Organic carbon organic matter and bulk density relationships in arid-semi arid soils in Southeast Anatolia region

Soil organic matter (SOM) and soil organic carbon (SOC) constitute usually a small portion of soil, but they are one of the most important components of ecosystems. Bulk density (dB or BD) value is necessary to convert organic carbon (OC) content per unit area. Relationships between SOM, SOC and BD were established in weak alkaline clay fractions of agriculture soils in Southeast Anatolia Region in Turkey. The importance of such relationships results from using sample and rapid techniques to estimate SOC-BD and SOM-BD relationships. Between SOM and SOC, the positive strongest relationship for three models (R 2 =0.9976; 0.9982; 94.64) were detected. For SOM-BD and SOC-BD, negative relationship for three models were determined (R 2 =0.1342; 0.1420; 0.1329 and R 2 =0.1266; 0.1252; 0.1378 respectively). The mismanagement and land cultivation in the past and present causes soil degradation. Therefore, the soil organic matter and carbon are now below their potential level. Evaluation of their stocks requires knowledge about BD. BD is affected by factors such as water, aeration status, root penetrate, clay content, texture, land use and management, therefore it is a very important soil parameter.