Determination of Spatial Changes in Basic Characteristics and Nutrients of Soil Using Geographic Information Systems

Türkçe

Soil, along with air and water, is one of life's three indispensable components and has been counted among the five basic elements since ancient times. A single physical or chemical property of soil is insufficient to determine soil quality; assessing a combination of these properties provides more reliable and comprehensive insights into soil quality characteristics. Choosing soil sampling points representative of the region's overall structure enhances the accuracy of quality assessments. This study, conducted in Yozgat province in the Central Anatolia region, aims to generate topographic and essential nutrient element maps using a Geographic Information System (GIS) technique based on analyses of soil samples collected from 30 different wild rosehip cultivation areas. Maps were created for texture, total calcium carbonate (CaCO3), pH, electrical conductivity (EC), macronutrients (N, P, K, Ca, and Mg), micronutrients (Fe, Mn, Zn, and Cu), exchangeable sodium (Na), and the Universal Soil Loss Equation's soil erosion factor (USLE-K). Initially, slope, aspect, elevation, and relief maps were generated using a digital elevation model obtained from ASTER DEM (GDEM). Results indicate that areas up to 1500 m above sea level comprise 89.32% of the province's total area. Areas with a 0-5º slope represent 50.74% of the total area. South, west, and east-facing aspects prevail in the province. The three most extensive land use/cover categories are non-irrigated arable land (35.294%), continuously irrigated land (14.212%), and agricultural areas with natural vegetation (10.458%), respectively. Areas with EC values below 750 µmhos cm-1 constitute 45.47% of the total area. Analysis revealed that 16.61% of the province is moderately calcareous, 39.47% is calcareous, and 37.05% is highly calcareous. The lowest pH value was recorded in the Aydıncık district.