Microbial characteristics of soils from graves: an investigation at the interface of soil microbiology and forensic science

Abstract

Very little is known about the microbiology of graves. We have taken the opportunity to investigate this subject by taking advantage of the unusual opportunity afforded by the experimental burial of pigs in a forensic experiment. Selected microbial characteristics of soils from the 0–15 and 15–30 cm depths of the graves of three pigs and of control soils have been determined 430 days after burial. The grave soils contained more total C, microbial biomass C and total N, and showed increased rates of respiration and N mineralisation compared to the control soils. The grave soils also had larger amino acid and NH 4 + concentrations, which was consistent with the increases in both net N mineralisation and pH values. Nitrification was not detected in any of the soils and the limited NO 3 − supply restricted the rate of denitrification, but the large alkali-soluble S 2− concentration of soils from the graves indicated reducing conditions in the graves.