Sulphur immobilization and availability in soils assessed using isotope dillution
Increasing recognition of S deficiency in soils has raised the need for understanding processes governing S cycling and availability in soils. However, the quantification of the two main processes of S cycling, i.e. mineralization and immobilization, remains difficult as these processes occur simult...
| Autores principales: | , , |
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| Formato: | Journal Article |
| Lenguaje: | Inglés |
| Publicado: |
Elsevier
2005
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| Materias: | |
| Acceso en línea: | https://hdl.handle.net/10568/91891 |
| _version_ | 1855535670432366592 |
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| author | Nziguheba, Generose Smolders, E. Merckx, Roel |
| author_browse | Merckx, Roel Nziguheba, Generose Smolders, E. |
| author_facet | Nziguheba, Generose Smolders, E. Merckx, Roel |
| author_sort | Nziguheba, Generose |
| collection | Repository of Agricultural Research Outputs (CGSpace) |
| description | Increasing recognition of S deficiency in soils has raised the need for understanding processes governing S cycling and availability in soils. However, the quantification of the two main processes of S cycling, i.e. mineralization and immobilization, remains difficult as these processes occur simultaneously. A modified isotope 35SO4 dilution technique was developed and used to measure the effect of sulphate (SO4) fertilization on S mineralization and immobilization in planted (pot experiment with ryegrass (Lolium multiflorum L.)) and unplanted soils (incubation). The immobilization and mineralization of S was calculated from the dynamics of stable and labelled S in soil KH2PO4 extracts containing an anion exchange membrane that concentrates SO4 and mainly excludes other S species. The mathematical analysis of the isotope dilution data differs from methods proposed earlier. The radiolabile S in unplanted soil (E value) and in ryegrass (L value) were used as a measure of total available S in soils. Sulphate immobilization rate significantly declined during incubation. Sulphate application reduced gross mineralization but surprisingly reduced SO4 immobilization. The E value significantly increased during the incubation in all soils as a result of gross mineralization, e.g. from 3.8 mg S kg−1 at day 0 to 11.5 mg S kg−1 at day 43 in the sandy soil with no sulphate addition. A full recovery in the E value of S added in (+S) treatments was achieved. Similarly, radiolabile S in the above-ground ryegrass biomass (L value) increased with S addition, with a full recovery of added S. The E and L values nearly fit a 1:1 line suggesting identical S dynamics in a planted and unplanted soil. The method proposed has operational advantages compared to methods used earlier. |
| format | Journal Article |
| id | CGSpace91891 |
| institution | CGIAR Consortium |
| language | Inglés |
| publishDate | 2005 |
| publishDateRange | 2005 |
| publishDateSort | 2005 |
| publisher | Elsevier |
| publisherStr | Elsevier |
| record_format | dspace |
| spelling | CGSpace918912024-05-15T05:12:02Z Sulphur immobilization and availability in soils assessed using isotope dillution Nziguheba, Generose Smolders, E. Merckx, Roel e value immobilization l value mineralization radioactive s ryegrass sulphate fertilization incubation Increasing recognition of S deficiency in soils has raised the need for understanding processes governing S cycling and availability in soils. However, the quantification of the two main processes of S cycling, i.e. mineralization and immobilization, remains difficult as these processes occur simultaneously. A modified isotope 35SO4 dilution technique was developed and used to measure the effect of sulphate (SO4) fertilization on S mineralization and immobilization in planted (pot experiment with ryegrass (Lolium multiflorum L.)) and unplanted soils (incubation). The immobilization and mineralization of S was calculated from the dynamics of stable and labelled S in soil KH2PO4 extracts containing an anion exchange membrane that concentrates SO4 and mainly excludes other S species. The mathematical analysis of the isotope dilution data differs from methods proposed earlier. The radiolabile S in unplanted soil (E value) and in ryegrass (L value) were used as a measure of total available S in soils. Sulphate immobilization rate significantly declined during incubation. Sulphate application reduced gross mineralization but surprisingly reduced SO4 immobilization. The E value significantly increased during the incubation in all soils as a result of gross mineralization, e.g. from 3.8 mg S kg−1 at day 0 to 11.5 mg S kg−1 at day 43 in the sandy soil with no sulphate addition. A full recovery in the E value of S added in (+S) treatments was achieved. Similarly, radiolabile S in the above-ground ryegrass biomass (L value) increased with S addition, with a full recovery of added S. The E and L values nearly fit a 1:1 line suggesting identical S dynamics in a planted and unplanted soil. The method proposed has operational advantages compared to methods used earlier. 2005-04 2018-03-23T06:48:58Z 2018-03-23T06:48:58Z Journal Article https://hdl.handle.net/10568/91891 en Limited Access Elsevier Nziguheba, G., Smolders, E. & Merckx, R. (2005). Sulphur immobilization and availability in soils assessed using isotope dilution. Soil Biology and Biochemistry, 37(4), 635-644. |
| spellingShingle | e value immobilization l value mineralization radioactive s ryegrass sulphate fertilization incubation Nziguheba, Generose Smolders, E. Merckx, Roel Sulphur immobilization and availability in soils assessed using isotope dillution |
| title | Sulphur immobilization and availability in soils assessed using isotope dillution |
| title_full | Sulphur immobilization and availability in soils assessed using isotope dillution |
| title_fullStr | Sulphur immobilization and availability in soils assessed using isotope dillution |
| title_full_unstemmed | Sulphur immobilization and availability in soils assessed using isotope dillution |
| title_short | Sulphur immobilization and availability in soils assessed using isotope dillution |
| title_sort | sulphur immobilization and availability in soils assessed using isotope dillution |
| topic | e value immobilization l value mineralization radioactive s ryegrass sulphate fertilization incubation |
| url | https://hdl.handle.net/10568/91891 |
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