Thesis (PhD(Agric) (Agricultural Economics))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: This dissertation is an analysis of dairy production in the Midlands district of KwaZulu-Natal.
The analysis of agricultural production generally ignores undesirable outputs that are
produced alongside desirable outputs. This research attempted to integrate a model of nitrate
leaching from dairy production into a multiple input/output representation of the production
technology, together with the analysis of technical efficiency. Estimation of both technical
efficiency and environmental efficiency were done following the parametric econometric
stochastic frontier (SFA) and the nonparametric mathematical programming data
envelopment analysis (DEA) approaches.
The study used unbalanced panel data from 37 individual highly specialized dairy farms for
the period 2000 to 2007 and totals to 2130 observations. Production functions for the three
outputs; milk, animals and farm produced feed, were fitted as a simultaneous system to model
the farms’ production activities for the econometric SFA estimation of technical efficiency. A
single equation reduced form was fitted as a frontier to allow for the estimation of the relative
efficiencies of the individual farms. The results showed that with data this detailed it was
possible to refine the model until it fits very tightly. Indeed, in the gross output model that
includes cows, there was nothing left to call inefficiency and what was clearly a frontier
becomes a mean response function. Technical efficiency was further calculated using the
nonparametric DEA approach using the same dataset.
The estimation of environmental efficiency was done using both SFA and DEA approaches.
Undesirable emissions of nitrate were represented within the models by calculating nitrogen
surplus (kg/ha) for each farm. This nitrogen surplus value was based on the intensity of the
use of nitrogen containing inputs and the nitrogen content of marketable products specific
information and from farm data which were used to calculate a farm nitrogen balance. The
stochastic estimation of environmental efficiency used the same data that were used for the
estimation of technical efficiency. However, for the DEA calculation of environmental
efficiency, a balanced cross-section dataset for 34 farms participating in a pasture-utilization
programme was used. This dataset was used because it had quantities of nitrogen fertilizer
and other nitrogen containing inputs.
Results indicate that there was minimal “over-usage” (over production) of milk thus reducing
milk output alone will not lead to improved environmental efficiency. Farm size, herd size,
and quantity of nitrogen fertilizer applied, present the best scope of reducing nitrogen surplus
thus improving environmental efficiency of the dairy farms. Reducing imported feed by
relying more on home grown feed can also help reduce nitrogen surplus. This is feasible
because dairy farmers in the KwaZulu-Natal Midlands can produce most of the feed on farm.
In summary, to obtain environmental efficiency milk production would have to be reduced by
80 litres per hectare; farm size by 73.69 ha; herd size by 33 cows, nitrogen fertilizer
application by 74.3 kilograms per hectare; and imported feed by 13.4 kilograms of dry matter
per hectare. The adjustments that would be required if environmentally inefficient farms were
to adopt best practice technology and move towards their environmental production frontiers
indicate that the production of pollutants (nitrogen surplus) could be reduced at negligible
cost to milk production. The positive correlation between technical and environmental
efficiencies indicates that improving environmental efficiency could be associated with
improvements in technical efficiency. Thus, policies aimed at improving both efficiencies
could have substantial rewards. / AFRIKAANSE OPSOMMING: In hierdie tesis word suiwelproduksie in die Middellande van KwaZulu-Natal van nader
beskou. Met die ontleding van landbouproduksie, word ongewenste uitsette wat saam met
gewenste uitsette geproduseer word, gewoonlik oor die hoof gesien. Hierdie navorsing poog
om ’n model van nitraatvrylating uit suiwelproduksie in ’n veelvuldige inset/uitset
verteenwoordiging van die produksietegnologie, te integreer by die analise van tegniese
doeltreffendheid. In opvolging van die benaderings tot die parametriese ekonometriese
stogastiese front (SFA) en die omvattingsanalise ten opsigte van die nie-parametriese
matematiese programmeringsdata, is beramings van sowel tegniese as omgewings
doeltreffendheid gedoen.
In die studie is gebruik gemaak van paneeldata van 37 individuele hoogs gespesialiseerde
melkplase vir die tydperk 2000 tot 2007, wat altesaam 2130 waarnemings beloop.
