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Isagaliev Murodjon, head of Soil science department, Fergana State University, E-mail: [email protected] Yuldashev Gulyam, professor of Soil science department, Fergana State University E-mail: [email protected]
Abdukhakimova Khusnida, postgraduate of Soil science department, Fergana State University E-mail: [email protected]
GEOCHEMISTRY OF BIOMICROELEMENTS IN IRRIGATED SEROZEMS IN THE SOUTH OF FERGANA
Abstract: The article presents the biomicroelements composition of irrigated soil in the serozems zone in the south of Fergana. According to the content of microelements, serozems to the depth of the parent rocks are arranged in the following order: dark>typical>light. In the horizons of serozems according to Clark, the concentration of the studied microelements occupy the following row: B>Mo>Zn>Mn>Cu.
Keywords: serozem, content of biomicroelements, honey, zinc, manganese, molybdenum, boron, migration, geochemical province, concentration, Clark concentration.
Introduction. The prevalence of biomicroelements in one or another systems of nature is the most important characteristic, which reflects their role in the genesis of this system. Comparison of common biomicroelements in soil and soil-forming rocks of the object of study and plants allows us to consider and evaluate the influence of biomicro and macroelements from biogeochemical positions. The interest to biomicroelements is caused by their participation in the most important life process - exchange substances.
Back in the early sixties, A. E. Fersman [1] wrote that human economic activity in its scale and significance had already become comparable with the processes of nature itself.
The studies of V. V. Kovalsky [2], B. A. Yagodin [3], V. I. Panasin [4], G. Yuldashev and M. T. Isagaliev [5] proved the high physiological role of microelements in living organisms and their influence on soil fertility, yield and quality of crops. Their specific influence on the character of the synthesis and function of many biological active substances of plants and animals has been established.
Lack or excess of elements in soil and food, drinking water causes endemic disease of animals and human.
At present, in Uzbekistan a small number of chemical elements are successfully used in practice for regulating metabolic processes in order to improve the quality and increase the productivity of agricultural crops. Their additive to min-
eral fertilizers can cause certain changes in chemical, biogeochemical regimes of soil and plants.
A large number of works by D. Sattarov [6], A. Shamu-ratova, D. Sattarov and others [7] are devoted to this issue, where it is stated that the introduction of a small amount of micro fertilizers significantly affects soil fertility and the purposeful formation of agrochemical backgrounds for enable growth and plant development.
Solving these problems is almost impossible without knowing the level of chemical elements in soil and plants, especially those that play a special role in plant life. Currently, a direct link has been established between the content in the environment (in soil and water) of microelements (Mn, Cu, Zn, Mo, B, etc.) and photosynthesis, protein metabolism, growth processes, plant resistance to adverse environmental factors, such as lack of moisture, elevated or lowered temperatures, resistance to disease, etc.
Since microelements play an important role in the fate of living organisms, the latter ones react sensitively both to deficiency and to excess in the environment. Consequently, the study of these trace elements biogeochemical point of view is an urgent problem of irrigated agriculture and soil science.
Object and methods of the research. Trace element analysis of soil and gross and mobile forms of trace elements in soil were determined by the Kruglova and Verigina method,
Section 1. Biology
the object of research is irrigated dark, typical and light sero-zems formed on loess and loess loams in south Fergana.
Results of the research. Any fluctuation in the content of elements in soil, and sometimes in soil-forming rocks, even in irrigated water, can cause changes in the chemical composition of the plants growing on them. While investigating soil and plants first of all elements such as Cu, Zn, Mn, B, Mo took our interest. As it was mentioned above these elements play an important role in the life of plants, as a certain physiological and biochemical role.
A study of the distribution of copper in soil has shown that dark gray soil are relatively rich in this biomicroelements. The parent rocks of the studied dark, light, typical gray earth contain almost the same amount of copper, where its gross form varies, respectively, in the intervals of 10.3-11.7 mg/kg.
As for the arable horizons of gray soil, here and in other horizons to the depth of the parent rocks according to the copper content, the dark>typical>light serozems are arranged in the following order. But at the same time, copper fluctuation in the serozem profile is 21.2-29.5 mg/kg. A relatively low content of mobile copper occurs in all subtypes of serozem, but the tendency to reduce its content from dark to light serozem persists.
Elementary landscape largely determines the level of content of mobile and gross forms of biomicroelements in soil blocks. The content of copper and molybdenum was very low compared to other trace elements. The content of zinc and boron was relatively close to each other. A high content of manganese was observed both in soil and in soil-forming rocks. But it should be noted that in soil-forming rocks the content of gross manganese is almost 2.5-3 times less than in soil, which is due to the properties of eluvial, rocky soil-forming rocks.
Trace elements Cu, Zn, Mn, Mo, B are vital for cotton, wheat plants and they cannot be replaced by other elements and play a specific biogeochemical role. The need for cotton and other crops of the cotton complex in these trace elements has been proven by Kruglova, Aliyeva [8], Sattarov, Yagodin, and others [6; 3]. In the conditions studied by us, the soil factor contributing to the deficiency in the migration of trace elements can be attributed to carbonate content (6-10%), gypsum in the zone, low humus content and the formation of barriers on the transitional-carbonate-illuvial horizon.
