TY - JOUR
T1 - Rainfall limit of the N cycle on Earth
AU - Ewing, Stephanie A.
AU - Michalski, Greg
AU - Thiemens, Mark
AU - Quinn, Richard C.
AU - Macalady, Jennifer L.
AU - Kohl, Steven
AU - Wankel, Scott D.
AU - Kendall, Carol
AU - Mckay, Christopher P.
AU - Amundson, Ronald
PY - 2007/9
Y1 - 2007/9
N2 - In most climates on Earth, biological processes control soil N. In the Atacama Desert of Chile, aridity severely limits biology, and soils accumulate atmospheric NO3-. We examined this apparent transformation of the soil N cycle using a series of ancient Atacama Desert soils (>2 My) that vary in rainfall (21 to <2 mm yr-1). With decreasing rainfall, soil organic C decreases to 0.3 kg C m-2 and biological activity becomes minimal, while soil NO3- and organic N increase to 4 kg N m-2 and 1.4 kg N m-2, respectively. Atmospheric NO3- (Δ17O = 23.0‰) increases from 39% to 80% of total soil NO3- as rainfall decreases. These soils capture the transition from a steady state, biologically mediated soil N cycle to a dominantly abiotic, transient state of slowly accumulating atmospheric N. This transition suggests that oxidized soil N may be present in an even more and and abiotic environment: Mars.
AB - In most climates on Earth, biological processes control soil N. In the Atacama Desert of Chile, aridity severely limits biology, and soils accumulate atmospheric NO3-. We examined this apparent transformation of the soil N cycle using a series of ancient Atacama Desert soils (>2 My) that vary in rainfall (21 to <2 mm yr-1). With decreasing rainfall, soil organic C decreases to 0.3 kg C m-2 and biological activity becomes minimal, while soil NO3- and organic N increase to 4 kg N m-2 and 1.4 kg N m-2, respectively. Atmospheric NO3- (Δ17O = 23.0‰) increases from 39% to 80% of total soil NO3- as rainfall decreases. These soils capture the transition from a steady state, biologically mediated soil N cycle to a dominantly abiotic, transient state of slowly accumulating atmospheric N. This transition suggests that oxidized soil N may be present in an even more and and abiotic environment: Mars.
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U2 - 10.1029/2006GB002838
DO - 10.1029/2006GB002838
M3 - Article
AN - SCOPUS:36749070879
SN - 0886-6236
VL - 21
JO - Global Biogeochemical Cycles
JF - Global Biogeochemical Cycles
IS - 3
M1 - GB3009
ER -