Studies on the Carbon and Nitrogen Cycles in the Soil. VIII. The Nature of the Organic Nitrogen Compounds of the Soil: “Non-Humic” Nitrogen

Soil microorganisms play an important role in the organic matter transformation process. The soil microorganisms also are in symbiotic relationship with plants. At the same time, soil microorganisms are sensitive to both anthropogenic and natural habitat changes. Particular characteristics of organic matter (the C:N relation, pH, the content the content of assimilated nutrients, the xenobiotics etc.) modify the biotic conditions of the soils. This particularly concerns the microorganisms which carry out the changes in the mineral and organic nitrogen compounds and the transformation of the external organic matter. The first aim of this work was to assess the influence of the sewage sediments and the manure on the phytosanitary potential of the soil environment. The second aim of this article was to estimate the number and activity of microorganisms which carry out the transformation of carbon and nitrogen compounds. This work showed the stimulating effect of the external organic matter both on the number and on the activity of most of the physiological groups. The manure mainly stimulated ammonificators, amylolitic microorganisms and Azotobacter sp. The sewage sediments mainly stimulated ammonificators, nitrifiers of I phase and cellulolytic microorganisms. The statistically significant impact of the physio-chemical soil habitat on the biological activity of the analyzed groups of microbes was also noted.

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Examining the coupling of carbon and nitrogen cycles in Appalachian streams: the role of dissolved organic nitrogen

Ecology ◽

10.1890/10-0899.1 ◽

2011 ◽

Vol 92 (3) ◽

pp. 720-732 ◽

Cited By ~ 35

Author(s):

Brian D. Lutz ◽

Emily S. Bernhardt ◽

Brian J. Roberts ◽

Patrick J. Mulholland

Keyword(s):

Dissolved Organic Nitrogen ◽

Organic Nitrogen ◽

Carbon And Nitrogen ◽

Nitrogen Cycles ◽

Appalachian Streams

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Effect of peat samples drying on measured content of carbon and nitrogen fractions

Soil Annual Science ◽

10.2478/ssa-2013-0020 ◽

2013 ◽

Vol 64 (4) ◽

pp. 130-134 ◽

Cited By ~ 1

Author(s):

Jerzy Jonczak

Keyword(s):

Organic Carbon ◽

Total Organic Carbon ◽

Total Nitrogen ◽

Dissolved Organic Nitrogen ◽

Organic Nitrogen ◽

Mineral Nitrogen ◽

Nitrogen Compounds ◽

Carbon And Nitrogen ◽

Nitrogen Fractions ◽

Initial Stage

Abstract The aim of the study was to compare the content of carbon and nitrogen fractions in fresh and dried samples of peat. The samples were extracted in 0.25 mol KCl·dm.-3, 0.25 mol H2SO4·dm.-3 and 2.5 mol H2SO4·dm.-3. Based on the extractions and analysis of total organic carbon (TOC) and total nitrogen (TN) following fractions of carbon and nitrogen were isolated: nonhydrolyzable carbon (NHC) and nitrogen (NHN), hardly hydrolyzable carbon (HHC) and nitrogen (HHN), easy hydrolyzable carbon (EHC) and nitrogen (EHN), dissolved organic nitrogen (DON), and its ammonium (NH4.-N) and nitrate (NO3.-N) form. Large differences between fresh and dried samples were observed in the content of some analyzed fractions . especially NO3.-N, NH4.-N, DON and HHC. 1.6.3.5 times higher concentrations of NO3.-N were observed in dry samples in comparison with fresh. In dried samples were also observed higher concentrations of NH4.-N and DON. In general lower concentrations of EHN, NHN, HHC and higher of HHN and EHC were observed in dried samples in comparison to fresh. Higher content of mineral nitrogen, as well as DON and DOC in dried samples, is probably an effect of mineralization of carbon and nitrogen compounds during initial stage of drying. The obtained data suggest, that the content of NO3.-N, NH4.-N, DON and EHC analyzed in dried samples of peat is overestimated. Extractions of the fractions from organic samples should be done based on fresh samples, just after sampling

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Studies on the Carbon and Nitrogen Cycles in the Soil VI. The Extraction of the Organic Nitrogen of the Soil with Alkali

The Journal of Agricultural Science ◽

10.1017/s0021859600053636 ◽

1932 ◽

Vol 22 (2) ◽

pp. 297-299 ◽

Cited By ~ 10

Author(s):

R. P. Hobson ◽

H. J. Page

Keyword(s):

Organic Nitrogen ◽

Alkali Extraction ◽

Carbon And Nitrogen ◽

Nitrogen Cycles

The alkali-extraction of the nitrogen from soils of certain plots of the classical permanent experiments on Barnfield and Broadbalk at Rothamsted, follows a closely similar course to the alkali-extraction of carbon from the same soils.

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