Browsing by Author "Piesse, Jenifer"

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    The effect of predator culling on livestock losses: Ceres, South Africa, 1979 - 1987
    (2013) Conradie, Beatrice; Piesse, Jenifer
    Caracals (Caracal caracal) and leopards (Panthera pardus) are perennial problems for sheep farmers on the southern fringe of the arid Karoo. In the past, farmers responded to the conflict with blanket culling of predators, a strategy which ecologists understand to be harmful. This paper investigated the ability of blanket predator culling to reduce livestock losses. It found the probability of livestock losses to be a function of the number of caracals, leopards, vagrant dogs (Canis familiaris) and other wildlife culled during the previous year, as well as the previous year’s trapper effort, the farm’s remoteness and three years’ worth of rainfall. Other unobserved farm characteristics did not systematically affect losses. Culling an additional caracal or leopard was estimated to increase future livestock losses by 5.7% and 27.2% respectively, while culling a vagrant dog was estimated to reduce the likelihood of future losses by 9.5%. Both trapper effort and remoteness increased the probability of livestock losses. The current and previous years’ rainfall decreased the likelihood of future losses, while rainfall from two years prior was positively correlated with future losses. These results are important because they describe general culling effectiveness under a variety of management conditions over a period long enough to allow for adjustment to culling.
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    Explaining declining agricultural total factor productivity in the Karoo districts of the Western Cape, 1952 to 2002
    (Taylor and Francis online, 2013) Conradie, Beatrice; Winter, Kevin; Piesse, Jenifer; Thirtle, Colin; Vink, Nick
    Conradie et al. (2009a and 2009b) identified the Central Karoo as the worst performing area in the Western Cape, but left the reasons for the region's declining total factor productivity (TFP) unexplained. The current paper uses a combination of literature review and analysis of anecdotal evidence to evaluate a set of hypothetical reasons for the decline. The world wool price clearly affected farm-level profitability, putting up to 50% of sheep farms out of business in some parts of the Central Karoo. If census data were properly collected, this in itself should not have affected TFP. The evidence for overgrazing and increasingly ineffective predator control was less convincing. For example, there is no conclusive evidence yet on whether game and lifestyle farms exert any negative externalities on remaining sheep operations. The cost-price squeeze resulting from falling prices and rising input costs has led to an extension of production systems and poor maintenance which will no doubt lead to a further decline in productivity. We concluded that the rate at which the Central Karoo is shedding sheep farming, and the reasons for and effects of it, should be investigated further.
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    Productivity benchmarking of free-range sheep operations : technical efficiency, correlates of productivity and dominant technology variants for Laingsburg, South Africa
    (2014-08-05) Conradie, Beatrice; Piesse, Jenifer
    Data envelopment analysis (DEA) was used to benchmark extensive sheep operations in Laingsburg in the Central Karoo, South Africa, with data from the 2012 production season. An input oriented variable returns to scale frontier identified twelve efficient firms, and nine more that are technically efficient but not scale efficient. The top third’s overall efficiency score was 0.999. For the bottom third the average efficiency score was just 0.346, which indicates that there is substantial room for improvement amongst bottom third producers in this production system. Overall efficiency was correlated with stocking density, flock size, unit production cost and profitability, cumulative family experience of farming and the use of family labour, but not with farm size, breed choice or any proxy for individual experience or ability. Predation rates in particular were uncorrelated with productivity scores and reproductive performance was only weakly correlated with it. While most farms could theoretically improve their efficiency by intensifying their operations, a closer analysis of best practice firms revealed a spectrum of optimal intensities including the possibility of restoring rangelands by deliberate understocking. Grazing strategy and the degree of labour self-sufficiency emerged as the key determinants of optimal intensity.
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    A study of group dynamics in the South African dairy industry: A sequential Malmquist approach
    (2015-08) van Niekerk, Hugh; Conradie, Beatrice; Piesse, Jenifer
    This study presents a sequential Malmquist index for twenty members of an Eastern Cape dairy study group for the period 2010 to 2013. On average these farms were at efficiency levels of 95% and more during this period. The group’s mean technical progress was 11% per year. This resulted in productivity growth of almost 14% per year. However, these estimates are probably inflated as they were obtained with the combination of a small dataset and a large model. The group is a success because it transfers knowledge and enables innovation. We found weak support for the belief that it is beneficial to operate mixed breed herds and showed that less intensively managed or smaller herds did better than larger herds or herds managed for the maximum amount of milk per cow. Productivity growth was positively correlated with various proxies for knowledge. It increased with self-sufficiency in hay production and expenditure on concentrates, and was inversely related to the unit hay cost. Rainfall was positively correlated with self-sufficiency but not with unit hay cost or productivity. To conclude: study groups could a useful tool for driving innovation in any industry. Innovation can happen quickly but is complex, and therefore it helps to have a single metric of progress. Good data are needed to develop accurate measures of innovation, but if available could be the difference between noting a potential disaster in time and failing altogether.
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    Total factor productivity of urban agriculture on the urban periphery of Cape Town
    (2015) Dyer, Martin; Mills, Richard; Conradie, Beatrice; Piesse, Jenifer
    This paper investigates the efficiency relationships between inputs and outputs of urban micro-farms in two of Cape Town’s townships: Nyanga and Khayelitsha. The inputs in this study were land, labour, seeds and seedlings, compost and farmer experience. Data Envelopment Analysis (DEA) was applied to 33 producers supplying a social enterprise box scheme, thereby generating individual efficiency measures relative to best practice. The DEA results revealed an average level of overall, technical and scale efficiency of 72.4%, 79.7% and 90.6% respectively. Overall efficiency was negatively correlated with land holdings and the use of compost and seedlings. This is supported by the finding that the nine best-practice farms were characterised by a smaller scale of production, indicating that efficiency losses are experienced as greater quantities of inputs are used. In terms of area differences, Nyanga farms exhibit significantly higher technical efficiency, whereas farms in Khayelitsha are more scale efficient. Standardised input and output data show both the expenditure on compost and seed to be profitable, but we failed to show that mulching or operator experience increases profitability. Fully efficient farms are R2,600 per plot more profitable than inefficient farms while farms that need a windbreak earn R700 less per plot per season than more sheltered operations. These results are the first of their kind for South Africa and lay the foundation for more effective extension to the sector.