Environmentally significant indicators of mountain meadow soils in Azerbaijan

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Introduction. Azerbaijan possesses 9 of 11 world climatic zones, which are characterized by the development of unique and endemic soil types [1; 9; 11].

The meadow soil type was first studied in 1908 in Central Asia. The formation of mountain meadow soils is mainly on lyos rocks [8; 10].

The latitude and longitude of the study area is in this range E 45o 0'-47o 08' N41o 17'-40o 19'. Average annual humidity 75%, annual precipitation 600-900 mm. The average annual wind speed is 2.2 m/s [9]. Possible evaporation occurs at a distance of 1169-1119 mm from the surface of the coating. From April to November, there is more evaporation than precipitation, and the soil during this period experiences a lack of moisture. The groundwater level is deep [20].

Experimental part. Gadabay has its unique flora and fauna. Studies were carried out in the villages of Gara Murad, Saratovka, Slavyanka, Kichik Garamurad and river valleys (in 2017-2019 years). Herbarium materials were collected and the floristic composition was determined, soil samples were also taken from cuts up to 1.80 meters deep for laboratory analysis. In order to highlight the important role of vegetation in the process of soil formation and especially in the formation of humus, the surface phytocomplex and root mass of plants were determined in different seasons of the year. The amount of phytomass was determined once a year during the period of maximum vegetation development (end of May). The determination of the aerial parts of plants was collected 5 times in repetition from 1 m2 of area. The grass was cut 2 cm above the soil surface, sunflowers and grapes were harvested, dried in the open air, and then the dry weight was determined. The number of plant species prevailing in the collected herbarium materials was determined. There is no forest cover in the river basin. Water samples were taken with a bathometer in the part of the river Zayamchay, Cehrichay passing through the study area, mineralization and quality analyzes were carried out in the laboratory to determine their suitable for irrigation [21]. Both of them a stormy and abounding river. At each selected site, soil sections were laid down to the depth of the parent rock. In quiet sections, samples were taken for soil analysis (fig. 1, 2). Totally 15 land plots were laid. Some of the physical and chemical parameters characteristics are shown in the following tables (tabl.).

 

Table

Average indicators of the chemical composition of the soil, %

Soil depth	Humus	P	Na	N	pH	SO4	Ca	Mg	Cl
0-16 sm	3.27	0.26	2.35	0.39	7.8	1.895	0.010	0.005	0.32
16-37 sm	2.32	0.22	2.12	0.23	7.9	2.394	0.008	0.002
37-58 sm	1.81	0.20	2.97	0.37	7.5				0.4
58-77 sm	1.17	0.13	2.13	0.21	7.4	0.167	0.012
77-118 sm	0.68	0.09	2.18	0.32	7.5
118-152 sm	0.25	0.11	3.08	0.20	7.3	1.707	0.021	0.004

 

In several villages of the Gadabay region, soil samples were taken from soil crops and their physico-chemical properties were studied. The studies were carried out in different seasons of the year both in natural and cultivated cenosis. At the same time, the quality of river water passing through the territory of the Gadabay region and used as irrigation water was studied [5; 7].

Gravitational analysis of water (brief and complete) – E.B. Arinushkina, water-physical properties (hygroscopic moisture) – N.A. Kaczynski; absorbed bases – K.K. Hedroits; carbonates CaCO₃ and CO₂ – with a calcimeter; The content of total nitrogen and humus – Tyurin's method; with pH ionometer-pH meter; ratio C:N – CO2 according to the Tolubev method [17-21].

Discussion of the results. The most intensive decomposition of the remains of cereal vegetation is observed in the soil of the coastal strip – 65.9%. Such an intense decomposition of the substance can be explained by sufficient aerozation of soil horizons and the active oxidization of plant residues by atmospheric oxygen. In the natural cenosis, the destruction rate of saltwort and salt-tolerant grass vegetation reaches 44.3% in the processing of plant residues, the main role is played by a group of saprphages Hemilepistus woodlice, which actively drag the plant decay and the decomposed material reaches its final stage of microbiological transformation [12-15].

Carbonization is observed along the profile, starting from the surface of 0-25 cm. The rest of the salts and compounds were washed off the profile. Gray soils are prone to salinization. The soils of these and other territories differ depending on the conditions of soil formation and the natural cenosis. The results of the analysis of seasonal studies of the content of nutrients in dependent particles of irrigation water show that a significant amount of nutrients is introduced to the fields by dependent water particles. This has a positive effect on the fertility of irrigated lands and an increase in their productivity Saratovka, 1340 m above sea level. 250 m east of the gorge southwest gentle undulating slope, rocky pastures [16].

Ca⁺² and Mg⁺² in mountain meadow soils gradually increases from the upper horizons 0.010-0.002%, to the lower 0.027-0.004%. The Na+ content also increases from the upper horizons of 2.27% to the lower ones, amounting to 3.08 %. On the agrocenosis of forage plants, the content of Ca⁺² and Mg⁺² cations along the profile is much higher than in virgin soils of the natural cenosis. The total amount of Na⁺ and K⁺ increases both in the upper horizons and in the lower horizons. In mountain meadow soils of natural and cultivated cenoses, the pH changes between 7.3-7.8.

