Agriculture

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http://196.216.167.205/handle/10628/945

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Browsing Agriculture by Author "Smit, G.N."

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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 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.