Ecological condition of the soils of the southern territory of the Republic of Uzbekistan

. According to experts, an individual's diet has a more significant impact on their health, around 90%, compared to healthcare services, which only impact about 10%. Certain elements like iron, copper, zinc, molybdenum, and trace elements play a crucial role in the biological functions of plants, animals, and humans. The study was carried out through both field and laboratory experimentation, following methodological manuals such as “Methods for agrochemical analysis of soil and plants”, “Methods for agrophysical research” and “Methods of conducting field experiments”. It was found that the aquifer also had a low content of alkalinity (NSO 3 ) at 0.024%, chloride ions at 0.007%, and sulfate ions at 0.027%, indicating that it is a chloride-sulfate salinity type. The next layers showed a total amount of easily soluble salts in water ranging from 0.065-0.085%, with a total alkalinity of 0.024%, chloride ion content at 0.004%, and sulfate ion content ranging from 0.016-0.023%


Introduction
The health of the soil is crucial for enhancing food production and expanding export opportunities, improving the quality of food, safeguarding human health, and addressing the effects of pollution and climate change. Experts suggest that 90% of a person's health is influenced by their diet, while only 10% is impacted by healthcare services. Iron, copper, zinc, molybdenum, and trace elements are essential for the biological functions of plants, animals, and humans. However, excessive heavy metal exposure can lead to health issues as these compounds can accumulate in tissues and cause diseases [1][2][3].
Currently, insufficient information exists about the condition of soil biodiversity and health on a national or regional level, which hinders the development of appropriate policies and measures for environmental protection, human health, and the cultivation of organic and exportable products. This lack of information has negative consequences for the effectiveness of implemented activities and results in the wastage of significant amounts of funds.
To properly evaluate the risks associated with soil health and biodiversity, it is crucial to conduct a national-level assessment of soil health [3][4][5]. This will help in identifying appropriate policies and measures for the agro-industrial complex, including the adoption of innovative technologies that promote human health and the sustainable use of soil resources. Without such an assessment, it will be difficult to achieve the desired effectiveness in these areas [4][5][6][7].
Assessing and analyzing the ecological status of soil is critical in the situations described above. This involves creating soil-ecological maps using modern GIS technologies, examining the impact of harmful substances in the soil on crop development and product quality, and selecting appropriate crops based on soil health [8,9]. Additionally, practical studies must be carried out to identify suitable areas for growing organic products. These activities are essential and represent urgent tasks that need to be addressed in the present day.

Materials and methods
Research was conducted on the soil in the Surkhandarya region of the Southern part of the Republic of Uzbekistan [4][5]. The study was carried out through both field and laboratory experimentation, following methodological manuals such as "Methods for agrochemical analysis of soil and plants", "Methods for agrophysical research" and "Methods of conducting field experiments". Furthermore, various methods were used to analyze different soil components, such as the Turin method for humus, the Keldal method for nitrogen, the Ginzburg method for general phosphorus, the Smitt method for potassium, and the Machigin method for phosphorus, while the ionoselective method was used to measure nitrate nitrogen in mobile forms, and the Nessler reagent was used to detect ammonium nitrogen [10]. The flame photometric chromatography method was used to measure potassium, and heavy metals were detected using the atomic absorption method with AAS lamp in the device [5][6][7].
Geoinformation system technologies were used to create digital maps of different areas based on Soil Quality Index (SQI) indicators. The maps were developed using interpolation techniques to assess the soil condition, ecological condition, and overall soil-ecological condition of each area. The analysis found that producing digital soil-ecological maps using geoinformation system technologies is both convenient and fast ( Fig. 1-3).

