Determination of organic matter content in arid-zone soils using a simple “loss-on-ignition” method

A simple and rapid procedure for the determination of organic matter content in mineral soils by loss-on-ignition without pretreatment was studied. Attention was given to the possible effect of inorganic compounds abundant in mineral soils on the estimation of organic matter content by this method. Both fast heating (DTA-TGA type) studies and prolonged heating procedures were employed on natural and synthetic' soils. The results were compared to those obtained by the dichromate wet-oxidation method widely used in soil laboratories for organic matter determination. In a group of 91 soils collected from various mineral soils in Israel, and having OM contents between 0.09 and 13.23%, a correlation coefficient of 0.972 was obtained for the linear regression between organic matter content measured by the proposed method and organic carbon measured by the dichromate wet-oxidation method.