Bush encroachment poses challenge and opportunity

ELLANIE SMITWINDHOEKBush encroachment is one of the main agricultural challenges in Namibia and is causing massive economic and ecological damage.It is estimated that more than half of the country’s prime rangeland is affected by the excessive expansion of bush at the expense of other plant species, especially grasses.Bush encroachment affects 30 to 45 million hectares, which is more than a third of Namibia’s total landOpportunities for engineers, entrepreneurs and research on biomass utilisation were shared at an event hosted by the Namibian University of Science and Technology (Nust) in Windhoek on Friday.Researchers presented findings of a three-year project exploring sustainable biomass utilisation.The Nust project, titled Biomass Utilisation by Sustainable Harvest (BUSH), ran from November 2018 to July 2021.This project was financed by the GIZ project on Bush Control and Biomass Utilisation (BCBU) to the tune of N$5.3 million.Opportunity“While bush encroachment constitutes an immense challenge for Namibia, it also opens significant commercial, as well as unprecedented socio-economic and ecological opportunities,” said Professor Hannes van der Walt, dean of the Faculty of Engineering.The most significant consequences of bush encroachment are reduced carrying capacity of affected rangelands, groundwater recharge and biodiversity loss, increased atmospheric carbon dioxide levels and desertification.Over the past two decades, the Namibian government has been implementing activities tailored to combat bush encroachment.Job creationEnvironmental commissioner Timoteus Mufeti said as the bush biomass sector grows, they have to ensure that scientific research capacities are built that can support that growth.“The Nust BUSH project showed that the development of innovative technology in the field of bush biomass utilisation can come from within Namibia for a wide range of value chains that can be taken up now by the private sector to make an economically feasible case,” he said.Bush thinning can translate to a huge potential for job creation, if the harvesting of biomass is done with small, effective, manual bush thinning tools, rather than with large expensive machines. Consequently, the sub-project ‘Optimisation of Manual Bush Control Methods and Technologies’ has developed a prototype for a trolley-mounted hydraulic cutter.Evert Strydom, principal investigator of the BUSH project, suggested further research on this cutter so that Namibia will have its own locally produced machinery, developed for its specific conditions, by the country’s own engineers.“We want it to be easy to manufacture and accessible to everyone.”BiocharA sub-project on biochar production, processing and testing, led by Dr Ibo Zimmermann, Associate Professor in the Faculty of Natural Resources and Spatial Sciences, looked at how biochar can create income for farmers and entrepreneurs as well as benefits for crop and rangelands.The project developed prototypes for stoves that heat water or allow cooking while producing biochar. Ultimately, this can make biochar production accessible to many Namibians.Biochar can also be instrumental in rangeland restoration and horticulture production. Adding biochar to soils can create housing for beneficial microbes, return minerals and increase water-holding capacity. However, the research showed that these benefits will only be realised in the long term.Power generationFurthermore, a techno-economic assessment of bio-gasification technologies based on encroacher bush was conducted.This technology is highly relevant for electrification of off-grid communities and businesses such as hospitality operations. With gasification, Namibia can develop a powerful renewable energy source.Based on the assessment of the technology for producing animal feed from bush, project findings can help farmers in their decision of purchasing the appropriate machinery for the production of bush feed.Research finding showed that Namibian conditions are very challenging and that many imported machines struggle.It is important for farmers to realise that the costs of running imported machines will be considerably higher than what is noted in the manufacturer’s specifications.One sub-project looked into the opportunity of producing wood-plastic composites. These are mixtures of thermoplastic polymers and wood pulp.They can be manufactured in different colours, shapes and sizes and can be used for a wide variety of applications, including windows, door frames, fences, landscaping timbers and furniture.

Bush encroachment poses challenge and opportunity

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Namibian Sun 2025-05-02

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Bush encroachment poses challenge and opportunity

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Namibian Sun 2025-05-02

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