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Soil Nitrogen and Carbon Mineralization as Affected by Drying‐Rewetting Cycles
Author(s) -
Agarwal A. S.,
Singh B. R.,
Kanehiro Y.
Publication year - 1971
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/sssaj1971.03615995003500010029x
Subject(s) - mineralization (soil science) , incubation , soil water , chemistry , organic matter , nitrogen cycle , nitrogen , environmental chemistry , zoology , soil organic matter , incubation period , ecology , biology , biochemistry , organic chemistry
The temperature of drying as well as drying‐rewetting cycles enhanced N and C mineralization in practically all soils. There was generally greater N release when incubation after drying was included than when omitted. In all unincubated soils, save the Akaka, air‐drying caused greater N release than heating at 60C, regardless of the number of drying‐rewetting cycles. The organic matter‐rich Akaka soil showed increased N mineralization with increased temperature of drying. Mineralization of C was greater in samples incubated after drying‐rewetting cycles than those subjected to incubation only. A highly significant correlation existed between rates of N and C mineralization per cycle. Significant correlation was also noted between C/N ratio of the soils and N released during drying and rewetting followed by incubation. It is proposed that in addition to microbial stimulation through drying, heat was directly responsible for the major amount of N and C release in unincubated samples by chemical alteration of otherwise unavailable organic matter and by killing off of organisms. When incubation followed the drying and heating treatment, the direct effect of heat together with increased microbial activity and associated changes during incubation accounted for N and C release.