Application of GIS technologies for monitoring lands of Zainsk state variety testing area of Republic of Tatarstan

The object of the monitoring is Zainsky variety-testing area located in the East Zakamye of the Republic of Tatarstan. To study the application of GIS technologies for monitoring nutrients data were collected from 1977 to 1987. The base for creating a digital soil map of the study area is the method of forming digital soil maps developed by the Department of Soil and Land Evaluation of the Southern Federal University. The methodology is the use of free software and remote sensing data available from open sources. The method of step by step studying of the soil science information technology courses block is described. The work was conducted in the environment of GIMP, Google Earth, XML Notepad, Soil_Countur, MS Access, ArcMap, ArcReader programs. On the basis of the programs we carried out preliminary editing of images, georeferencing images on the area, creating a list of qualifiers, vectorizing data, entering attribute data, editing of files. We also estimated the constructed digital terrain models using the methods of interpolation and geostatistics. Thematic batteries content cartograms built without application of interpolation methods for monitoring indicators of soil fertility in general may not be suitable because they are the least informative and carry the discrete values of soil properties. At the same time, these cartograms have the property of the statics of feature of the elementary sampling site. Construction of approximating interpolation surfaces according to data of different years using geostatistical approach proved sufficiently clear changes in the content of nutrients for the ten-year period of intensive agricultural use. Interpolation surfaces were constructed by the method of universal Kriging with the account of global trends. Given the global trends in the content of nutrient elements interpolation surfaces were constructed for each indicator of soil fertility. To analyze the effect of trends in the construction of interpolation models we compared models built with the presence of residual trends and models with remainders of trends. Most of the models with trends described the distribution of nutrients to the surface more correctly. In general, by 1987 the state of potash and phosphoric area worsened. By the content of easy hydrolyzable nitrogen the opposite is true: in 1977 its content was significantly higher compared to 1987. By pH values of the salt extract values are almost identical, in 1987 the reaction of arable soil horizons was weak acidic or close to neutral.

Keywords

Authors

References