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Effect of biochar on chemistry, nutrient uptake and fertilizer mobility in sandy soil

Thesis (MScAgric)--Stellenbosch University, 2012.

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Main Author: Sika, Makhosazana Princess
Other Authors: Hardie-Pieters, Ailsa G.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2012
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access_status_str Open Access
author Sika, Makhosazana Princess
author2 Hardie-Pieters, Ailsa G.
author_browse Hardie-Pieters, Ailsa G.
Sika, Makhosazana Princess
author_facet Hardie-Pieters, Ailsa G.
Sika, Makhosazana Princess
author_sort Sika, Makhosazana Princess
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MScAgric)--Stellenbosch University, 2012.
format Thesis
id oai:scholar.sun.ac.za:10019.1/20272
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:44:22.712Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2012
publishDateRange 2012
publishDateSort 2012
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
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source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/20272 Effect of biochar on chemistry, nutrient uptake and fertilizer mobility in sandy soil Sika, Makhosazana Princess Hardie-Pieters, Ailsa G. Hoffman, J. E. Stellenbosch University. Faculty of AgriSciences. Dept. of Soil Science. Biochar Soil chemistry Nutrient leaching Soil fertility Dissertations -- Soil science Theses -- Soil science Dissertations -- Agriculture Theses -- Agriculture Soils -- South Africa -- Western Cape Thesis (MScAgric)--Stellenbosch University, 2012. ENGLISH ABSTRACT: Biochar is a carbon-rich solid material produced during pyrolysis, which is the thermal degradation of biomass under oxygen limited conditions. Biochar can be used as a soil amendment to increase the agronomic productivity of low potential soils. The aim of this study was to investigate the effect of applying locally-produced biochar on the fertility of low-nutrient holding, sandy soil from the Western Cape, and to determine the optimum biochar application level. Furthermore, this study investigates the effect of biochar on the leaching of an inorganic nitrogen fertilizer and a multi-element fertilizer from the sandy soil. The biochar used in this study was produced from pinewood sawmill waste using slow pyrolysis (450 °C). The soil used was a leached, acidic, sandy soil from Brackenfell, Western Cape. In the first study, the sandy soil mixed with five different levels of biochar (0, 0.05, 0.5, 0.5 and 10.0 % w/w) was chemically characterised. Total carbon and nitrogen, pH, CEC and plant-available nutrients and toxins were determined. The application of biochar resulted in a significant increase in soil pH, exchangeable basic cations, phosphorus and water holding capacity. A wheat pot trial using the biochar-amended soil was carried out for 12 weeks and to maturity (reached at 22 weeks). The trial was conducted with and without the addition of a water-soluble broad spectrum fertilizer. Results showed that biochar improved wheat biomass production when added at low levels. The optimum biochar application level in the wheat pot trial was 0.5 % (approximately 10 t ha-1 to a depth of 15 cm) for the fertilized treatments (21 % biomass increase), and 2.5 % (approximately 50 t ha-1 to a depth of 15 cm) for unfertilized treatments (29 % biomass increase). Since most biochars are alkaline and have a high C:N ratio, caution should be taken when applying it on poorly buffered sandy soil or without the addition of sufficient nitrogen to prevent nutrient deficiencies. In the second study, leaching columns packed with sandy soil and biochar (0, 0.5, 2.5 and 10.0 % w/w) were set up to determine the effect of biochar on inorganic nitrogen fertilizer leaching over a period of 6 weeks. It was found that biochar (0.5, 2.5, and 10.0 % w/w) significantly reduced the leaching of ammonium (12, 50 and 86 % respectively) and nitrate (26, 42 and 95 % respectively) fertilizer from the sandy soil. Moreover, biochar (0.5 %) significantly reduced the leaching of basic cations, phosphorus and certain micronutrients. This study demonstrated the potential of biochar as an amendment of acidic, sandy soils. Our findings suggest that an application rate of 10 t ha-1 should not be exceeded when applying biochar on these soils. Furthermore, biochar application can significantly reduce nutrient leaching in sandy agricultural soils. AFRIKAANSE OPSOMMING: Biochar is ʼn koolstof-ryke, soliede materiaal geproduseer