Maize root-induced change in soil organic carbon pools
2002
Liang, B.C. | Wang, X.L. | Ma, B.L.
Quantification of root or root-induced changes in soil organic C (SOC), water-soluble organic C (WSOC), and microbial biomass C (MBC) is important for understanding processes of soil C storage. A greenhouse study was conducted on a Bainsville loamy sand (Typic Hapludoll) to evaluate root or root-induced quantitative and compositional changes in various SOC pools by growing corn (Zea mays L.), a C4 plant, on a historically C3 soil. Significant shifts in 13C of SOC pools, most noticeably in WSOC and MBC were observed. During the course of a growing season, the proportion of C4-derived C varied from 0 to 12.3% of whole SOC, from 0 to 30.7% of WSOC, and from 0 to 52% of MBC, indicating a major contribution of root or root-induced C to various soil C components, especially WSOC and MBC. The amount of C4-derived C in the entire soil estimated by the 13C natural abundance (delta13C) was remarkably consistent with the amount of C4-C retained in the soil microbial biomass, WSOC, and corn roots, suggesting that measurements of 13C of the entire soil following the shift of C3 to C4 plants can be used as an indirect measure of root or root-induced C pools during the growing period.
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