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Nitrate Reduction in Spartina Alterniflora Marsh Soil
Author(s) -
Smith C. J.,
DeLaune R. D.,
Patrick W. H.
Publication year - 1982
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1982.03615995004600040016x
Subject(s) - salt marsh , anoxic waters , spartina alterniflora , nitrate , soil water , environmental chemistry , chemistry , sediment , marsh , environmental science , denitrification , salt (chemistry) , hydrology (agriculture) , nitrogen , soil science , ecology , wetland , geology , biology , geomorphology , geotechnical engineering , organic chemistry
The transformation of nitrate (NO ‐ 3 ) was investigated in flooded Louisiana Gulf Coast salt marsh soll. Nitrate formed in the aerobic zone of the soil is readily reduced in the deeper anoxic zone by dissimilatory and/or assimilatory processes. The experiments were conducted in soil cores 15 cm in diameter by 12 to 15 cm in depth. 15 N‐labelled NO ‐ 3 at 0.6 g N m −2 was administered in either a single injection into the floodwater or in repeated small injections below the sediment‐water interface. For the single application experiment, 14% of the 15 N remained in the system; 4% NH + 4 ‐N and 10% organic N. This implies dissimilatory reduction, with NO ‐ 3 being reduced to NH + 4 prior to formation of organic N. Fifty separate applications increased the recovery of 15 N in the NH + 4 ‐N and organic N pool to 52%. The latter procedure more nearly reproduces the low steady‐state concentration of NO ‐ 3 observed in salt marsh soil; the increased recovery suggests that the internal inorganic‐N cycling in these soils may be more efficient than previously reported.