Show simple item record

dc.contributor.advisorLe Roux, P. A. L.
dc.contributor.authorFraenkel, Coenraad Hendrik
dc.contributor.otherVan Rensburg, L. D.
dc.date.accessioned2015-08-14T09:22:43Z
dc.date.available2015-08-14T09:22:43Z
dc.date.issued2008-11
dc.identifier.urihttp://hdl.handle.net/11660/876
dc.description.abstractEnglish: Soils vary at all levels of observation. When describing soil physical or chemical properties we initially think in terms of homogeneous material. However, for characterizing the land use ability it is necessary to consider variability within and between soil map units as soils vary significantly over a land and within a homogeneous soil. The combinations of knowledge about soil interrelationships and the representation of the soil variability will be useful in the process of characterizing the variability of soil properties for different land use abilities, for example precision agriculture. The objectives of this study were therefore to (i) characterize the spatial variation of selected soil properties in and between map units (ii) describe the relationship between physical properties of selected soil forms and the root density of maize (iii) characterize the hydrology of the Tukulu, Sepane and Bloemdal soil forms at Paradys. A field experiment was conducted on a 55 ha cultivated field on the experimental farm of the University of the Free State, Paradys (S -32°35’21’’, E -77°43’6’’). The experimental site was subdivided into 75 experimental plots. For objective 1 all 75 plots were analysed for pH, Ca, K, Mg, Na and 7 texture classes . For objective 2, 13 plots were sel ected from the 75 experimental plots to cover a range of relative dry biomass yield plots. Root samples and soil samples were taken per master horizon. They were analysed for silt + clay content , water stable aggregates, modulus of rupture, bulk density and organic carbon content. For objective 3 , three modal profiles were selected and the instantaneous profile method was used to describe the volumetric wetness – time relationship, the hydraulic head – depth relationships and the hydraulic conductivity. It was clear that most of the soil physical and chemical properties had a strong relationship with clay. It was found that there was a higher variation between map units than within map units . Despite any variation Inverse Distance Weighting (IDW) fairly accurately predicted the variation within map units varying from 97% to 99% irrespective of horizon or soil. It also accurately predicted the variation between map units varying from 91% to 94%. It was found that the A and C horizon has varying interrelationship due to varying silt + clay contents. The B horizon is the main factor that distinguishes the three soils. The silt + clay content of the B horizon for Tukulu varied between 31% and 34%, the Sepane between 49% and 55%, and the Bloemdal between 28% and 34%. The Bloemdal had the highest root length index (RLI) followed by the Sepane and Tukulu. It was clear that in the case of the Bloemdal and Tukulu , the C horizon controls the hydrology, while in the case of the Sepane it is the B horizon. It may be concluded that the variation in soil properties is higher between than within map units. Soil physical properties have a close interrelationship and varying effects on the RLI. The hydrology of the Bloemdal and Tukulu is influenced by the C horizon, while the Sepane is influenced by the B horizon.en_ZA
dc.description.abstractAfrikaans: Grond varieër merkwaardig. Grond is geneigd om beskryf te word in terme van ‘n homogene liggaam. Alhoewel, as daar gekyk word na ‘n grond se vermoë vir ‘n sekere grondgebruik, moet dit beskryf word in terme van die variasie in- en tussen kaart eenhede. Die rede hiervoor is dat grond betekenisvol verskil oor ‘n landskap en in ‘n profiel. ‘n Kombinasie oor die interverwantskap tussen grondeienskappe en die vermoë om dit ten toon te stel, is handig in die proses om grondvariasie vir sekere landelike gebruike te karakteriseer. Die doelstellings vir die studie was dus as volg: om (i) die variasie van grondeienskappe in en tussen kaarteenhede te karakteriseer (ii) die interverwantskap tussen grondfisiese eienskappe en die worteldigtheid van mielies te beskryf, en laastens (iii) om die hidrologiese eienskappe van die Bloemdal, Tukulu en Sepane op Paradys te beskryf. ‘n 55 ha Geploegde land is gebruik in ‘n veld eksperiment op die proefplaas van die Universiteit van die Vrystaat (-32°35’21’ ’ S , - 77°43’6’’O). Die proefterrein was onderverdeel in 75 proefpersele . Vir doelstelling 1 was die total 75 persele geanaliseer om pH, Ca, K, Mg, Na en 7 tekstuur klasse te bepaal. Vir doelstelling 2 was 13 persele geselekteer wat gevarieer het volgens relatiewe biomassa. Op die persele is wortel- en grondmonsters geneem. Die grondmonsters is geanaliseer vir slik + klei, water stabiele aggregate, breeksterkte, brutodigtheid en organiese koolstofinhoud. Vir doelstelling 3 was die velddreineringsmetode gebruik om die volumetriese water inhoud – tyd verhouding, die hidroliese druk – diepte verhoud ng en die hidroliese geleidingvermoë – diepte verhouding te karakteriseer. Vanaf die studie was dit duidelik dat die grondfisiese en -chemise eienskappe ‘n sterk verwantskap het met die slik + klei inhoud. Daar was ‘n groter vari asie tussen kaarteenhede as binne kaarteenhede. Nogtans het “Inverse Distance Weighting (IDW)” die variasie binne (97% tot 99%) en tussen kaarteenhede (91% tot 94%) redelik akkuraat voorspel ongeag die horison of grondtipe. Die A en C horison het variërende interverwantskappe getoon. Die B horison is die hooffaktor wat tussen die drie grondtipes onderskei . Die slik + klei inhoud van die B horison het tussen 31% en 34% gevarieër, die Sepane tussen 49% en 55% en die Bloemdal tussen 28% en 34%. Die Bloemdal het die hoogste ooreenstemmende WLI gehad, gevolg deur die Sepane en Tukulu grondtipes. Dit was duidelik dat in die geval van die Bloemdal en Tukulu, die C horison die hooffaktor is wat die vloei van water beïnv loed deur die profiel, terwyl die B horison in die geval van die Sepane die hoof faktor was. Die variasie was groter tussen kaart eenhede as in kaart eenhede. Die grondfisiese eienskappe het ‘n sterk interverwantskap en variërende invloede op WLI getoon. Die vloei van water in die Bloemdal en Tukulu word hoofsaaklik beïnvloed deur die onderliggende C horison, terwyl die B horison in die geval van die Sepane vloei beïnvloed het.
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectSoil chemistry -- South Africa -- Free Stateen_ZA
dc.subjectSoil mapping -- South Africa -- Free Stateen_ZA
dc.subjectLandforms -- South Africa -- Free Stateen_ZA
dc.subjectDissertation (M.Sc. (Soil, Crop and Climate Sciences))--University of the Free State, 2008en_ZA
dc.titleSpatial variatbility [sic] of selected soil properties in and between map unitsen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record