Generally there is a measure using the ratio of concentration of Br and organic carbon in soils. So is it possible to consider organic matter content regardless of organic carbon.
Br has a significant positive correlation with exchangeable calcium and organic carbon, especially in calcareous soil. The Br content in soil varies from 5 to 40 mg kg-1
Sedimentary rocks contain relatively high concentration of Br commonly associated with detrital organic material. Organic matter accumulate Br, and a strong correlation of Br with organic C in soil has been reported by Kabata-Pendias, 2001. It has significant correlation with exchangeable Ca and organic C as Dr, Malhotra already mentioned. I suggest to go through the attached file .