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Rainfall limit of the N cycle on Earth

Global Biogeochemical Cycles

By:
, , , , , , , , ,
DOI: 10.1029/2006GB002838

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Abstract

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- (??17O = 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. Copyright 2007 by the American Geophysical Union.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Rainfall limit of the N cycle on Earth
Series title:
Global Biogeochemical Cycles
DOI:
10.1029/2006GB002838
Volume
21
Issue:
3
Year Published:
2007
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Global Biogeochemical Cycles