This article presents the results of scientific research; one of the goals is to survey pastures to monitor natural soils, analyze soil and meteorological conditions, and also to identify the features of secondary successions arising from grazing during the overgrowing of deposits in the grass ecosystems of the Northern Kazakhstan.

Materials and methods

The objects of research are the vegetation of grass ecosystems and the change in its productivity during succession in the dry-steppe zone of the Northern Kazakhstan. Key areas of grass ecosystems of different types of succession are located in Akmola region.

For the survey of pastures, the following farms were identified: the scientific and experimental campus of JSC ” S. Seifullin Kazakh Agrotechnical University”; LLP “SC Food” Akkol district of Akmola region; LLP “Agrofirma BaiZher" of Tselinograd district of Akmola region; JSC “Akmola Phoenix" of Tselinograd district of Akmola region. The experimental sites were selected by conducting a detailed analysis of vegetation, species composition, yield of the association, habitat conditions in accordance with the method of the pilot case [1, P.419], [2, P.42]. To study, natural or seeded grass stands were taken which were created in different years by sowing grass mixtures with the use of varieties regionalized in the region (Fig.1,2).

Fig.1 - Experimental pastures. Survey of pasture

Fig.2 - Experimental pastures Experimental plots

The results of the studies obtained by Professor Stybaev G. Zh. in 2001-2009 show that the recommended methods for improving the steppe degraded pastures are effective, economically viable and suggest the expediency of phytomeliorative work. Spent amount pays off in 3-5 years, which is cost-effective [3, P.30]. Thus, based on surveys and experimental studies and generalizations for the dry-steppe zone of the Northern Kazakhstan, the following techniques are recommended for improving natural fodder land. For severely damaged and degraded pasture located near villages, it is necessary to make a superficial improvement by sowing perennial grasses, removing from circulation for 2-3 years. In order to improve the water-physical and agrochemical properties of steppe pastures, it is advisable to test strip plowing with a width of 3.5 m in 15 meters. Surface improvement of steppe pastures should be carried out by loosening for 10-12 cm, in the first half of May with the sowing of alfalfa-wheat grass or wheatgrass-bluegrass herbage mixture [4, P.1-4], [5, P.1-2], [6, P.1-3].

However, with the use of certain technologies, it is necessary to monitor pastures which are not fully implemented in farms, and as a consequence, use the wrong selection and sowing of grasses, etc.

Characteristics of study areas

The average daily air temperature in winter months, in comparison with the average long-term mean daily temperatures, was colder in January by 6.4, in February by 0.8° C and correspondingly made up 21.4 and 15.5° C. In spring months in March and in April, the average daily air temperature was at the level of the average annual data and made up to - 8.3 and 4.2° C. However, the average daily air temperature in May, in comparison with the average long-term average daily temperatures, was lower by - 4.2° C and amounted to 8.9° C (Table 1).

Table 1 - Average daily air temperature in winter and spring months in comparison with the average long-term values, єС

The precipitation in January was higher than the norm by 3.3 mm, and amounted to 21.6 mm, and in February it was 9.1 mm less than the norm. The precipitation of spring precipitation by months was observed in the following numbers: in March, 37.9 mm, in April - 50.5 mm and in May - 35.8 mm, and, respectively, exceeded the mean annual indicators by 21.0, 30.6 and 2.0 mm (Table 2).

Table 2 - Amount of precipitation in winter and spring months in comparison with the APR, mm

Productive moisture in the meter layer of the soil of the scientific and experimental campus in May was at a high level of moisture, and amounted to 150.5 mm, while the density of the arable layer (0-30 cm) of the soil was medium-dense, and amounted to 1.10 g/cm³. In the conditions of LLP “SС Food”, productive moisture in a meter layer of soil was at an average moisture level of 107.1 mm, density of the arable layer of soil was medium-dense, and amounted to 1.14 g / cm³.

Due to the abundance of spring precipitation, the productive moisture in the meter layer of soil in JSC “Akmola-Phoenix" in May was at a high level of moisture - 158.9 mm. In the conditions of LLP “Agrofirma Bayzher" productive moisture in a meter layer of soil was at an average level of moisture, and amounted to 108.6 mm.

To determine the agrochemical composition of soils in the period before sowing of perennial crops, soil sampling was carried out with a special Izmail borer. These soil samples were prepared by drying and sieving to the analysis of the determination of the agrochemical composition.

