Assessment and mapping of soil fertility in Central Anatolian croplands

The purpose of this study was to determine the current status of soil nutrient content, creating an actual soil nutrient database and mapping of agricultural lands in Central Anatolian using Geographical Information Systems (GIS). Soil samples were taken from 0-30 cm depth and the coordinates of the sampling points were recorded. In 2672 soil samples taken, soil texture, pH, total soil salinity, calcium carbonate, organic matter, available micro and macro elements were analyzed. Analysis results of these samples were classified and evaluated for deficiency, sufficiency or excess in respect of plant nutrients. Then, a database of the study area was created by using GIS techniques and soil fertility maps were produced. According to the results, 75.9% of the region is composed of clay loam and loamy soils. 89.2% of the region is composed of slightly alkaline and 99.4% is composed of non salty soils. In terms of organic matter, 85.5% of the region is low and very low. 56.1% of the region is high and very high calcareous. In terms of the available phosphorus content, 75.4% of the region is moderate, low and very low class. In terms of available potassium content, 94.4% of the region is in excess. 99.2% of the exchangeable calcium content and 93.4% of the exchangeable magnesium content of the region is sufficient, high and very high. Respectively, 44.8%, 75.3% and 92.3% of the available iron, zinc and manganese contents of the region are classified as low and very low. 98.8% of the region is sufficient in terms of the available copper