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Fixation and Loss of Nitrogen During Transformations of Nitrite in Soils
Author(s) -
Smith C. J.,
Chalk P. M.
Publication year - 1980
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/sssaj1980.03615995004400020017x
Subject(s) - soil water , nitrite , chemistry , organic matter , nitrogen , decomposition , incubation , environmental chemistry , nitrogen fixation , alkali soil , nitrate , ecology , organic chemistry , biology , biochemistry
When alkaline‐hydrolyzing N fertilizers are band‐applied to soils, the biological oxidation of NO 2 ‐ is inhibited and NO 2 ‐ may accumulate. Nitrite can react chemically with soil organic matter and become fixed, and at the same time nitrogenous gases can be evolved. The aim of the work described here was to study mechanisms of gaseous‐N formation using 15 NO 2 ‐ as a tracer, and to define the relationship between fixation and loss of N. Fixation of Na 15 NO 2 in five soils varying in pH and organic C content ranged from 0.6 to 36% of applied NO 2 ‐ , while the 15 N not recovered varied from 6 to 53%. A significant positive correlation was found between 15 N fixed and 15 N not recovered in the five soils, sampled after 1, 2, and 3 days of incubation. The 15 N enrichment of NO + NO 2 evolved from three γ‐irradiated soils treated with Na 15 NO 2 was only slightly less than the atom % 15 N of added NO 2 ‐ , and the rate of evolution increased as the pH of the soils decreased. These data suggest that NO + NO 2 was derived from the self‐decomposition of HNO 2 . Approximately equal amounts of indigenous soil N and added NO 2 ‐ ‐N reacted to form N 2 , indicating that a Van Slyke‐type reaction may have been partly responsible. Differences in the atom % 15 N 2 between soils suggested that more than one loss mechanism was operating, and that their relative importance may have been determined by soil pH. Nitrogen‐15 balance data showed that another nitrogenous gas, in addition to N 2 O, was evolved.