The following chart shows the percent of humus, dry residue and total salts in mountain meadow soils of Gadabay region (fig. 1, 2).

 

Fig. 1. Change in the content of organic and mineral components depending on the horizon

 

The activity of the catalase enzyme involved in the oxidation reactions of organic residues in the soil with sagebrush-ephemeral vegetation – 2.30 ml O₂/g. soil. Indicators of the enzyme invertase gradually increase in biotopes far from populated areas and reach 3.40 mg.gluc./g.soil in 24 hour. Determination in soil samples of the same biotopes of the activity of another hydrotic enzyme urease involved in the transformation of more complex compounds. if in the soil developing under saline vegetation its indicators (in a 0-30 cm layer) vary between 0.2-0.6 mg, then in the soil under halophyte grass vegetation, the activity of the enzyme increases to 0.4-1.1 mg NH₃/g.soil in 24 hour. In general, the hydrolytic activity of invertase and urease enzymes in the studied soils can be assessed as very weak.

Еhe activity of the enzyme was significantly influenced by the growing vegetation, the root system of which and their remains not only improve the soil structure and aerobicity, but also enrich the soil with organic components stimulating biochemical processes and their oxidative-hydrolytic transformation [17-19].

 

Fig. 2. Points of soil cuts and collected phytomass in the villages of Gadabay region

 

From 1 kg of soil at a depth of 0-25 cm, 8.2 mg of CO2 was released, at a depth of 6.8 mg of CO₂ 20-50 cm in 1 hour. From a characteristic sample of soil crops laid on dark mountain meadow soils, 14.6 mg/kg.h of CO₂ was isolated from a depth of 0-25 cm, and 11.0 mg/kg.h from a depth of 25-50 cm. In irrigated measow soils, from a sample taken from a depth of 0-25 cm and from a depth of 25-50 cm, CO2 was released 17.6 and 11.9 mg/kg.h. As depth increases, the amount of carbon dioxide decreases.

Conclusion. River Cehrichay has 7 tributaries, the self-regulation coefficient is 0.67. The volume of annual imports is 28.000 tons. The degree of mineralization river Zayamchay varies from 140 to 430 mg. The waters of these rivers are irrigation waters, which are dominated by calcium carbonate. In river sediments, the content of absorbed bases does not change in contrast. The content of Mg⁺² and Ca⁺² cations is 4.3 mg/ekv and 9.6 mg/ekv. It was revealed that the activity of catalase in natural cenoses of the studied soils varies between 2.03-2.80 ml O₂/g.soil, invertase 3.80-6.90 mg.gluc./g.soil and urease 2.88 mg.NH₃/g.soil. A close correlation was found between soil moisture and enzymes (catalase, invertase) respectively, for cenoses 0.59-0.84; 0.66-0.89; and 0.74-0.94; 0.67-0.98 and 0.7-0.80. Average annual humidity 75%, annual precipitation 600-900 mm. The average annual wind speed is 2.2 m/s. Ca⁺² and Mg⁺² in mountain meadow soils gradually increases from the upper horizons 0.010% – 0.002%, to the lower 0.027% – 0.004%. The Na⁺ content also increases from the upper horizons of 2.27% to the lower ones, amounting to 3.08%. On the agrocenosis of forage plants, the content of Ca⁺² and Mg⁺² cations along the profile is much higher than in virgin soils of the natural cenosis. The total amount of Na⁺ and K⁺ increases both in the upper horizons and in the lower horizons. In mountain meadow soils of natural and cultivated cenoses, the pH changes between 7.3-7.8.

The herbarium was collected and the dominant floristic composition of natural cenosis was determined: Vicia faba L., Taraxacum officinale F.H. Wigg., Artemisia vulgaris L., Anthemis candidissima Willd. ex Spreng., Veronica vulgaris Opiz, Galium tricornutum Dandy, Cynodon dactylon (L.) Pers., Daucus carota L., Trifolium medium L., Avena sativa L., Apium graveolens L. and others.

Invertebrates were collected and the dominant composition of the fauna of natural cenoses was determined: Tettigonidae, Hemiptera, Cerambucidae, Tenebrionidae, Coccinellidae, Cryllidae, Castropoda, Arachnidae, Alleculidae, Diptera, Isopoda, Lumbricidae, Carabidae, Curculionidae, Lepidoptera and others.

Therefore, agriculture has a positive effect on soil processes. The roots of vegetables and cereals determine the high productivity of the aboveground mass.

About the authors

Sima M. Talibi

Azerbaijan National Academy of Sciences

Author for correspondence.
Email: turkanhesenova@mail.ru

канд. c.-х. наук, ведущий научный сотрудник лаборатории

Azerbaijan, Baku

Turkan A. Hasanova

Azerbaijan National Academy of Sciences

Email: turkanhesenova@mail.ru
ORCID iD: 0000-0002-5040-2599

Ph.D.

Azerbaijan, Baku

References

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