Browsing by Author "Zimmermann, Ibo"

Now showing 1 - 12 of 12
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    Case study of adaptive rangeland management by an innovative Kalahari farmer.
    (2008) Zimmermann, Ibo; Joubert, David F.; Smit, G.N.
    Scientists can learn a great deal from innovative farmers who apply adaptive management principles based on experience gained over decades. This paper records 31 observations that a farmer, Jan Labuschagne, made on his farm to the south of Gobabis. The observations relate to aspects such as animal behaviour and performance, animal trampling, and applications of grazing and fire. They are tabulated together with their possible explanations and their management applications. The conceptual model the farmer has built to aid his understanding and decision making is also shown as a diagram and explained. Of critical importance is the strategic timing of management interventions on different parts of the farm in relation to rainfall events, texture and organic content of the soil and maturity of the vegetation. Data are presented to support some of the observations
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    A crude quantification of wood that is and can be harvested from bush thickening species in Namibia.
    (Namibia, Ministry of Environment and Tourism, 2002) Zimmermann, Ibo; Joubert, David F.
    The increasing rate at which thickening bushes are being harvested in Namibia requires better information on the availability and sustainability of the resource, in order to improve management. Two sources of data from the literature were combined to give a rough approximation of the standing biomass of wood of appropriate size for charcoal production, in each of nine bush-thickened zones. The overall estimate came to roughly 135 million tons of dry wood in about 260 000 square kilometres of Namibia, or an average of just over 5 t/ha. The legal commercial harvest for the 1999/2000 financial year came to the equivalent of just under 0.2 million tons of dry wood. Interviews with ten charcoal producers, and field data gathered at one site, suggest that harvesting could take place at intervals of roughly 20 years, provided that harvesting is selective and leaves sufficient bushes of different size classes for regeneration. However, it is likely that subsequent harvests would be lower and more difficult to obtain. Previously chopped bushes could then only be re-harvested on every third or fourth cycle, preferably after being pruned to maintain a more appropriate growth form, which is easier to harvest and more conducive to grass growth.
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    Degradation gradient as a basis for monitoring the ephemeral Omatako floodplains of central Namibia.
    (Global Wetlands, 2003) Zimmermann, Ibo
    A group of Herero cattle farmers initiated a community grazing trial within a floodplain of the ephemeral Omatako River in central Namibia. A degradation model was constructed from measurements of various characteristics, for determining changes in wetland condition. Species data for Canonical Correspondence Analysis (CANOCO) came from the nearest perennial grass, if present within 5m of the sample point, otherwise from the nearest annual grass. The first ordination axis indicates a degradation gradient, with perennial grass species towards one extreme and annual grasses towards the other. The second axis appears to reflect a moisture gradient, although it was not measured.
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    The effect of a prescribed burn, followed up with browsing pressure, on rangeland condition in the mountain savanna and karstveld of Namibia.
    (DINTERIA, 2002) Zimmermann, Ibo; Mwazi, Fidelis N.
    Measurements were taken before and after the application of a prescribed burn, aimed at controlling bush thickening, on a commercial farm in the Mountain savanna and Karstveld of Namibia. The high fuel load, due to high rainfall during the previous season, resulted in an intense fire that caused considerable top kill of bushes. However, the bushes, dominated by Dichrostachys cinerea, resprouted at varying time intervals after the fire, mostly from the ground level. The occasional goat browsing pressure that was subsequently applied was insufficient to keep the majority of bushes under control. Hence browsing pressure would need to be applied more frequently and over a longer time period after a fire, in order to keep more of the bush regrowth under control. The goats also grazed significantly on the regrowth from perennial grasses. Therefore the browsing pressure should not be excessive, as the goats also threaten the perennial grasses.
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    Innovation and entrepreneurship through business incubation - Developing a business plan for Aunt Diana's EM Derivatives, a start-up small and medium enterprise (SME).
    (NUST & Tshwane University of Technology, South Africa., 2007) Armah, P.; Zimmermann, Ibo; Kumbuli, R.
