ISSN:
1432-0789
Keywords:
Volatile fatty acids
;
Water-soluble C
;
Nitrate
;
Nitrite
;
Fermentative nitrate reduction
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Nitrous oxide production (denitrification) during anaerobic incubation of ground-alfalfa-, red-clover-, wheat-straw-, and cornstover-amended soil was positively related to the initial water-soluble C content of the residue- amended soil. The water-soluble C concentration decreased in all treatments during the first 2 days, then increased in the alfalfa-, red-clover-, and wheat-straw-amended soil until the end of the experiment at 15 days. An accumulation of acetate, propionate, and butyrate was partly responsible for the increased water-soluble C concentration. Denitrification rates were much higher in the alfalfa-and red-clover-amended soil, but NO 3 − was not fully recovered as N2O in these treatments. Supported by earlier experiments in our laboratory, we conclude that some of the NO 3 − was reduced to NH 4 + through fermentative NO 3 − reduction, otherwise known as dissimilatory NO 3 − reduction to NH 4 + . Acetate, the primary product of anaerobic fermentation, accumulated in the alfalfa- and red-clover-amended soil in the presence of NO 3 − , supporting previous observations that the processes of denitrification and fermentation occur simultaneously in C-amended soil. The partitioning of NO 3 − between denitrification and fermentative NO 3 − reduction to NH 4 + depends on the activity of the denitrifying and fermentative bacterial populations. NO2 concentration may be a key in the partitioning of NO 3 − between these two processes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00257824
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