Results and Discussion
The table data shows that the upper plowed layers of soil in the surveyed section have a medium-coarse mechanical composition, comprising 37% physical clay particles (<0.01 mm) and extending to a depth of 0-34 cm. The subsequent subsoil layer has a medium clay composition and a lower physical clay content of 32.9. The third layer of soil has a light mechanical composition and an even lower physical clay content of 27.4 (Table 1).   The humus content in the arable layer of Surkhandarya region's soils is 0.393%, which indicates low supply based on Table 2. This content decreases to 0.378% in the subsurface layer and even further to 0.324% in subsequent lower layers, categorizing them as very low and low supply groups. The total nitrogen content in the region is 0.028%, with the maximum being 0.032%. The arable layer has a total potassium content of 0.41%, indicating a low supply, with values ranging from 0.33-0.27 in different layers. The total phosphorus content in the arable layer of soils is not high at 1.368%, and it decreases in subsequent layers, reaching 1.104% in the lowest layer according to Table 2. The Surkhandarya region has soils that are richly supplied with mobile phosphorus, with the highest amount found in the top layer at 49.6 mg/kg. As you move down to the subsequent layers, the amount of mobile phosphorus decreases and falls into the categories of medium, low, and very low supply, with levels ranging from 10.24 to 11.2 mg/kg. These results are shown in Table 2.
It was found that these soils were divided into very low (0-100 mg/kg) and low (100-200 mg/kg) supplied groups according to the amount of potassium that plants can absorb. Besides, the amount of exchangeable potassium in the arable layer of these soils was 180 mg/kg and decreases to the next layers. The amount of exchangeable potassium in the lowest layer was 79 mg/kg ( Table 2).
The soil analysis of the Surkhandarya region in Uzbekistan revealed that it is primarily composed of low salinity types, with a total amount of water-soluble salts in the soil profile at 0.069%. The aquifer also had a low content of alkalinity (NSO3) at 0.024%, chloride ions at 0.007%, and sulfate ions at 0.027%, indicating that it is a chloride-sulfate salinity type. The next layers showed a total amount of easily soluble salts in water ranging from 0.065-0.085%, with a total alkalinity of 0.024%, chloride ion content at 0.004%, and sulfate ion content ranging from 0.016-0.023% (Table 3). The study of soil samples from the Surkhandarya region in Uzbekistan revealed the amount of beryllium present in different soil types. The Tilling layer of the soil contained 2.04 mg/kg of beryllium, while soil samples from areas with different crops contained 1.90-2.40 mg/kg. The permissible amount of beryllium was not exceeded in any of the soil samples.
The amount of vanadium in the plowed layer of the soil in the Surkhandarya region was found to be 91.8 mg/kg. Soil samples were also collected from areas where different types of crops were grown, including cotton and potatoes. The amount of vanadium in these samples was higher than in the tilling layer, with values of 120 mg/kg for cotton fields and 100 mg/kg for potato fields. These levels exceed the permissible limit for vanadium in the soil, which indicates a potential environmental concern in these areas.
The concentration of Chromium element was measured in soil samples collected from different areas of Surkhandarya region of Uzbekistan. The results indicated that in the tilling soil layer, Chromium was present at a concentration of 74.7 mg/kg. In the areas where other crops were planted, the concentration of Chromium increased to 87.0 mg/kg, while in cotton and potato fields, it was found to be 91.0 mg/kg and 76.0 mg/kg, respectively. It was observed that the levels of Chromium element were up to three times higher than the permissible limit in the soils distributed in these areas.
The study analyzed the amount of manganese and cobalt elements in soil samples taken from different areas of crops in the Surkhandarya region of Uzbekistan. The results showed that the Tilling layer of soil had 773 mg/kg of manganese and 13.9 mg/kg of cobalt. Soil samples from cotton and potato fields had lower levels of manganese than the Tilling layer, but were still within the permissible limit. However, the cobalt levels in the soil samples were up to 3 times higher than the permissible amount. Similarly, in soil samples taken from areas planted with perennial trees and grain, cobalt levels were found to be higher than the permissible amount.
The tilling layer of soil in the studied area had 1.16 mg/kg of antimony element. Soil samples were taken from areas where different crops were grown, and antimony was found to be within permissible limits in all samples. The lead element in the Tilling layer of soil was 26.4 mg/kg. Soil samples were taken from areas where various crops were planted, and the levels of lead were found to be 3-5 times higher than the permissible amount in all soil samples, with the highest concentration found in the cotton fields.
The tilling layer of soil had 1.16 mg/kg of antimony, and soil samples were taken from areas with other crops which showed 1.00 mg/kg in the soil sample taken from perennial gardens, 0.960 mg/kg from cotton fields, and 1.10 mg/kg from potato fields. The antimony levels in the distributed soil samples were within the permissible amount. In the same soil layer, lead was detected at 26.4 mg/kg and soil samples were taken from areas with different crops which showed 24.0 mg/kg, 23.0 mg/kg in cotton fields, and 22.0 mg/kg in potato fields. The lead element in these soil samples was 3-5 times higher than the permissible amount.
