Nondestructive system for analyzing carbon in the soil
Carbon is an essential component of life and, in its organic form, plays a pivotal role in the soil’s fertility, productivity, and water retention. It is an integral part of the atmospheric–terrestrial C exchange cycle mediated via photosynthesis; furthermore, it emerged recently as a new trading commodity, i.e., “carbon credits.” When carefully manipulated, C sequestration by the soil could balance and mitigate anthropogenic CO2 emissions into the atmosphere that are believed to contribute to global warming. The pressing need for assessing the soil’s C stocks at local, regional, and global scales, now in the forefront of much research, is considerably hindered by the problems besetting dry-combustion chemical analyses, even with state-of-the-art procedures. To overcome these issues, we developed a new method based on gamma-ray spectroscopy induced by inelastic neutron scattering (INS). The INS method is an in situ, nondestructive, multielemental technique that can be used in stationary or continuous-scanning modes of operation. The results from data acquired from an investigated soil mass of a few hundred kilograms to an approximate depth of 30 cm are reported immediately. Our initial experiments have demonstrated the feasibility of our proposed approach; we obtained a linear response with C concentration and a detection limit between 0.5 and 1% C by weight.