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November/December 2023 | Muedanyi Ramantswana & Henny Zitha

Optimising Modern Silviculture – 2023 Webinar



On the 18th of October 2023, the Nelson Mandela University Forestry Department hosted its fourth webinar under the theme “Optimising Modern Silviculture." Sustainability in forestry can be facilitated by introducing new technologies and ensuring the efficiencies of existing modern silviculture systems are optimised. The webinar theme focused on exploring how new and existing technologies can be used optimally to perform various silviculture activities. The webinar covered some of the main silviculture strategies and technologies that are currently in use and that will be used in the future, locally and internationally. The webinar was attended “live” by 290 attendees (professionals and students). The attendees were from neighbouring countries such as Zimbabwe, Swaziland, Ghana, Uganda, and several others. Internationally the attendees the webinar was attended by people from South America, Europe, and Asia. A total of eight presentations were delivered by experts in various fields of silviculture technology in South Africa, Brazil, Finland, and Netherlands. A summary of all the presentations is provided below.

Pathways to modernization
Ms Zimbili Sibiya from the University of Stellenbosch presented about the “Pathways to Modernization: bringing research technology and stakeholder needs in silviculture.” Her presentation looked at the drivers of modernization and touched on the perspectives of various stakeholders. She further looked at the progress in understanding the strategic alignment to modernization. She then presented a study looking at “Bipolar surface electromyography sensors (muscle activation) and “Internal and magnetic measurement unit sensors for kinematics” when using manual equipment (Pickaxe, crowbar, and single-handed hoe) to execute pitting operations. She outlined interesting results that indicated that:
• There was no bilateral muscle activation and extreme flexion of lower spine when the three equipment were used,
• The dominant side gets tired when the is a high load,
• All equipment influenced the upper traps and;
• When using the crowbar there was less lumber muscle activation on the operator.

Residue management methods
Mr Henny Zitha from the Nelson Mandela University presented on the “Performance and effects of Pine Harvesting Residue Treatment Methods in South Africa” which is study that looked at three residue management methods, namely manual (broadcasting), semi-mechanised (broadcasting + tractor mulching) and fully mechanised (purpose-built mulcher). This study came about due to the lack of information relating to modern residue management methods such as mechanised mulching. His presentation looked at the three residue management methods in terms of productivity, work quality, costs, survival, and growth. The results found that the fully mechanised method was the most productive and had the best work quality, however it was expensive and obtained the highest mortality. While the manual and semi-mechanised methods were less productive and achieved the least work quality however, they were less expensive compared to the fully mechanised methods with an average mortality.

Advanced weeding operations
Mr Mbhekiseni Nsele from Amahlathi Ethu trading presented on “Advanced weeding with the Troner tractor sprayer.” His presentation focused on weeding using a Troner tractor sprayer. In his presentation he touched on the system’s application, productivity, implementation, efficiency and how the computer and GPS system helps improve weeding efficiency and accuracy. He gave an overview of the results, comparing the productivity of the Troner tractor boom sprayers (4.5ha/PMH) with other weeding sprayers such as the Sam sprayer (1.5ha/PMH), ZAF boom sprayer (2ha/PMH), Jactor sprayer (2.3ha/PMH) and drone sprayer (2.2ha/PMH). Finally, he looked at the challenges and opportunities of using the Troner tractor sprayer in forestry.

Mechanised planting in Swaziland
Mr Binda Zwane from connexions investments in Swaziland presented on the “early lessons in mechanised planting in Swaziland.” He began his presentation by providing reasons why mechanize planting was considered in Swaziland by looking at the problems, causes and benefits of mechanised planting. He further described the configuration of the Bell excavator-based machine with the ASP 360 Risutec planting head looking at its functions in terms of marking, slash removal, pitting, irrigation, fertilizing and pesticides application. Thereafter, he presented about the machine in terms of strategic benefits, team composition per month, seedling survival analysis (78-90%), productivity (150-250 tree per hour), seedling tray specifications e.g., polystyrene, Unigrow, Sappi49er), seedling quality factors and growing medium suitability when using this machine. He concluded by providing an overview of the challenges and opportunities including the working conditions in Eswatini.

