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Soils, a sink for N 2 O? A review
Author(s) -
CHAPUISLARDY LYDIE,
WRAGE NICOLE,
METAY AURÉLIE,
CHOTTE JEANLUC,
BERNOUX MARTIAL
Publication year - 2007
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/j.1365-2486.2006.01280.x
Subject(s) - nitrous oxide , soil water , denitrification , sink (geography) , environmental science , temperate climate , greenhouse gas , nitrogen , environmental chemistry , agronomy , soil science , chemistry , ecology , geography , cartography , organic chemistry , biology
Soils are the main sources of the greenhouse gas nitrous oxide (N 2 O). The N 2 O emission at the soil surface is the result of production and consumption processes. So far, research has concentrated on net N 2 O production. However, in the literature, there are numerous reports of net negative fluxes of N 2 O, (i.e. fluxes from the atmosphere to the soil). Such fluxes are frequent and substantial and cannot simply be dismissed as experimental noise. Net N 2 O consumption has been measured under various conditions from the tropics to temperate areas, in natural and agricultural systems. Low mineral N and large moisture contents have sometimes been found to favour N 2 O consumption. This fits in with denitrification as the responsible process, reducing N 2 O to N 2 . However, it has also been reported that nitrifiers consume N 2 O in nitrifier denitrification. A contribution of various processes could explain the wide range of conditions found to allow N 2 O consumption, ranging from low to high temperatures, wet to dry soils, and fertilized to unfertilized plots. Generally, conditions interfering with N 2 O diffusion in the soil seem to enhance N 2 O consumption. However, the factors regulating N 2 O consumption are not yet well understood and merit further study. Frequent literature reports of net N 2 O consumption suggest that a soil sink could help account for the current imbalance in estimated global budgets of N 2 O. Therefore, a systematic investigation into N 2 O consumption is necessary. This should concentrate on the organisms, reactions, and environmental factors involved.