Thesis (MScAgric (Soil Science))--University of Stellenbosch, 2011. / Includes bibliography. / ENGLISH ABSTRACT:
The natural resource condition or health has been accepted as a valuable indicator of
sustainable land use. The assessment of soil health (quality) has become a valuable tool in
determining the sustainability of land management systems. This work aims to evaluate the
sustainability of soil management practices in agricultural extension for vineyards in
Robertson, South Africa based, on the current approach of the concept of soil health and
soil quality, as well as to briefly explore the present reservations regarding the definition of
the concept. The soil management treatments include a mechanical weed control, chemical
weed control, annual addition of straw mulch, annual cover crop and perennial cover crop.
The objective of study is to (i) identify suitable soil health (quality) indicators for vineyards in
the study area; (ii) analyze the soil health (quality) indicators for different soil management
treatments; (iii) evaluate the effect of various soil management treatments on the overall
soil functionality, by comparing measured indicators to the soil property threshold values,
for optimal vine growth; iv) establish a more consistent understanding and use of the terms
health and quality, as understood and used in the general science community, with
particular reference to the public health system. The soil physical, chemical and biological
properties which were selected as indicators of soil health (quality) based on specific criteria
similar to previous work done on the concept. The properties selected include soil texture,
gravimetric water content, bulk density, soil aeration, water aggregate stability, soil pH, EC,
available N,P,K , soil organic matter content, soil microbial biomass, potential mineralizable
nitrogen and soil respiration. The study makes use of methods of analysis previously used
for soil health and soil quality assessments, as well as soil analytical methods as accepted by
experienced soil scientist within the study area. The soil was sampled on three separate
events to depths of 0-200 mm for initial characterization of soil and 0-50 mm to compare
soil health (quality) Between tracks and In tracks of treatment plots. The values obtained for
each property were compared with the optimum for vineyards and ranked accordingly. The
treatment that resulted in the most desirable soil health (quality) was the straw mulch and
perennial cover crop treatments. / AFRIKAANSE OPSOMMING:
Die toestand of gesondheid van natuurlike hulpbronne is aanvaar as `n waardevolle
aanduiding van volhoubare grondgebruik. Die assessering van grond gesondheid (kwaliteit)
is 'n waardevolle hulpmiddel in die bepaling van die volhoubaarheid van grond bestuur
stelsels. Hierdie werkstuk poog om die volhoubaarheid van grond bestuurs praktyke te
evalueer vir wingerde in Robertson, Suid-Afrika wat baseer is op die huidige benadering van
grond gesondheid en kwaliteit. Die tesis dek ook die huidige onsekerhede oor die konsep en
definisies van terme wat gebruik word in die konsep. Die grond bestuur praktyke sluit in 'n
meganiese onkruidbeheer, chemiese onkruidbeheer, jaarlikse toevoeging van `n strooi
deklaag, jaarlikse en meerjarige dekgewas dekgewasse. Die doel van die studie was om (i)
die geskikte grond gesondheid (kwaliteit) indikators vir wingerde in die studie area te
identifiseer, (ii) die grond gesondheid (kwaliteit) indikators vir verskillende bogrond bestuur
praktyke te identifiseer; (iii) die effek van verskillende grond bestuur praktyke op die
algehele grond funksies te evalueer, deur dit te vergelyk met die gemete indikators vir
drempelwaardes vir optimale wingerd groei; iv) 'n meer konsekwente begrip en gebruik van
die terme “gesondheid” en “kwaliteit” vas te stel, soos dit verstaan en gebruik word in die
algemene wetenskaplike gemeenskap, met spesifieke verwysing na die openbare
gesondheidsisteem. Die grond fisiese, chemiese en biologiese eienskappe wat as indikators
van grond gesondheid (kwaliteit) geselekteer was, word gebaseer op spesifieke kriteria
soortgelyk aan dié wat in vorige werk op die konsep gedoen was. Die eienskappe wat
geselekteer is sluit in grondtekstuur, gravimetriese waterinhoud, bulk digtheid, grond
deurlugting, totalle water stabiliteit, grond pH, electriese geleiding, toeganklike N, P, K,
grond organiese materiaal inhoud, grond mikrobiese massa, potensiële mineraliseerbare
stikstof en grond respirasie. Die studie maak gebruik van analitiese metodes wat voorheen
gebruik was vir grond gesondheid en kwaliteit, sowel as die grond analitiese metodes soos
gebruik deur ervare grondkundiges binne die studie gebied. Die grondmonsters was geneem
op drie afsonderlike geleenthede oor dieptes van 0-200 mm vir die aanvanklike
karakterisering van grond en 0-50 mm, om grond gesondheid (kwaliteit) Tussen
trekkerspore en In trekkerspore van die persele te vergelyk. Die waardes verkry vir elke
eienskap was vergelyk met die optimum vir wingerde en verdeel volgens kwaliteit. Die
behandeling wat die mees optimale grond gesondheid (kwaliteit) getoon het, was die strooi
deklaag en meerjarige dekgewas behandelings.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/6544 |
| Date | 03 1900 |
| Creators | Mathys, Ilse Lois |
| Contributors | Rozanov, A., Hoffman, J. E., University of Stellenbosch. Faculty of AgriSciences. Dept. of Soil Science. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 163 p. : ill. |
| Rights | University of Stellenbosch |
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