Nitrogen mineralization in a sludge-amended sandy clay loam in South Africa
Sewage sludge is a solid, semi-solid or liquid byproduct produced by waste water treatment plants. It contains both compounds of agricultural value (e.g. organic material, nitrogen, phosphorous, potassium and to a lesser extent calcium, sulphur and magnesium), and pollutants (e.g. heavy metals, p...
| Autor principal: | |
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| Formato: | Otro |
| Lenguaje: | sueco Inglés |
| Publicado: |
2005
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| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/11853/ |
| _version_ | 1855571952953982976 |
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| author | Mellin, Anna-Karin |
| author_browse | Mellin, Anna-Karin |
| author_facet | Mellin, Anna-Karin |
| author_sort | Mellin, Anna-Karin |
| collection | Epsilon Archive for Student Projects |
| description | Sewage sludge is a solid, semi-solid or liquid byproduct produced by waste water
treatment plants. It contains both compounds of agricultural value (e.g. organic
material, nitrogen, phosphorous, potassium and to a lesser extent calcium, sulphur and
magnesium), and pollutants (e.g. heavy metals, pathogens and toxic organics). The
quality of sludge is dependent on its origins, i.e. whether it is domestic or industrial.
Sludge can be disposed in many ways, e.g. through land application, incineration and
land filling. Generally the least cost option, land application, has become the most
common disposal method in many countries. Sludge production has increased
dramatically due to population growth and increased indutrialization and it is very
important to reduce and utilize the digested sewage sludge and to minimize its
environmental impact. One way to achieve this is to apply sludge on farm land. Land
application has many advantages and is expected to become the dominant disposal
method in the future. This is especially true for small communities which have high
quality sludge in terms of lower concentrations of chemical pollutants. In sludge, N is
in organic form but is mineralized to NH4+ and NO3- and therefore becomes plant
available.
The main aim of the present study was to compare N mineralization between two
treatments (sludge amended soil (Sludge) and fertilization with ammonium nitrate
(AN)) and a control (C) in a incubation experiment. A second aim was to quantify the
effect of the treatments on soil pH. In both Sludge and AN, equal amounts of total N
in organic and inorganic form were added. The upper limit for the amount of sludge
farmers are allowed to apply on arable land in South Africa is 8 tonnes dry matter ha-1
year -1 and this was also the amount used in this incubation study.
In all three treatments, mineral N changed significantly during the incubation. For
Sludge and C, mineral N increased with time while it decreased for AN. This decrease
in inorganic N was unexpected and might be due to gaseous N losses. The pH did not
change significantly with time for Sludge and C but decreased significantly for AN as
the soil became more and more acidified due to proton release during nitrification. |
| format | Otro |
| id | RepoSLU11853 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish Inglés |
| publishDate | 2005 |
| publishDateSort | 2005 |
| record_format | eprints |
| spelling | RepoSLU118532017-10-13T11:12:38Z https://stud.epsilon.slu.se/11853/ Nitrogen mineralization in a sludge-amended sandy clay loam in South Africa Mellin, Anna-Karin Dept. of Soil Sciences Soil biology Sewage sludge is a solid, semi-solid or liquid byproduct produced by waste water treatment plants. It contains both compounds of agricultural value (e.g. organic material, nitrogen, phosphorous, potassium and to a lesser extent calcium, sulphur and magnesium), and pollutants (e.g. heavy metals, pathogens and toxic organics). The quality of sludge is dependent on its origins, i.e. whether it is domestic or industrial. Sludge can be disposed in many ways, e.g. through land application, incineration and land filling. Generally the least cost option, land application, has become the most common disposal method in many countries. Sludge production has increased dramatically due to population growth and increased indutrialization and it is very important to reduce and utilize the digested sewage sludge and to minimize