The chemical analysis of the soil was conducted in the laboratory of the Center for Agrobiological Research. The main indicators in the layer of soil 0-20 and 20-40 cm are shown in Table 3.

Table 3 - The results of the chemical analysis of the experimental plot

The analysis of meteorological conditions was carried out monthly, while daily data on farms are recorded at the following meteorological stations:

in the scientific and experimental campus - the meteorological station “METEOS”;

in LLP “SC Food” - Akkol weather station;

in LLP “Agrofirm BayZher" - Novoishimskaya weather station;

in the JSC “Akmola-Phoenix" - weather station in Astana.

Monitoring of natural pastures, with the determination of the plant species composition of the experimental plots, was carried out in 4 farms, in accordance with the methodology for conducting ecological monitoring in pastures (Fig.4).

Fig.3 - Selection of plant samples

Conducted surveys of the geobotanical composition of pasture areas, as well as phytotopological and phytocenological assessment, showed that the soil cover of pastures is represented by dark chestnut, non-white alkaline, white alkaline, medium-thick and low-power soils. The soil cover of the surveyed pasture areas was covered by vegetation from 82.7 to 88.2%. By type of appearance, the botanical composition is 65% which is composed of plants with a top type of lining and 35% grass-roots type. The surveyed areas of natural pastures refer to a grass-and-herb type with haymaking and grazing use, ensuring from 1.9 to 5.3 tons per hectare of pasture weight per unit area during the growing season under moderate conditions of moistening.

Botanical composition of vegetation plots in LLP “SC FOOD” of Akkol district, LLP “Agrofirma BayZher" and JSC “Akmola-Phoenix" of Tselinograd district of Akmola region was represented by various plant species (Table 4).

Table 4 - Botanical composition of grassland pasture areas in LLP “SC FOOD” of Akkol district, LLP “Agrofirm BayZher" and JSC “Akmola-Phoenix" of Tselinograd district of Akmola region, the average by samples

On the plots, such plants as the crested wheat grass, blue alfalfa, wormwood, tall brome and yellow bedstraw prevailed.

Projective coverage of pasture areas by households varied from 82.7 to 88.2% (Fig.4).

Fig.4 - The average indicator of the projected coverage of pasture grassland, %

At the same time, there is no direct connection between the projective cover and pasture areas, the correlation coefficient is - 0.997.

It should also be noted that the yields of the surveyed areas, depending on the botanical composition, varied from 1.9 to 5.3 tons / ha (Table 5).

Table 5 - Yields of pasture and air-dry herbage of pastures

Thus, the highest yields of the surveyed pastures were recorded in the conditions of LLP “Agrofirma-Aktyk” of the Tselinograd district of the Akmola region.

During studies, the root remains of herbaceous plants were studied, by taking into account the root residues using the frame method of root extraction by the method of N. Z. Stankov (Fig.5,6). The amount and composition of the root residues were determined in the 0-10, 10-20 cm layers on the variants. The mass of roots and its relation to the aboveground mass is determined by the presence of nutrients in the soil. With the increase in the availability of plants with elements of mineral nutrition, the total mass of roots in the soil increases and their share in the total biomass of the plant decreases. That is, the growth of the root system, its extent and mass is determined by many factors, one of the most important among which is mineral nutrition. The effect of stubble and root residues on soil fertility is determined not only by their quantity, but also by the chemical composition and nutrient content in them [7, P.125].

The weight of the green mass of plants was determined at three points of the plot of each farm - on the plots of radical improvement, fallow and pasture.

Fig.5 - Cut off aerial part of plants for analysis

Fig.6 - The process of washing root residues (manually)

The increase in accumulation in the soil of the root mass, as well as stubble residues, contributes to an increase in the fertility of the washed-out soils. The roots of plants have selectivity, so they are formed in a larger mass where there is more moisture and nutrients. If the fertility decreases in the lower part of the arable layer, then the plants create more roots in its upper part.

Results of the study and their discussion

The main factors of the ecological distribution of herbs are the degree of water availability of the soil and salt concentration of the solution. These factors, with their wide variability in space, determine the difference in conditions of diffuse exchange in plants, respectively, their biological fitness to the prevailing pressure of the soil solution.