The concentration of cadmium in the tilling layer of soil is 0.360 mg/kg, and soil samples were collected from fields planted with various crops, including perennial trees, grains, cotton, and potatoes. The concentration of cadmium in these samples was within permissible limits. On the other hand, the concentration of nickel in the driving soil layer was 53.9 mg/kg, and soil samples were taken from fields planted with different crops, including perennial trees, grains, cotton, and potatoes. The concentration of nickel in these samples was found to be three times higher than the permissible limit of 25.0 mg/kg. The concentration of zinc in the soil layer is 86.5 mg/kg, and soil samples were collected from fields planted with different crops, including perennial trees, grains, cotton, and potatoes. The concentration of zinc in these samples was found to be higher than the permissible limit in the cotton and grain planted areas. The zinc concentration was 83.0 mg/kg in the soil sample from the field planted with perennial trees, 100.0 mg/kg in the soil sample from the grain field, 84.0 mg/kg in the soil sample from cotton fields, and 86.0 mg/kg in the soil sample from potato fields.
The concentration of copper in the soil layer was 44.8 mg/kg, and soil samples were collected from fields planted with various crops, including cotton and potatoes. The concentration of copper in these samples was within the permissible limit of 100 mg/kg. In contrast, the concentration of selenium in the tilling layer of soils was 2.23 mg/kg, and soil samples were taken from fields planted with various crops, including perennial trees, grains, cotton, and potatoes. The concentration of selenium in these samples did not exceed the permissible limit.
The soil samples were collected from areas planted with various crops, including cotton, potatoes, vineyards, grains, and perennial trees. The concentration of margumush element in the Tilling soil layer was found to be 19.1 mg/kg, which exceeded the permissible limit of 2 mg/kg in all soil samples. The highest level of margumush element pollution was observed in the vineyard area, up to 14 times higher than the limit. Similarly, the concentration of tin element in the tilling soil layer was 3.17 mg/kg, and it was within the permissible limit in all soil samples collected from the areas planted with different crops, including cotton, potatoes, grains, and perennial trees.
The text describes the evaluation of soil quality indicators (SQI) based on soil productivity and heavy metal contamination. The soil evaluation scores were determined for different regions based on these indicators and their ecological status was also evaluated. The overall soil-ecological status scores were then calculated based on both assessment criteria. The results showed that while the soil condition of all regions was relatively high, their ecological condition was low. In particular, the Surkhandarya region in Uzbekistan had highly productive soils with low ecological status. The overall SQI scores for these soils were lower than average, indicating lower quality levels. Similarly, the overall average score for the soils in the main sections was also below average, indicating lower quality levels.
The text outlines a study in which soil quality indicators (SQI) were evaluated for the Surkhandarya region of Uzbekistan, based on assessments of soil productivity indicators and heavy metal contamination. The evaluation process involved determining the soil evaluation scores for productivity indicators and ecological status, and then calculating the overall soil-ecological status scores based on both assessment criteria. Results showed that, while the soil condition scores were relatively high across all regions, ecological condition scores were low. Specifically, the base cross-section from Surkhandarya had a high score of 63 points based on soil properties, but a low score of 40 points based on ecological condition, indicating a low ecological status for highly productive soils. The overall SQI score for this section was 46, indicating a lower than average quality level. Further analyses revealed that the soil properties scores for the main sections ranged from 71 to 52 points, with an average of 61 points. Ecological condition scores were slightly lower, ranging from 46 to 42, with an average of 44. Overall, the SQI scores for these soils were in the range of 50-45 points, indicating below average quality levels. The overall average score for these soils was 47 points, indicating a lower than average quality level (Table 4). Using geoinformation system technologies, digital maps of the studied arrays evaluated based on SQI indicators were developed. Interpolation methods of geo-information system technologies were used to develop soil condition assessment map for each array, soil ecological condition assessment map and general soil-ecological assessment maps. According to the results of the analysis, the convenience and speed of production of digital soil-ecological maps using geoinformation system technologies was noted.

Conclusions
Surkhandarya region of the Republic of Uzbekistan in the arable layer of soils in the region, it forms a group that is poorly supplied with humus, very high with mobile phosphorus and poorly supplied with exchangeable potassium. The upper arable (0-34 cm) layers of the soil consist of medium sand mechanical composition.
According to the degree of contamination with chemical elements in the soil distributed in the southern regions of our republic, Cd, V elements have doubled and Cr, Ni, Pb, Co elements have increased three times over the allowed amount, and the highest soil polluting chemical elements are molybdenum 4 times and manganese 14 times higher than the allowed amount. . This indicates the rapid pollution of the environment with toxic elements along with the increase in the production scale of industrial enterprises.
Surkhandarya region of the Republic of Uzbekistan is 47 points and belongs to the lower than average quality level.