In winter and spring months in connection with relatively heavy rainfall salts gathered in layer where plants are being fed, is washed by sub layers. Land of this region needs work on fundamental land-reclamation.
7. Soils with hard mechanical composition, relief with saline and clearly expressed soils, with hard mechanical composition, Heavy land where/which have/has become salty with mechanical component and clear relief. This region surrounds the east part of the daisy zone. Soils of the region are very hard for land-reclamation feature of land. Lands are clayey. Soil waters are located shallow and very salined.
Saline lands have been spread in all territory. Salts in these lands are gathered in some periods at upper layer. Soils here are chloride-calcium-natrium and salined with much chloride salts. According to land of the territory, their gypsum feature, none of agricultural plant is used for sowing of plant. Saline and bog plants have prevalence in the natural plant cover of the territory.
8. The dealluvial-proluvial inclined plain region with salined lands. This region covers remote foothill part of the zone, plain of less sloping dealluvials and high dealluvial-proluvial terrain. In some parts of region soils are fed with saline subsoil waters went on surface due to tectonic violations.
In this connection soils of our described region were considerably salined in much area under influence of dealluvial sediments. Amount of the salts below salt profile of 30-60 cms depth increases sharply. Saline lands are spread in separate areas. It is salined with manganese-calcium and chloride–sulphate, calcium-natrium has become salined. Last type of saline soils mainly is located in the lower places of the territory. Major part of land of the region that we characterized is not used for agricultural purposes due to lack of water and salinity of soils. Their washing is required completely for usage of these lands. But washing of the land creates some difficulty because lands are clayey, hard and saline.
It is expedient to have tillage be ploughed without turn of layer and then washing of these lands is purposeful for good usage of these soils. So, when tillage turned salts in lower layer of the land passes to upper layer and upper salined layer goes to beneath of tillage layer and finally all salts passed to upper surface of the land are to be washed again. Therefore lower layer of these lands is very saline and as upper layer is not saline it is purposeful to not turn tillage layer.
9. Ancient Caspian terrain- Padar oval region. Soil waters are located here in depth, and process of malting is observed here. Top layers of the land here is not saline but it has become salty in deep layers. Territory is used for hayfield. Shortage of the water prevents to use these lands for sowing of agricultural plants.
10. Padar (contact) depression region. Land of this place has become much salty. 30 cms of top layer in salt profile of soils is not saline. But in lower layers salts have prevalence. Shortage of the water and high salinity of soils, no agricultural plants are grown in this area. But they are used as hayfield in many years here.
So, it is determined that land-reclamation feature of the land of Eastern Shirvan is very complex and very different. It is explained, first of all, with wide spreading of saline soils, salinization and bogging factors of soils, diversity of hydro-geological oval condition, bad agro physical features etc. All these demand different and complex land-reclamation works in the studied region.
