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Bobomurodov Shuxrat Mehribonovich, PhD., Senior researcher, Research Institute of Soil Science and Agrochemistry, E-mail: shuhrat_bm@inbox.ru Baxodirov Zafar Abduvalievich, Researcher,
Research Institute of Soil Science and Agrochemistry, E-mail: zafarbahodirov@gmail.com
APPLICATION OF GEOINFORMATION SYSTEM TECHNOLOGIES IN STUDYING SOIL PROPERTIES
Abstract: The article describes application of geographic information systems for soil properties studying. According to the results, using GIS technologies in soil studies is easy and optimistic way to analyze soil properties. Therefore, application of GIS systems will improve land resources management, land use planning, soil fertility improvement and soil protection.
Keywords: soil, land resources, soil properties, soil fertility, geographic information system, soil map, digital soil mapping, spatial interpolation.
Introduction
Obtaining reliable information on agricultural lands, efficient and rational use of them, predetermining negative anthropogenic factors require the development of measures based on scientific research. To do this, the use of new methods in soil mapping, especially, when integrated soil research is limited, the use
of new geo-information technologies will bring the industry to a new level and will achieve high productivity. In addition, the use of these technologies will shorten the time required for the initial (preliminary) and final (cameral) stages of soil mapping, the speed of work, the upgrade and processing capabilities of the database will increase.
Figure 1. Map of the research object's location
In our republic, too, the application of geoinforma-tion systems in agriculture promotes effective and rational management of land resources. This technology links geographic information with data from traditional soil mapping works. The use of geographic information in this field creates abilities on the basis of modern computer programs and devices analyzing the entire range of information about a specific subject or object and solving problems in a certain area, as well as developing a geoin-formation system of soil fertility and soil fertility models, predicting the adverse effects of negative factors on soils.
The research objects and methods
As of the object of the research was chosen Yangio-bod in Mirzaobod district of Syrdarya region.
The methods of research was based on commonly accepted methods, comparative-geographical, laboratory-analytical, statistical analysis of data and geospatial analysis based on geographical information systems, mathematical processing of data.
Initially field-soil research was carried out on the sites of this research object. In the field, primary and secondary soil sites were laid, soil samples were taken for chemical analysis. During the soil survey, the coordinates of each soil site were determined by using GPS devices to determine the geographical location of the soil samples.
For creating soil fertility maps based on geo information systems several indicators (humus, gypsum,
CO2, N-NO3, P2O5, K2O, dry residue, NCO3, Cl and SO4 compounds) were selected. These indicators were selected based on their role in determining the basic properties of the soils and geoinformational analysis was carried out using the Geostatistical Analyst (GA) module of ArcGIS. The coordinates of the geographical location of the main soil sites were determined and the values of the chemical results of the soil samples were entered. The spatial distribution of soil properties on the experimental field has been determined. For this purpose, methods of interpolation in the Geostatistical Analyst (GA) module of ArcGIS were used.
The research results
Humus and nutritional status of soils
The productivity and fertility of irrigated soils depends largely on the availability of humus and nutritional content. The role of humus in the formation of processes, changes and properties in the soil is very important. Organic matter in the soil is capable of collecting and maintaining a large amount of nutrients and moisture due to the excessive absorbency and capacity of water.
The humus content in topsoil of the studied irrigated soils is within range of 0.57% to 1.20%. P2O5 (phosphorus) substances have a mean range of 2.67 mg/kg to 31.20 mg/kg. K2O (potassium) substances in the topsoil of the studied soils varies from 20 mg/kg to 268 mg/kg.
Figure 2. Map of humus distribution on irrigated soils of Yangiobod in Mirzabad district of Syrdarya region
Soil salinity, types and degree of soil salinity Salinity is one of the main soil processes determining the fertility and ecological and reclamation status of irrigated lands, which depends on relief, geomorphologic-lithological structure, hydrogeological and human-economic conditions of the region, technical condition of hydromeliorative systems and a number of other factors.
According to the results of the research, the irrigated soils of Yangiobod in Mirzaabad district of Syrdarya re-
gion are mostly medium, strong and very strong saline, with a total amount of water-soluble salts in the soil profile forming a wide range of 0.275-4.895%. The amount of HCO3 content is 0.021-0.043%, the content of chlorine ion is 0.021-0.843% and the sulfate ion fluctuates at 0.117-2.402%. According to salinity chemistry, the main soil sites consist of chloride-sulfate and sulphate saline types.
Figure 3. Salinity (sulfur) map of irrigated soils of Yangiobod in Mirzabad
district of Syrdarya region
The general evaluation map of the soil
Figure 4. General evaluation map of irrigated soils of Yangiobod of Mirzabad district of Syrdarya region
After determining key characteristics of the soil on the experimental area, according to the aforementioned indicators, at the next stage interconnected spatial analysis was performed by using several indicators, ie, the interaction of soil properties in the determination of soil fertility was studied using geostatistical analysis in ArcGIS software. Geostatistical Analyst's model gave opportunity to determine the fertility of the soil, to select the specific indicators that characterizes their fertility and to determine the bonitet score of the experimental site.
Conclusion
As a result of the research, it was found that ArcGIS software modules Spatial Analyst and Geostatistical Analyst will provide broader opportunities for researchers to analyze the results of soil research and to create special thematic maps. In addition, geographic information system used for conducting soil surveys showed great
opportunities to analyze the data provided by multiple methods simultaneously, to monitor soil status based on the data collected over the years, to make the data available to consumers at any size and in the electronic copy, also many other similar options.
Also, maps derived from GIS technologies provide accurate and up-to-date information on the soil condition of the area, its fertility level. This, in turn, provides an opportunity to determine the availability of land resources for agriculture, to monitor land degradation, to plan agricultural lands, to analyze soil conservation measures.
In conclusion, it should be noted that the use of modern geoinformation technologies in the field of soil science can provide accurate and timely information, increase possibilities for their operational processing and storage, as well as a database of soil properties will be created, resulting in a creating possibility to thorough analysis of the condition of land resources.
References:
1. Mc Bratney and Lagacherie, Global Workshop on Digital Soil Mapping, Montpellier, - 2004.
2. Atkinson P. M. 1999. Geographical information science: geo statistics and uncertainty. Progress in Physical Geography, - 2007.
3. Colin Childs, Gary Kabot, "Working witch ArcGIS Spatial Analyst", ESRI, - 2006.
4. "Computerized Systems of Land Resources Appraisal for Agricultural Development", World Soil Resources Report, Rome, - 2003.
5. Guide "Using ArcGIS Desktop", ESRI Press, - 2006.