its environmental impact. One way to achieve this is to apply sludge on farm land. Land application has many advantages and is expected to become the dominant disposal method in the future. This is especially true for small communities which have high quality sludge in terms of lower concentrations of chemical pollutants. In sludge, N is in organic form but is mineralized to NH4+ and NO3- and therefore becomes plant available. The main aim of the present study was to compare N mineralization between two treatments (sludge amended soil (Sludge) and fertilization with ammonium nitrate (AN)) and a control (C) in a incubation experiment. A second aim was to quantify the effect of the treatments on soil pH. In both Sludge and AN, equal amounts of total N in organic and inorganic form were added. The upper limit for the amount of sludge farmers are allowed to apply on arable land in South Africa is 8 tonnes dry matter ha-1 year -1 and this was also the amount used in this incubation study. In all three treatments, mineral N changed significantly during the incubation. For Sludge and C, mineral N increased with time while it decreased for AN. This decrease in inorganic N was unexpected and might be due to gaseous N losses. The pH did not change significantly with time for Sludge and C but decreased significantly for AN as the soil became more and more acidified due to proton release during nitrification. Rötslam är den slutprodukt som bildas när vatten och avlopp från hushåll och industrier renats vid reningsverken. Slammet innehåller både nyttiga substanser som organiskt material, kväve, fosfor, kalium och i en mindre utsträckning kalcium, svavel och magnesium men även föroreningar som tung metaller, sjukdomsalstrande organismer och oorganiska substanser. Alla dessa egenskaper är beroende av rötslammets ursprung. Rötslam kan användas bl.a. inom jordbruket som näringskälla, till uppfyllning av landområden eller förbrännas. Problem såsom befolkningsökning och ökad industrialisering gör att alternativ till deponering måste hittas och tack vare de många fördelarna hos rötslam så ökar nu efterfrågan inom jordbrukat. Det organiska kvävet i rötslammet mineraliseras med hjälp av mikroorganismerna i jorden till oorganiskt kväve som då blir växttillgängligt. Syftet med denna studie var att undersöka mineraliseringen av kväve i jorden för två olika behandlingar samt en kontroll där lika mängd total N tillsatts båda. I en av behandlingarna har rötslam tillsats och i den andra ammoniumnitrat. Även pH jämförs mellan behandlingarna. I Sydafrika får 8 ton torrmassa av rötslam tillföras åkermarken varje år. Denna mängd rötslam har använts även i denna studie. Resultaten visar att i rötslamsbehandlingen skedde en positiv nettomineralisering, dvs mängden oorganiskt kväve ökade med tiden, medan den minskade i ammoniumnitratbehandlingen. Denna minskning kan bero på att miljön förändrades i jorden så att N2, N2O och NO producerades. I den först nämnda behandlingen så ökade pH med tiden även om ökningen här inte var signifikant. I den tredje behandlingen så blev jorden surare med tiden på grund av oxidationen av ammonium till nitrat varvid det bildas ett överskott av protoner. 2005-10-19 Other NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/11853/1/mellin_a_171013.pdf Mellin, Anna-Karin, 2005. Nitrogen mineralization in a sludge-amended sandy clay loam in South Africa. UNSPECIFIED, Uppsala. Uppsala: (NL, NJ) > Dept. of Soil Sciences <https://stud.epsilon.slu.se/view/divisions/4023.html> urn:nbn:se:slu:epsilon-s-7823 eng |
| spellingShingle | Dept. of Soil Sciences Soil biology Mellin, Anna-Karin Nitrogen mineralization in a sludge-amended sandy clay loam in South Africa |
| title | Nitrogen mineralization in a sludge-amended sandy clay loam in South Africa |
| title_full | Nitrogen mineralization in a sludge-amended sandy clay loam in South Africa |
| title_fullStr | Nitrogen mineralization in a sludge-amended sandy clay loam in South Africa |
| title_full_unstemmed | Nitrogen mineralization in a sludge-amended sandy clay loam in South Africa |
| title_short | Nitrogen mineralization in a sludge-amended sandy clay loam in South Africa |
| title_sort | nitrogen mineralization in a sludge-amended sandy clay loam in south africa |
| topic | Dept. of Soil Sciences Soil biology |
| url | https://stud.epsilon.slu.se/11853/ https://stud.epsilon.slu.se/11853/ |