Repository logo
 

Mineralizable soil nitrogen: amounts and extractability ratios

Simple item page
dc.contributor.authorPaul, Eldor A., author
dc.contributor.authorJuma, N. G., author
dc.contributor.authorSoil Science Society of America, publisher
dc.date.accessioned2007-01-03T07:05:42Z
dc.date.available2007-01-03T07:05:42Z
dc.date.issued1984-01
dc.description.abstractStudies were conducted on a 15N-labeled Weirdale loam, a Dark Gray Chernozemic soil (Boralfic Boroll) to (i) determine the amounts of N released by several methods previously used to obtain an estimate of potentially mineralizable N, (ii) determine their 15N enrichment and extractability ratios, and (iii) compare the results from the above with the N mineralized during incubation and NH+4 released by the chloroform fumigation incubation technique. The NH+4-N accumulated during 10 d in fumigated soils accounted for ∼1% of total N, was highly labeled, and had extractability ratios of 6.6 to 7.4. These ratios were similar to ones obtained for N mineralized during incubation of unfumigated soils. Ammonium-N extracted with dilute acidic permanganate solution (0.01M KMnO4 in 0.1 or 0.5M H2SO4) accounted for 0.72 to 0.84% of total N and had extractability ratios ranging from 3.4 to 3.9. A stronger solution of acidic permanganate extracted more N that was less enriched. Dilute sulfuric acid extracted NH+4 and organic N that had extractability ratios of < 3. Ammonium-N released by autoclaving the soil accounted for ∼1% of total N and had extractability ratios ranging from 0.6 to 0.9. Acid hydrolysis showed that 72% of total N was hydrolyzable, 32% was amino acid-N and 20% was NH+4 released on hydrolysis. The extractability ratio for NH+4 released on hydrolysis was 1.7 and was significantly (P < 0.01) greater than extractability ratios of hydrolyzable N and amino acid-N. The similarity and high extractability ratios of NH+4 released after fumigation and NO-3-N accumulating during aerobic incubation indicated that the fumigation extracted a biologically meaningful fraction. The biomass was responsible for only 15 to 25% of the net N mineralized during a 12-week incubation. Results indicated that (i) extraction of a highly labeled N pool in soil can only partly explain the source of N being mineralized, (ii) N is mineralized from several pools, and (iii) there is a remote possibility that a single extractant can extract the variety of N compounds undergoing mineralization and immobilization in soil.
dc.format.mediumborn digital
dc.format.mediumarticles
dc.identifier.bibliographicCitationJuma, N. G. and E. A. Paul, Mineralizable Soil Nitrogen: Amounts and Extractability Ratios. Soil Science Society of America Journal 48, no. 1 (January-February 1984): 76-80. https://dx.doi.org/10.2136/sssaj1984.03615995004800010014x.
dc.identifier.doihttps://dx.doi.org/10.2136/sssaj1984.03615995004800010014x
dc.identifier.urihttp://hdl.handle.net/10217/85527
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relation.ispartofFaculty Publications
dc.rights©1984 Soil Science Society of America.
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.subjectbiomass N
dc.subjectN supply power
dc.subjectnonbiomass active N
dc.subjecttotal N
dc.subjectN availability ratios
dc.subjectNO
dc.subjectactive N phase
dc.titleMineralizable soil nitrogen: amounts and extractability ratios
dc.typeText

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
NREL_Paul_Juma_sssaj_48_76-80.pdf
Size:
595 KB
Format:
Adobe Portable Document Format
Description:
Mineralizable soil nitrogen : amounts and extractability ratios
Download

Collections

Faculty Publications
Faculty Publications
Paul (Eldor A.) Collection
Paul (Eldor A.) Collection