+ Site Statistics
References:
52,654,530
Abstracts:
29,560,856
PMIDs:
28,072,755
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn

+ Translate
+ Recently Requested

Diffusional constraints on denitrification in soil



Diffusional constraints on denitrification in soil



Soil Science Society of America Journal 49(3): 651-657



A model for NO3- reduction and diffusion in aggregated soils is presented and used in conjunction with a derived constant, the Thiele modulus, to examine the conditions which could contribute to a NO3- diffusion limitation of denitrification. The Thiele modulus is a function of the anaerobic radius of an aggregate, the maximum rate of NO3- reduction for a given soil, the Km value for NO3- reduction, and the intra-aggregate NO3- diffusion coefficient. Results from this theoretical exercise suggested that the anaerobic radius is the most important factor in determining whether denitrification is limited by NO3- diffusion. The model predicts that under anaerobic conditions, only soils with a mean aggregate radius greater than 2 mm will experience a NO3- diffusion limitation. This limitation may not be effective in practice if the bulk NO3- concentration is much greater (100 times) than the Km for NO3- reduction; this appears to often be the case in fertilized soils but may not be the case in soils of natural ecosystems. Under aerobic conditions, a diffusion limitation will exist in most aggregated soils, since only large aggregates have anaerobic microsites (i.e., large anaerobic radii) where denitrification can occur. A C limitation, through its lowering of the maximum denitrification rate, lessens the magnitude of any existing NO3- diffusion limitation. Diffusive limitations were experimentally examined in 2 ways. First, the ratio of denitrification rates of anaerobic cores relative to anaerobic slurries were used to indicate the degree of any substrate supply limitation; the slurry rates were always greater suggesting either. NO3- or C was limiting. Second, soil cores were preincubated with either NO3- or a diffusible C source (succinate) at 4.degree. C to allow diffusion but to suppress biological responses. C, rather than NO3- was limiting denitrification rates in this clay loam soil. These experimental results were in agreement with model predictions.

(PDF emailed within 0-6 h: $19.90)

Accession: 001336482

Download citation: RISBibTeXText

DOI: 10.2136/sssaj1985.03615995004900030025x



Related references

Relationships between field-measured denitrification losses, CO2 formation and diffusional constraints. Soil biology and biochemistry 26(7): 891-899, 1994

Diffusional constraints on microbial processes in soil. Soil Science 154(4): 300-307, 1992

Measuring denitrification activity in soils under pasture: optimizing conditions for the short-term denitrification enzyme assay and effects of soil storage on denitrification activity. Soil Biology and Biochemistry 28(3): 409-417, 1996

Spatial variability of denitrification rate denitrification enzymes moisture ph and nitrate in agricultural soil. Abstracts of the Annual Meeting of the American Society for Microbiology 83: N36, 1983

Diffusional constraints on energy metabolism in skeletal muscle. Journal of Theoretical Biology 254(2): 417-429, 2008

Dynamic interplay between microbial denitrification and antibiotic resistance under enhanced anoxic denitrification condition in soil. Environmental Pollution 222: 583-591, 2017

Denitrification in soil. I. Methods of investigation. II. Factors affecting denitrification. J. agric. Sci, 51: 22-52, 1958

Stochastic models of soil denitrification driven by denitrification capacity phase 1 and carbon dioxide production rates. Abstracts of the Annual Meeting of the American Society for Microbiology 88: 253, 1988

Critique of Relationships among microbial populations and rates of nitrification and denitrification in a Hanford soil. denitrification in British soils. Nitrogen in the Environment: 365-377, 1978

Critique of Relationships among microbial populations and rates of nitrification and denitrification in a Hanford soil by P.R.Day, H.E.Doner and A.D.McLaren. Modeling of rates of nitrification and denitrification in soil. Nitrogen in the environment Volume 2 Soil plant nitrogen relationships [Nielsen, DR; MacDonald, JG, Editors]: 379-382, 1978

Denitrification potential of soil in a riparian zone and a swine wastewater spray field as measured by denitrification enzyme analysis. Program and Abstracts - Symposium on Biogeochemistry of Wetlands 6: 113, 1999

Critique of Relationships among microbial populations and rates of nitrification and denitrification in a Hanford soil by P.R. Day, H.E. Doner and A.D. McLaren. Denitrification in British soils. Nitrogen in the environment Volume 2 Soil plant nitrogen relationships [Nielsen, DR; MacDonald, JG, Editors]: 365-377, 1978

Soil denitrification in three cropping systems characterized by differences in nitrogen and carbon supply ii. water and nitrate effects on the denitrification process. Plant and Soil 138(2): 273-286, 1991

Measurement of denitrification rate in undisturbed soil cores under different temperature and moisture conditions using nitrogen 15 tracer technique 2. factors affecting denitrification. Swedish Journal of Agricultural Research 19(1): 35-44, 1989

Denitrification in soil II Factors affecting denitrification. The Journal of Agricultural Science 51(1): 40, 1958