『Abstract
We found exceptionally high nitrate levels (up to 12,750 kg ha-1)
at shallow depths (≦1 m) in soils mantled by desert pavement,
a common land-surface feature in arid regions. nearby soils without
desert pavement had nitrate contents that were one to two orders
of magnitude lower. The soil conditions coincident with desert
pavement (i.e., stability, antiquity, and virtually no leaching)
favor the retention and accumulation of nitrate delivered by atmospheric
deposition or in situ fixation. The nitrate stored in soils under
desert pavement is a previously unrecognized pool of nitrogen
that has the potential to increase the global nitrogen inventory
for near-surface desert soils to five times previous estimates.
Its near-surface occurrence makes this labile nitrogen pool particularly
susceptible to mobilization by climate change or human disturbance,
risking contamination of surface and groundwaters.
Keywords: desert pavement; soil; nitrogen; nitrate』
Introduction
Methods
Results
Discussion
Desert pavement hydrology
Soil nitrate inventory
Sources of nitrate
Implications for ecosystems and environmental quality
Acknowledgments
References cited