gedurende pirolise, wat die termiese degradasie van biomassa onder suurstof-beperkte omstandighede behels. Biochar kan gebruik word as ʼn grondverbeterings middel om die agronomiese produktiwiteit van grond te verhoog. Die doel van hierdie studie was om die effek van plaaslike vervaardigde biochar op die vrugbaarheid van die sanderige grond van die Wes-Kaap te ondersoek, en om die optimale biochar toedieningsvlak te bepaal. Verder, het hierdie studie die effek van biochar op die loging van anorganiese stikstof kunsmis en ‘n multi-elementkunsmis op sanderige grond ondersoek. Die biochar wat in hierdie studie gebruik is, is van dennehout saagmeul afval vervaardig d.m.v. stadige pirolise (450 °C). Die grond wat in hierdie studie gebruik is, is ‘n geloogde, suur, sanderige grond van Brackenfell, Wes-Kaap. In die eerste studie, is ‘n chemiesie ondersoek van die sanderige grond wat vermeng met is met vyf verskillende vlakke van biochar (0, 0.05, 0.5 en 10.0 % w/w) uitgevoer. Totale koolstof en stikstof, pH, KUK, en plant-beskikbare voedingstowwe en toksiene is in die grondmengsels bepaal. Die toediening van biochar het ‘n veroorsaak dat die grond pH, uitruilbare basiese katione, fosfor en waterhouvermoë beduidend toegeneem het. ‘n Koringpotproef was uitgevoer vir 12 weke en ook tot volwassenheid (wat op 22 weke bereik was) om die effek van die biochar op die sanderige grond teen die vyf verskillende toedieningsvlakke te bepaal. Daar was behandelings met en sonder die bykomstige toediening van ‘n wateroplosbare breë-spektrumkunsmis. Resultate toon dat die toediening van biochar teen lae vlakke koringbiomassa produksie verbeter. Die optimale biochar toedieningsvlak in die koringpotproef is 0.5 % (omtrent 10 t ha-1 tot ‘n diepte van 15 cm) vir die bemeste behandeling (21 % biomassa toename), en 2.5 % (omtrent 50 t ha-1 na ‘n diepte van 15 cm) vir onbemeste behandelings (29 % biomassa toename). Aangesien die meeste biochars alkalies is en ‘n hoë C:N verhouding besit, moet sorg gedra word wanneer dit op swak-gebufferde of lae N-houdende sanderige gronde toegedien word. Die resultate het aangedui dat die biochar versigtig aangewend moet word om grond oorbekalking te voorkom. In die tweede studie, was kolomme gepak met 2.0 kg van die sanderige grond gemeng met biochar (0, 0.05, 0.5, 2.5 en 10.0 % w/w) om die effek van biochar op die loging die anorganiese stikstof kunsmis oor ‘n tydperk van 6 weke om vas te stel. Daar is gevind dat biochar (0.5, 2.5 en 10.0 % w/w) die loging van ammonium (12, 50 en 86 % onderskeidelik) en nitraat (26, 42 en 95 % onderskeidelik) op sanderige grond aansienliek verminder. Verder, het biochar (0.5 %) die loging van basiese katione, fosfor en mikrovoedingstowwe aansienlik verminder. Hierdie studie het die potensiaal van biochar as verbeteringmiddel van suur, sanderige grond gedemonstreer. Ons bevindinge dui daarop aan dat ‘n toepassing vlak van 10 t ha-1 moet nie oorskry word nie wanneer biochar op hierdie gronde toegedien word. Die toediening van biochar op sanderige grond kan die loging van voedingstowwe aansienlik verlaag. Masters 2012-02-02T14:04:36Z 2012-03-30T10:58:56Z 2012-02-02T14:04:36Z 2012-03-30T10:58:56Z 2012-03 Thesis http://hdl.handle.net/10019.1/20272 en_ZA Stellenbosch University 123 p. : ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Biochar
Soil chemistry
Nutrient leaching
Soil fertility
Dissertations -- Soil science
Theses -- Soil science
Dissertations -- Agriculture
Theses -- Agriculture
Soils -- South Africa -- Western Cape
Sika, Makhosazana Princess
Effect of biochar on chemistry, nutrient uptake and fertilizer mobility in sandy soil
title Effect of biochar on chemistry, nutrient uptake and fertilizer mobility in sandy soil
title_full Effect of biochar on chemistry, nutrient uptake and fertilizer mobility in sandy soil
title_fullStr Effect of biochar on chemistry, nutrient uptake and fertilizer mobility in sandy soil
title_full_unstemmed Effect of biochar on chemistry, nutrient uptake and fertilizer mobility in sandy soil
title_short Effect of biochar on chemistry, nutrient uptake and fertilizer mobility in sandy soil
title_sort effect of biochar on chemistry nutrient uptake and fertilizer mobility in sandy soil
topic Biochar
Soil chemistry
Nutrient leaching
Soil fertility
Dissertations -- Soil science
Theses -- Soil science
Dissertations -- Agriculture
Theses -- Agriculture
Soils -- South Africa -- Western Cape
url http://hdl.handle.net/10019.1/20272
work_keys_str_mv AT sikamakhosazanaprincess effectofbiocharonchemistrynutrientuptakeandfertilizermobilityinsandysoil