@article {KNZ001067, title = {Carbon and nitrogen pools in a tallgrass prairie soil under elevated carbon dioxide}, journal = {Soil Science Society of America Journal}, volume = {68}, year = {2004}, pages = {148 -153}, abstract = {

Soil is a potential C sink and could offset rising atmospheric CO2 The capacity of soils to store and sequester C will depend on the rate of C inputs from plant productivity relative to C exports controlled by microbial decomposition. Our objective was to measure pools of soil C and N to assess the potential for C accrual and changes to N stocks as influenced by elevated atmospheric CO2 Treatments (three replications, randomized complete block design) were ambient CO2\—no chamber (NC), ambient CO2\—chamber (AC), and two times ambient CO2\—chamber (EC). Long-term (290 d) incubations (35\°C) were conducted to assess changes in the slow soil fractions of potentially mineralizable C (PMC) and potentially mineralizable N (PMN). Potentially mineralizable C was enhanced (P \< 0.1) by 19 and 24\% in EC relative to AC and NC soil at the 0- to 5- and 5- to 15-cm depths, respectively. Potentially mineralizable N was significantly greater by 14\% at the 0- to 5-cm depth in EC relative to AC, but decreased by 12\% in EC relative to NC (P \< 0.1). Measurements of PMC indicate that increases in total soil C under elevated CO2 in a previous study were a consequence of accrual into the slow pool. Relatively large amounts of new C deposited as a result of elevated CO2 (Cnew) remained in the soil after the 290-d incubation. In contrast to accumulation of C into the slow fraction, Cnew was integrated into a passive fraction of soil organic matter (SOM). Accumulation of N was also detected in the whole soil, which cannot be explained by current estimates of ecosystem N flux.

}, keywords = {LTER-KNZ}, doi = {10.2136/sssaj2004.1480}, author = {Williams, M.A. and C. W. Rice and Omay, A. and Owensby, C.} }