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Mineralization, Nitrification, and Denitrification in Histosols of Northern Minnesota
Author(s) -
Zanner C. W.,
Bloom P. R.
Publication year - 1995
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/sssaj1995.03615995005900050042x
Subject(s) - nitrification , histosol , mineralization (soil science) , denitrification , soil water , chemistry , nitrogen cycle , simultaneous nitrification denitrification , environmental chemistry , blackwater , agronomy , nitrogen , zoology , environmental science , soil organic matter , soil science , environmental engineering , biology , organic chemistry , soil biodiversity
Water content and temperature are influences on N mineralization, nitrification, and denitrification rates in drained Histosols. To look at possible differences in these rates and to enable comparisons to mineral soils, we collected soil samples from two Minnesota Histosols planted in cultivated wild rice ( Zizania palustris L.), incubated amended subsamples at 4, 7, 10, 16, and 22°C, and monitored changes in NH 4 ‐N with time. Amendments used were plus or minus NH 4 and plus or minus nitrapyrin. Net mineralization rates for Soil 1 (plus‐nitrapyrin treatment) increased from 0.30 to 2.0 mg N kg −1 dry soil d −1 from 4 to 22°C. Nitrification and denitrification occurred simultaneously, with lower denitrification than nitrification rates. Nitrification rates (determined from the zero‐order plots of the disappearance of NH 4 ‐N with time in the plus‐NH 4 samples) increased from 4 to 22°C (Soil 1, 17–99 mg N kg −1 d −1 ; Soil 2, 11–40 mg N kg −1 d −1 ). Soil 1 nitrified faster than most mineral soils; Soil 2 was comparable with many mineralsoils. Denitrification rates for Soil 1, determined from the decrease in total inorganic N (NH 4 ‐N + NO 3 ‐N; plus‐NH 4 samples), increased from 9 mg N kg −1 d −1 at 4°C to 53 mg N kg −1 d −1 at 22°C. There were no differences between the two experimental water contents (corresponding to soil water pressure heads of ‐25 and −50 cm) for any of these rates. The high water‐holding capacity of Histosols increases the potential for simultaneous nitrification and denitrification and will result in removal of native and applied NH 4 from the system, thus affecting N use efficiency of both wild rice and upland crops grown on Histosols.