Produksiewerksaamhede vir die drie uitsette; melkproduksie en diere- en plaasgeproduseerde
voer, is as ’n gelyklopende stelsel ingepas om die plase se produksiewerksaamhede vir die
ekonometriese SFA-beramings van tegniese doeltreffendheid weer te gee. ’n Enkele vorm om
gelykmaking te verminder is daargestel as ’n front vir die beraming van die relatiewe
doeltreffendhede van die individuele plase. Die resultate het bewys dat data van hierdie
omvang dit moontlik maak om die model sodanig te verfyn dat dit net-net inpas. By die bruto
uitset-model waarby koeie ingesluit is, was daar inderdaad niks wat op ondoeltreffendheid
gedui het nie en wat eers ’n duidelike front was, het ’n betekenisvolle responsfunksie geword.
Voorts is tegniese doeltreffendheid bereken deur aanwending van die nie-parametriese DEAbenadering,
deur gebruik te maak van dieselfde datastel.
Die beraming van omgewingsdoeltreffendheid is gedoen deur gebruikmaking van sowel
SFA- as DEA-benaderings. Ongewenste nitraatvrylatings is in die modelle gevind deur die
stikstofsurplus vir elke plaas te bereken (kg/ha) Die waarde van hierdie stikstofsurplus is
gebaseer op die intensiteit van die gebruik van stikstofbevattende insette en bepaalde inligting
oor die stikstof-inhoud van bemarkbare produkte, sowel as van plaas data, wat gebruik is om
’n stikstofbalans vir die plaas te bereken. Dieselfde data wat aangewend is vir die beraming
van tegniese doeltreffendheid, is gebruik om die stogastiese beraming van
omgewingsdoeltreffendheid te bepaal. Vir die DEA-berekening van omgewingsxii
doeltreffendheid, is egter ’n gebalanseerde kruisseksie datastel gebruik vir 34 plase wat aan
’n weidingsbenuttings-program deelgeneem het. Die bepaalde datastel is gebruik omdat dit
dosisse stikstofbemestingstof en ander stikstofbevattende insette bevat het.
Resultate het op minimale “oorgebruik” (oorproduksie) van melk gedui en daarom sal die
vermindering van slegs die melkuitset nie lei tot verbeterde omgewingsdoeltreffendheid nie.
Plaasgrootte, kuddegrootte en die dosis stikstof wat toegedien is, verskaf die beste beeld van
verminderde stikstofsurplus, wat dus tot verbeterde omgewingsdoeltreffendheid op melkplase
lei. Die vermindering van ingevoerde voer deur meer op plaasgeproduseerde voer staat te
maak, kan ook meewerk om stikstofsurplus te laat daal. Dit kan gedoen word omdat
melkboere in die Middellande van KwaZulu-Natal die meeste van die voer op die plaas kan
produseer.
Ter samevatting kan gesê word dat om omgewingsdoeltreffendheid te bereik moet
melkproduksie met 80 liter per hektaar verminder word, plaasgrootte met 73.69 ha,
kuddegrootte met 33 koeie, stikstofbemestingtoediening met 74.3 kilogram per hektaar en
ingevoerde voer met 13.4 kilogram droë materiaal per hektaar. Die aanpassings wat nodig sal
wees indien omgewingsdoeltreffende plase beste praktyk-tegnologie sou aanvaar en sou
aanbeweeg na hulle omgewingsproduksiefronte, dui daarop dat die produksie van
besoedelende stowwe (stikstofsurplus) verminder kan word teen geringe koste aan
melkproduksie. Die positiewe verband tussen tegniese en omgewingsdoeltreffendhede, dui
daarop dat die verbetering van omgewingsdoeltreffendheid, in verband gebring kan word met
verbeterings in tegniese doeltreffendheid. Beleid wat op verbetering van beide
doeltreffendhede gemik is, kan daarom aanmerklike voordele inhou.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/6768 |
| Date | 03 1900 |
| Creators | Mkhabela, Thulasizwe |
| Contributors | Thirtle, C., Piesse, J., Vink, N., University of Stellenbosch. Faculty of AgriSciences. Dept. of Agricultural Economics. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 212 p. : ill., maps |
| Rights | University of Stellenbosch |
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