Use of Geostatistics and Geographical Information Systems Techniques in the Management of Gökhöyük Agricultural Farm

Spatial variability of soil properties which vary greatly depending on land use, parent material and topography significantly affects soil fertility, quality, and overall sustainability. This study was carried out to determine and map the spatial variability of some of soil properties in Gökhöyük Agricultural Farm, which is approximately 1900 ha, and to identify the problems that may affect the sustainable use of the land and to propose solutions. For this purpose, soil samples representing the study area were collected from 63 points and 4 different depths (0-30, 30-60, 60-90 and 90-120) along with 19 water samples from 1.5-2.0 m depths. Electrical conductivity (EC), pH, clay, sand, silt contents and hydraulic conductivity values of soil samples, and pH and EC values of the groundwater samples were determined from 19 points. The general status and spatial variability of soil properties studied were characterized by classical statistics and geostatistical methods. According to the results of the study, the hydraulic conductivity values (<20 mm h-1) were found to be very low in both surface and subsoil soils having high clay content. The pH values, which have a significant effect on plant nutrient availability, were higher than 8.5 at all depths in a significant portion of the study area. The EC values of soils (60-120 cm depth) located in the middle part of the study area were high (>4 dS m-1), to be considered as problematic. The EC values of water samples in this location were above 20 dS m-1. Highly saline ground water that transported to the soil surface with capillarity in the dry and hot seasons can harm the productivity function of soils. Spatial distribution maps of the soil properties will enable to make the accurate decisions which will contribute to the development of plant production and improvement of soil quality in the farm land.