Use of the “Acetylene blockage” technique for assaying denitrification in a salt marsh

1979 ◽  
Vol 52 (4) ◽  
pp. 315-320 ◽  
Author(s):  
C. D. Van Raalte ◽  
D. G. Patriquin
Keyword(s):  
Salt Marsh ◽  
Acetylene Blockage Technique ◽  
Acetylene Blockage

SEASONAL PATTERNS OF DENITRIFICATION AND LEAF NITRATE REDUCTASE ACTIVITY IN A CORN FIELD

1978 ◽  
Vol 58 (2) ◽  
pp. 283-285 ◽  
Author(s):  
D. G. PATRIQUIN ◽  
J. C. MacKINNON ◽  
K. I. WILKIE
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reductase Activity ◽  
General Trend ◽  
Reductase Activity ◽  
Seasonal Patterns ◽  
Assay Procedure ◽  
Acetylene Blockage Technique ◽  
Acetylene Blockage ◽  
Leaf Nitrate

Denitrification in soil around the bases of corn stalks, determined by the "acetylene blockage technique," exhibited a general trend of decline from June to September. Leaf nitrate reductase activity, determined by an in vivo assay procedure, was low in June and July, and then exhibited a pronounced maximum at the time of tasselling.

Denitrification and nitrate leaching during the fall and winter following dairy cattle slurry application

1997 ◽  
Vol 77 (2) ◽  
pp. 231-240 ◽  
Author(s):  
J. W. Paul ◽  
B. J. Zebarth
Keyword(s):  
Dairy Cattle ◽  
Soil Profile ◽  
High Water ◽  
High Rate ◽  
Cattle Slurry ◽  
Manure Application ◽  
Total N ◽  
Acetylene Blockage Technique ◽  
Acetylene Blockage ◽  
Dairy Cattle Slurry

Conditions in soils of south-coastal British Columbia during the fall and winter favor both NO3− leaching and denitrification. Estimates of NO3− leaching were made on a coarse-textured soil having a high water table (Sumas) and a well-drained, medium-textured soil (Agassiz) in each of 1991 and 1992, following application of 0, 300 and 600 kg total N ha−1 as dairy cattle slurry at the end of September. Leaching was calculated by measuring NH4+ and NO3− concentrations biweekly to 90 cm depth and subtracting denitrification losses. Denitrification estimates were made using the acetylene blockage technique on intact cores taken to 43 cm depth at biweekly intervals from the 0 and 600 kg N ha−1 treatments. Most of the NO3− disappeared from the 90 cm soil profile by January in both years. At the high rate of manure application, denitrification losses were 29 and 20 kg N ha−1 at Agassiz in 1991 and 1992, and 48 and 17 kg N ha−1 at Sumas in 1991 and 1992, respectively. Denitrification losses in the non-manured treatments ranged from 3 to 16 kg N ha−1 Significant denitrification losses occurred at the 15- to 28-cm and the 30-cm to 43-cm depths, indicating that denitrification measurements at these depths are important. Leaching losses ranged from 60 to 188 kg N ha−1 from the control treatments, and from 102 to 241 kg N ha−1 following the highrate of manure application. Denitrification accounted for up to 17% of the NO3− loss from the soil profile, indicating that the majority of the NO3− was leached. Key words: Acetylene blockage technique, denitrification rate, air-filled porosity, manure

Denitrifïcations in Sediments from the Hyporheic Zone Adjacent to a Small Forested Stream

1990 ◽  
Vol 47 (6) ◽  
pp. 1140-1147 ◽  
Author(s):  
John H. Duff ◽  
Frank J. Triska
Keyword(s):  
Nitrous Oxide ◽  
Organic Carbon ◽  
Hyporheic Zone ◽  
Stream Water ◽  
Stream Channel ◽  
Monitoring Wells ◽  
Nitrous Oxide Production ◽  
Acetylene Blockage Technique ◽  
Acetylene Blockage

Denitrification was assayed by the acetylene blockage technique in hyporheic sediments. Samples were obtained along transects perpendicular to the stream at two sites: (1) the base of a slope dominated by old-growth redwood and (2) the base of a slope dominated by alder regenerating from a clearcut in 1965. Denitrification was evident at in situ nitrate concentrations at all locations tested. Activity was stimulated by nitrate but nitrate plus glucose had no additional effect. Denitrifying potentials increased with increasing distance from the stream channel. Dissolved oxygen was 100% of the concentration expected in equilibrium with the atmosphere in water obtained from monitoring wells immediately adjacent to the stream but was as low as 7% of the expected value in water 11.4 m inland. Both nitrate and dissolved organic carbon decreased over summer in wells at the base of the alder-forested slope. A 48-h injection of nitrate-amended stream water into hyporheic water 8.4 m inland stimulated nitrous oxide production in the presence of acetylene. Nitrous oxide was generated as nitrate and acetylene were co-transported to a well 13 m down-gradient. The acetylene-block experiments coupled with the chemistry data suggest that denitrification can modify the chemistry of water during passage through the hyporheic zone.

Urbanization impacts on production and recruitment of Fundulus heteroclitus in salt marsh creeks

2020 ◽  
Vol 645 ◽  
pp. 187-204
Author(s):  
PJ Rudershausen ◽  
JA Buckel
Keyword(s):  
Salt Marsh ◽  
Salt Marshes ◽  
Fundulus Heteroclitus ◽  
Multiple Factor Analysis ◽  
Southeastern Usa ◽  
Density Dependent ◽  
Dependent Relationship ◽  
Juvenile Abundance ◽  
The Relationship ◽  
Throw Trap

It is unclear how urbanization affects secondary biological production in estuaries in the southeastern USA. We estimated production of larval/juvenile Fundulus heteroclitus in salt marsh areas of North Carolina tidal creeks and tested for factors influencing production. F. heteroclitus were collected with a throw trap in salt marshes of 5 creeks subjected to a range of urbanization intensities. Multiple factor analysis (MFA) was used to reduce dimensionality of habitat and urbanization effects in the creeks and their watersheds. Production was then related to the first 2 dimensions of the MFA, month, and year. Lastly, we determined the relationship between creek-wide larval/juvenile production and abundance from spring and abundance of adults from autumn of the same year. Production in marsh (g m-2 d-1) varied between years and was negatively related to the MFA dimension that indexed salt marsh; higher rates of production were related to creeks with higher percentages of marsh. An asymptotic relationship was found between abundance of adults and creek-wide production of larvae/juveniles and an even stronger density-dependent relationship was found between abundance of adults and creek-wide larval/juvenile abundance. Results demonstrate (1) the ability of F. heteroclitus to maintain production within salt marsh in creeks with a lesser percentage of marsh as long as this habitat is not removed altogether and (2) a density-dependent link between age-0 production/abundance and subsequent adult recruitment. Given the relationship between production and marsh area, natural resource agencies should consider impacts of development on production when permitting construction in the southeastern USA.

Demographics of the Ribbed Mussel Geukensia demissa (Dillwyn, 1817) and the Effects of Its Simulated Manual Harvest on Salt Marsh Health in South Carolina, Usa

2020 ◽  
Vol 39 (1) ◽  
pp. 67 ◽  
Author(s):  
Asa R. Julien ◽  
Andrew W. Tweel ◽  
Nancy Hadley ◽  
Peter R. Kingsley-Smith
Keyword(s):  
South Carolina ◽  
Salt Marsh ◽  
Geukensia Demissa ◽  
Ribbed Mussel
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