    Aunt Diana's EM Derivatives is a start-up SME (small and medium sized enterprise) business that has benefited the targeted support services provided by NUST. These services have been orchestrated by an incubator management team from the Department of Agriculture with the goal of empowering a former student to start a business that produces and markets derivatives of Effective Microorganisms (EM) in Namibia. The company has the potential of commercialising EM derivatives, providing Namibians with an environmentally friendly alternative to chemical products and strengthening Namibia's economy. Critical to the creation of Aunt Diana's EM Derivatives is the continuous assistance by the support team in the provision of a business plan, management guidance and technical assistance tailored to the young entrepreneur and owner of the company. Using Aunt Diana's EM Derivatives as a case study, this paper discusses the process of developing the company's business plan and the unique incubating services that NUST can provide to create the right environment for nurturing young entrepreneurs to create start-up companies.
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    Joint action research at Kwandu Conservancy between community members and students of the Agriculture Diploma program.
    (NUST, School of Natural Resources and Tourism., 2006) Zimmermann, Ibo
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    Joint action research at Queen Sofia Resettlement Project between community members and students of the Agriculture Diploma Program.
    (NUST, School of Natural Resources and Tourism., 2003) Zimmermann, Ibo; Mbai, Salomo; Kafidi, Lucia; Meroro, Alex
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    Joint action research at Vasdraai Farm between resettled farmers and students of the Agriculture program.
    (Department of Agriculture; NUST, 2010) Zimmermann, Ibo; Shiimi, Theofilus; Zaire, Helga; Kafidi, Lucia; Mbai, Salomo
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    Overview of a variety of trials on agricultural applications of effective microorganisms (EM).
    (2008) Zimmermann, Ibo; Kamukuenjandje, Richard
    Effective Microorganisms (EM) is a commercially available liquid containing a variety of lactic acid bacteria, yeasts and phototrophic bacteria. These organisms create conditions which favour mutual support and enable them to outcompete harmful pathogens, while producing useful substances such as vitamins, enzymes, hormones, amino acids and anti-oxidants that create a reducing environment. Various EM agricultural application trials were run, mostly in partnership with farmers. The diverse applications included the following: improving soil conditions for better plant growth, treating waste water, controlling pests and diseases, improving animal growth, enhancing compost production and extending the shelf life of harvested crops. Generally EM appears to give the best results in situations where the natural balance of microorganisms has been severely disrupted or where agricultural inputs are in short supply. In situations where natural microorganism populations are reasonably intact, or where a balanced supply of inputs is available, the addition of EM does not seem to make a significant difference.
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    The potential impacts of wood harvesting of bush thickening species on biodiversity and ecological processes.
    (Namibia, Ministry of Environment and Tourism, 2002) Joubert, David F.; Zimmermann, Ibo
    Studies of the effects of bush clearing have mostly focussed on economic issues such as production. In this paper, biodiversity and ecological effects of bush clearing were investigated, largely through a literature survey. Vertebrate and plant taxa were focussed upon. Two future scenarios were discussed. The first scenario was that future wood harvesting would follow Forestry Stewardship Council Principles and Forestry Guidelines. The second scenario was that demand exceeded supply and that sound sustainable principles would be abandoned in certain areas, in order to chase demand. In the first scenario, biodiversity would be improved, as would ecological processes. In the second scenario, arboreal species, including cavity users, and species requiring microhabitats and shelter would be badly affected, with local extinctions of these species likely. Management recommendations are provided. Biodiversity research should be viewed as a priority, in order to better understand the effects of different wood harvesting management strategies.
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    A problem tree to diagnose problem bush.
    (2008) Zimmermann, Ibo; Joubert, David F.; Smit, G.N.
    The term “problem tree” refers to a conceptual model used as a diagnostic tool to analyse a sequence of events that leads to a problem (such as bush encroachment in rangelands). A problem tree is useful because the consequences of different interventions can be visualised and understood more easily in diagrammatic form, thereby guiding management decisions regarding the problem. A problem tree was constructed to show multiple causes of bush encroachment. It was generalised by considering many possible causes, and not only those applying to particular areas of encroachment or specific species of bush. If the problem tree is to be useful in decision-making, one needs to determine which of the multiple pathways are of greater significance in any particular situation. Management decisions are bound to be more effective in the long run if they address causes higher up in the tree and closer to the root causes, than the proximate causes or symptoms at the bottom of the tree.