Thesis (MScAgric)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: The pressure on the world’s natural resources is increased by an expanding global
population. The majority of the growth is expected to take place in Africa and Asia. This
creates the need for sustainable agricultural practices. To sustain food security, the limited
natural resources must be utilised efficiently to optimise agricultural productivity.
Conservation agriculture (CA) is one of the most holistic sustainable agricultural practices
yet. It reduces environmental degradation, and concurrently it could enhance farm
profitability. The practice of CA is able to improve food security while sustaining the
environment for the benefit of future generations of both consumers and producers. A large
proportion of the commercial grain producers in the Western Cape have adopted CA to
varying degrees. A purer form of CA practice is continually pursued to realise its full benefits.
Adoption has taken place in the absence of any policy support framework directed to CA,
and thus, has been market driven. The reasons for and rates of CA adoption in other regions
of the world differed, but was mostly successful, which highlights the driving forces behind
adoption of CA in the Middle Swartland.
The physical/biological benefits of CA are well known. The financial implications of the
various systems within CA, at farm-level are still unknown. This study implements trial data
from Langgewens experimental farm to evaluate the financial implications of various farming
systems over an extended period.
Farm systems are complex, consisting of numerous interrelated components. A whole-farm
budget model is developed within a systems approach to compare various farming systems
designed within CA principles. A trustworthy whole-farm model providing an accurate
representation of a real life farm requires insight across many scientific disciplines. Multidisciplinary
group discussions are used to bridge the gap between scientific knowledge. To
serve as a basis for comparison, the whole-farm model was based on a typical farm within
the Middle Swartland relative homogeneous farming area. Trial data on crop rotations and
tillage systems from Langgewens experimental farm served as starting point for the
research. The data was fitted for use in financial analysis and as input to the typical farm
model. A key role of the inter-disciplinary expert group was to ensure that data and the model
design accurately reflect the underlying physical/biological processes of CA.
The financial evaluation of the various farming systems showed that conventional
agricultural practices of monoculture and deep tillage are financially unsustainable. Farming
systems under conventional tillage returned negative net present values (NPV) and an
internal rate of return on capital investment (IRR) lower than the real interest rate. This
implies that investment in conventional tillage will ultimately lead to financial losses. The
financial benefits of CA are directly related to improved soil health, lower weed and pest
stress and improved yields. The CA farming systems were less susceptible to variations in
external factors, highlighting the resilience of the system that incorporates crop rotation and
no-till. The farming systems operated under conventional practices are expected to be
unsustainable over a long-term period of 20 years. / AFRIKAANSE OPSOMMING: Opsomming
Die druk op die aarde se natuurlike hulpbronne word verhoog deur ʼn groeiende wêreld
populasie. Die meeste van die groei word verwag in Afrika en Asië. Dit skep die nodigheid vir
volhoubare landboupraktyke. Om voedselsekerheid te volhou moet die beperkte natuurlike
hulpbronne doeltreffend benut word om landbouproduksie te optimeer.
Bewaringslandbou is die mees holistiese volhoubare landboupraktyk tot op hede. Dit
verminder omgewingsdegradasie terwyl boerderywinsgewendheid kan verbeter. Die praktyk
van bewaringslandbou is in staat om voedselsekuriteit te verbeter terwyl die omgewing
onderhou word tot voordeel van toekomstige generasies van beide produsente en
verbruikers. ʼn Groot gedeelte van kommersiële graanprodusente in die Wes-Kaap het
bewaringslandbou teen verskillende intensiteit aangeneem. ʼn Suiwer vorm van
bewaringslandbou word deurlopend nagejaag om die volle voordeel daarvan te benut. Die
aanneming van bewaringsboerdery het sonder regeringsbeleid plaasgevind en was dus
markgedrewe. Bewaringsboerdery is in ander wêrelddele vir verskillende redes aangeneem,
maar was meestal suksesvol. Dit beklemtoon die beweegrede vir die aanneming van
bewaringslandbou in die Middel Swartland.
Die fisies/biologiese voordele van bewaringslandbou is wel bekend. Die finansiële
implikasies van verskillende stelsels binne bewaringslandbou op plaasvlak is nog nie bekend
nie. Hierdie studie gebruik proefdata van Langgewensproefplaas om die finansiële
implikasies van verskillende boerderystelsels oor die langtermyn te evalueer.
Boerderystelsels is kompleks en bestaan uit interafhanklike komponente. ʼn Geheelplaas
begrotingsmodel is binne ʼn stelselsraamwerk ontwikkel om verskillende stelsels wat binne
bewaringslandboubeginsels ontwerp is, te evalueer. ʼn Geloofwaardige geheelplaasmodel
wat ʼn akkurate weerspieëling van realiteit verskaf benodig insig van verskeie wetenskaplike
dissiplines. Multidissiplinêre groepbesprekings is gebruik om die gaping tussen die
verskillende dissiplines te oorbrug. Die basis vir vergelyking wat gebruik is, is ʼn tipiese plaas
in die relatief homogene boerderygebied van die Middel Swartland. Proefdata van
verskillende gewasrotasie- en bewerkingstelsels is as die vertrekpunt vir die studie gebruik.
Die data is pasgemaak vir finansiële ontledings en om te dien as inset vir die
geheelplaasmodelle. ʼn Kern rol van die interdissiplinêre ekspert groep was om te verseker
dat die data en die model-ontwerp die onderliggende beginsels van bewaringslandbou
reflekteer.
Die finansiële evaluasie van die verskillende boerderystelsels wys dat konvensionele
landboupraktyke met monokultuur en diepbewerking nie finansieel volhoubaar is nie.
Boerdery stelsels onder konvensionele bewerking genereer ʼn negatiewe netto huidige
waarde en ʼn opbrengs op kapitaal investering wat laer as die inflasie vlak is. Dit beteken dat investering in konvensionele uiteindelik tot finansiële verlies kan lei. Die finansiële voordele
van bewaringslandbou is direk geassosieer met verbeterde grondgesondheid, laer onkruid
en plaag-druk en beter opbrengste. Die bewaringslandbou boerderystelsels is ook minder
blootgestel aan veranderinge in eksterne faktore wat die gehardheid van die stelsels wat
gewas-wisselbou en geenbewerking inkorporeer, beklemtoon. Die boerderystelsel onder
konvensionele praktyke sal na verwagting nie volhoubaar wees oor ʼn langer periode van 20
jaar nie.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/96855 |
| Date | 04 1900 |
| Creators | Knott, Stuart Charles |
| Contributors | Hoffmann, W. H., Labuschagne, J., Strauss, J., Vink, N., Stellenbosch University. Faculty of Agrisciences. Dept. of Agricultural Economics. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 181 pages : illustrations |
| Rights | Stellenbosch University |
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