But it should be remembered that the main source of trace elements for crops in the irrigated area is soil. Despite the fact that in agronomic practice, mobile forms of microelements are important, in geochemical studies, their gross forms in the soil play an important role.
Copper accumulation in the upper horizons, a characteristic feature of the distribution of copper in the soil profile. This phenomenon is primarily associated with the results of the influence of various soil-geochemical factors.
Basically, the concentration of copper in the top layer of soil reflects its bioaccumulation at the sorption and humus barrier, as well as modern anthropogenic influence. In the soil of the serozem belt studied by us, the copper content in the soil horizons, with the rare exception of subsurface horizons, where copper is less than 22 mg/kg, is contained within 24.829.1 mg/kg, which gives basement to classify the serozems of southern Fergana secured by copper. According to above mentioned, we can conclude that the foothill landscapes according to the classification of Kruglova and Aliyeva belong to the provinces of sufficient copper content in the soil. Irrigated dark, typical, light gray soil on the content of gross copper are geochemical enrichment provinces.
The average zinc content in the surface layers of soil dark and typical gray makes up 121.2-131.3 mg/kg, in light gray soil 73.1 mg/kg, and in arable horizons in soil-forming rocks of gray soil 43.1-48.4 mg/kg. According to this indicator, irrigated dark and typical serozem, where the zinc content is more than 100 mg/kg belong to the group of soil with excessive content.
The soil of the serozem series, that is, the dark serozem contain manganese more than 600-800 mg/kg, it contains up to 900 mg/kg, whereas in the arable horizons of typical and light serozem it contains 685.4-708.3 mg/kg In the underlying horizons, manganese is contained not less than in arable horizons. Even in some horizons it is observed more than in arable depths.
The content of molybdenum in the soil was close to their concentration in parent rocks and varies in the intervals of 2.5-3.1 mg/kg. In the arable horizons it contains 3-3.5 mg/kg, approximately the same pattern is repeated in the subsoil horizons. In this case, the soil of the serozem belt can be attributed to the provision of molybdenum to the normally secured (>1-3 mg/kg).
In the earth's crust and in soil, boron is distributed non-uniformly. It concentrates mainly in the surface soil horizons. Its content in the arable horizons of the studied soil of the serozem series varies in the intervals of73-97 mg/kg, whereas in the subsoil horizons it contains 75-81 mg/kg. From the data it is clear that there is no deficit in boron, but an excess. The soil of the gray earth belt can be attributed to the geochemical enrichment provinces in terms of boron content.
Below are the rows of Clarke concentrations (CC) and Clarke scattering (Cp) of elements in these soil (table). It can be seen from the above materials that the CC of boron in the arable horizons of the studied soil varies from 6.1-8.1 with a higher concentration corresponding to irrigated dark serozem, which is associated with the genetic characteristics of dark serozem. In the remaining soil of the serozem range, the content takes intermediate situation.
Clark series of trace element concentrations in soil (upper horizon)
Name soil Gross Movable
Irrigated dark sero-zems B Mo Zn Mn Cu 8.09 > 3.2 > 1.58 > 0.9 > 0.63 Mo B Cu Mn Zn > > > > 0.32 0.18 0.07 0.03 0.02
Irrigated typical serozems B Mo Zn Mn Cu 6.86 > 3.18 > 1.46 > 0.71 > 0.53 Mo B Cu Mn Zn 0.25 > 0.17 > 0.09 > 0.05 > 0.02
Irrigated light sero-zems B Mo Zn Mn Cu 6.09 > 2.74 > 0.88 > 0.69 > 0.45 Mo Mn Cu B,Zn 0.22 > 0.17 > 0.04 > 0.02
CC of gross boron in serozems in southern Fergana in the humus horizon varies within 6.09-8.09, that this position is related to a higher content of humus. The size of the boron from top to bottom in the profile and in the verticality of the serozems gradually decreases to 4.83 in the parent rock. As expected, after boron, the second place is occupied by molybdenum CC with a CC of 3.2-2.7. In general, in the arable layers of serozem by CC, the studied elements occupy the following row: boron > molybdenum > zinc > manganese > copper.
Conclusions. Taking into account the gradation of soil on the content of trace elements are available to plants and
their content in the soil of serozem, the following can be noted: according to the content: the mobile form of copper, these soil belong to the Il-group of normal and secured; zinc in the soil of serozem range, where it contains 0.95-1.94 which belong to the group of poorly secured and secured; mobile manganese serozem poorly endowed, the content of mobile manganese in dark serozems, where it contains 16-36 mg/kg; rolling boron soil are located on the border of increased secured and enriched (0.27-2.1 mg/kg); in molybdenum can be attributed to the group normally and highly secured.
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