The grass stands on white alkali are poorer in species composition, often with motley grasses. The yield of which makes up 3-5 centners per hectare. These pastures can be used from spring until late autumn to graze animals. According to its composition, the herbage is herbaceous, grass-mixed, resembles meadow steppes with about the same yield.

In this regard, scientists of S. Seifullin Kazakh Agrotechnical University conduct research in the framework of a grant project, the goal of which is to develop ways to manage the succession of phytocoenoses in hayfields and pastures and increase the sustainability of their productivity in the dry steppe zone of the Northern Kazakhstan.

Deserted parts of the steppes occupy 60-70% of the area, of which 30-40% are white alkali and saline, mainly with saltwort vegetation. Soils are light chestnut, usually of varying degrees white alkali, complexed with white alkali and saline. The most common steppe pasture grasses in the semi-desert zone are feather-fescue, tyrasak-fescue, mixed feather - fescue, sand-feather - fescue to some extent poured. Among motley grasses there are fleawort, Jerusalem sage, goldilocks, allium, yellow alfalfa, pyrethrum, artemisia (worm seed), Austrian and narrow-lobed on these pastures. Plants of an etimeric type such as bulbous bluegrass, desert borage are mixed on white alkali soil differences. The yield of the mass of eaten plants varies from 3 to 5 centners per hectare.

The climate of the dry-steppe zone of the Northern Kazakhstan is dry and continental, here there is a significant variability in precipitation and thermal conditions, both over the years and within the summer season. The difference, in the amount of precipitation, by years from 1935-2008 is determined by the ratio 1: 12 (150 and 190 mm). The value of the HTC (hydrothermic coefficient) in the summer months of 2003-2017 is a difference from 0.3 to 1.9 In average multi-year indicators, the value of the HTC is more favorable for the second half of the summer than for the first half. The culture of perennial grasses with such variability of the hydrothermal regime has, in general, more favorable conditions compared with all annual crops [8, P.1-4], [9, P.114].

The total determination of the productivity of the natural vegetation cover of the steppe zone of the Northern Kazakhstan (pasture potential) gives an interval of fluctuations in the yields of grasses in time and space in the range 1.0 - 2.4 c / ha dry mass, which is the result of many years of unsystematic use of the natural system leading to degradation. The latter is exacerbated by an extremely tense regime of moisture supply and low fertility of meadow white alkaline complexes.

A scientific prerequisite for the improvement of steppe pastures was an increase in the floristic and phytocenotic abundance of some plant communities.

Radical transformations of steppe (degraded) pastures to a new highly productive fodder area, possibly by superficial (1 and 2 soil-reclamation) improvement. The time of loosening of these soils is the end of the ten-day period of May, followed by herbage. Disk tools are used on soils where the work of cultivation is difficult or impossible [10, P.1-4].

The decrease in the quality of pasture lands, their yields, and as a result, the reduction of the feed base in the Republic of Kazakhstan leads to the decline of the livestock sector. The results of studies conducted in 2001-2009 by Professor Stybaev G. Zh., Astana, Kazakhstan, were the basis for further research on the succession of vegetation in the dry-steppe zone of the Northern Kazakhastan.

In each locality, key plots (ranging from 1 to 10 hectares) were selected representing a certain stage of the succession under study. The species composition of the vegetation of these areas and the initial ecosystem was described, as well as the soil and the type of impact. In the study of successions, we used a change in three main indicators: a change in the species composition of communities [11, P.16]. Change in the structure of dominants [12, P.438]. Changes in phytomass stocks and its structure [13, P.216].

Sustainable pasture of the LLP “SC Food” of Akkol district of Akmola region is characterized by a constant high pasture load. The pasture of the scientific and experimental campus of JSC ” S. Seifullin Kazakh Agrotechnical University” was at the stage of digression, in 2017 the pasture was completely abandoned and its vegetation began to recover gradually.

Pastures of LLP “Agrofirm BayZher" and JSC “Akmola Phoenix" of the Tselinograd district of the Akmola region were under heavy load for several years. The steppe is used as a winter pasture.

The study of pastures has shown that there is a direct link between the change of pasture impact and the response of pasture. The analysis carried out for such indicators as the change in the species composition, the pattern of species dominance, proves the close relationship of all phytocoenosis indicators with pasture load. For any change in the mode of grazing, the phytocenosis corresponds to regular changes in its species composition, the structure of dominance, and the intensity of the production process.

Conclusion