Opportunities and threats of deep soil organic matter storage

摘要

Since the industrial revolution, exploitation of natural resources through energy generation and agricultural activity has led to increasing atmospheric concentrations of GHGs with dramatic effects on the Earth's climate system. More than a decade after the Kyoto Protocol, it has become evident that a worldwide reduction of GHG emissions is impossible with the technologies currently available; therefore, carbon management in natural systems has gained increasing attention, especially restoration of carbon lost from the biosphere in particular from soils . Soil organic matter (SOM) storage may therefore be the key to counteract rising atmospheric GHG concentrations . As such, soil carbon storage has received enormous attention in recent years. Soil, with 1550 Pg (1 Pg = 10~(15) g) to 2000 Pg , is the largest active carbon reservoir in the global of the terrestrial biosphere. This makes it susceptible to respond to management practices. Soil carbon storage estimates have taken into consideration the upper first meter of soil; however, if deeper layers were taken into account, the amount of carbon stored in soil is likely to be higher. More than 50% of the total carbon stocks in the profile are usually recorded in subsoil horizons. This editorial therefore considers the opportunities and threats of such deep soil organic matter storage.