Nursery automation
Mr Joep Hendricks from the ISO group presented on the “Plantation forestry nursery automation and robotics.” His presentation focused on key breeding, propagation and cultivation processes which looked at the cutting planting, bulb planting, grafting, grading, and sorting, plant data generator, DNA sampling and plug planting – these are all customised solutions, and which optimize the workflow in a nursery. He touched on the new forestry cutting planter modified to adhere to plantation forestry specifications for nursery application with the provisional capacity of 3 400 cuttings per hour. Furthermore, he gave an overview of the cutting planter 4000, 2.0 which ensures uniform cutting material and ISO grade 8000 used for grading and sorting. He concluded by giving guidelines on the conditions for a successful introduction of this robots in forestry nurseries.

Digitalising regeneration operations
Mr Henrik Janer from Risutec presented on “Digitalising regeneration operations,” giving an overview of reasons to digitalise regeneration operations as being:
• Loss of too much money due to mortality
• High staff turnover
• Risk and cost of compliance
• Increased vulnerabilities from heat, pests, and diseases
 He further presented on waste because of poor planning (informational), growing forests (operational), focusing on monocultural Myopia (biological) and Risutec’s precision forestry offering. In each of these aspects he touched on their significance in forestry, and he gave examples. Finally, he described Risutec’s stand-alone precision forestry offering which has a forest builder service for digital workorder management, ASTA precision forestry toolkit, and the data forest for secure integration to forest ERP and GIS platforms and reforesting for heterogeneity.

Mechanised planting in Brazil
Mr Christer Larsson from Plantma Forestry AB presented on “Mechanised planting on diverse conditions using the PlantMax.” His presentation started by giving a brief background of Plantma forestry and touched on the planting methods that exist from manual planting using the planting tubes to planting robots with no human intervention. He then presented about the new development which is the PlantMax X2. He then touched on machine flexibility being a key for a successful operation looking at the seedlings, ground conditions and the planting spot. He also presented on the maximised advantages of the PlantMax being:
• Simultaneous ground preparation and planting
• Consistency and power
• Possibility of fertilizing, water and adding other additives
• Data collection
• Technology developments – the use of AI
According to Christer, when tested the PlantMax could handle with ease slopes of 35% and can plant up to 3000 seedling per hour on continuous planting. Finally, he explained about the PlantMax planting unit configuration and the attachments (MidiFlex scarifier, ripper and the seedling conveyer).

Last initiatives and updates of mechanised planting in Brazil
Mr Cassio Gomez form Eldorado Brazil presented on “Last initiatives and updates of mechanised planting in Brazil.” His presentation gave an introduction on the Brazilian forestry sector, thereafter he gave an overview of the planting machines and development stages and described the challenges of various planting machines. In his introduction he looked at an older planting concept that was used but discontinued due to ergonomics and safety. Thereafter, he described newer planting machines such as the Komatsu triple planter D61 – suitable for flat conditions, Single head (P12b) and Double head (P22) Bracke/Komatsu planters – suitable to work on 35 and 20 degrees slopes respectively, PlantMax and the Risutec planting machines that are available for sale on markets. He further touched on planting machines under development by John Deere, Novelquip & Ponsse, Forest bot, CMAK, Risutec two row planter and 8D planter which they are running field test on. On the challenges he explained the following:
• Ripping variation types and spot ripping/pitting
• Multiple guide variance
• Amount of drowned stem tolerance
• Site condition and seedling quality
• Company needs in terms of machine specifications.
Next year’s event date is yet to be announced.
For more information about the event and to contribute please contact the facilitator Dr Ramantswana at