Contribution of soil organic carbon and C3 sugar to the total CO2 efflux using 13C abundance
R. Koçyiğithttps://doi.org/10.17221/3429-PSECitation:Koçyiğit R. (2006): Contribution of soil organic carbon and C3 sugar to the total CO2 efflux using 13C abundance. Plant Soil Environ., 52: 193-198.
The differences in C isotope ratio of C3 and C4 plant species have been used to determine relative contributions of carbon (C) sources to total CO2 efflux. The objective of this study was to estimate the contribution of soil organic C and C3 sugar to total CO2 of corn and wheat monocultures during a short-term incubation. Control soils and soils amended with sugar were incubated at 25°C for 48 hours and total CO2 concentration and δ13C values of evolved CO2 were measured. The proportional contribution of C sources on CO2 efflux was determined by using isotopic composition of soil organic C and C3 sugar. δ13C values of soils are highly affected by the type of vegetation and the soil management. The C3 sugar addition in soils double the CO2 efflux in the corn soil, but it did not affect CO2 efflux in the wheat soil. This indicated a larger turnover of microbial biomass in the corn soil. The greatest significant (P < 0.05) difference in δ13C values between the control and sugar added soils occurred at 12 hours in the corn soil (11.2‰) and at 24 hours in the wheat soil (9.4‰). The estimated relative contribution of sugar to CO2efflux was stronger at 12 hours incubation in the corn soil.Keywords:
13C natural abundance; soil organic carbon; sugar; CO2 source