By Joy Crane
More than 300 people from South Africa, Brazil, New Zealand, Kenya, Australia, Indonesia and Mozambique attended Forsilvitech’s latest webinar on “Enabling Modernisation in Silviculture.”
The webinars provide information on modern technologies that can help improve and refine silvicultural practices.
After a brief welcome by Dr Kaluke Mawila, the Nelson Mandela University (NMU) George campus principal, the webinar facilitator Dr Muedanyi Ramantswana got down to business.
Ramantswana said technologies are emerging that are changing silviculture. Foresters are rapidly needing different types and levels of knowledge and skills to understand new technology platforms.
Automation, photometric, Lidar, geographical information systems (GIS), remote sensing and uncrewed aerial vehicles (UAVs) are increasing silviculture’s accuracy, safety and efficiency.
“Although there is a need for investment in modern silviculture, we must bear in mind that technologies don’t solve everything; we also need people to manage it,” he stated.
NURSERY 4.0
Damien Naidu, nursery technology programme leader at the Sappi Research Centre, said the purpose of a nursery is to ensure that plants with the highest possible chance of survival are supplied to foresters. High-quality planting stock leads to optimum stocking and superior growth.
Naidu described the three pillars of nursery efficiency: the “golden goose” mother plant hedges that produce the “golden egg” cuttings and rooting. He explained how biodegradable paper pots produce superior seedlings with root systems that capture the planting pit quickly and survive better in the field.
“Plug extraction is critical. Unskilled and high turnover labour can be rough on extraction from plastic inserts, resulting in root deformation. Planting the ellepot paper pot seedlings is easier, quicker and eliminates the sorting, cleaning and packing of the non-biodegradable plastic inserts,” Naidu said.
“Better survival results in better utilisation of high-value planting stock and timber. Seedlings and cuttings must be dispatched within certain specifications for their species, propagation method and container size and type.”
PQI, RPQ and QR
Naidu explained Sappi’s Plant Quality Index (PQI), where the nursery uses a fully integrated digital system and a LoRaWAN-like (long-range wide-area network) with multiple cheap sensors to increase efficiencies and automate processes.
It measures chemical, physical or biological parameters and allocates scores to infer physiological status. The data is used to manage water, irrigation moisture, stock inventory and assets.
The Rapid Plant Quality Assessment (RPQ) uses an iPhone camera and python scripting to automate plant height measurements within a nursery tray. The data provides information to develop growth curves and assist with automated measurement of plant quality. A QR code accompanies every batch of seedlings from the nursery to the plantation.
Naidu commented that the nursery systems provide a way to predict good survival and growth after planting under normal conditions. Still, it isn’t easy to correlate the data to predict survival to rotation age. “There are too many factors to consider. Tree survival includes the interaction between genetics, the environment, climate, site quality, nutrition and stand competition.”
STEEP SLOPE SILVICULTURE
Forestry graduate and contractor Dumisani Shweni of New Forestry Solutions shared information on mechanised planting on steep terrain. The company is working for Mondi in the Umzimkhulu area in southern KwaZulu-Natal.
“The terrain is steep and rocky. We had to adapt our operations to meet the site and Mondi’s health and safety, ergonomics and productivity requirements by modernising our steep terrain silviculture systems,” Shweni said.
Pre-planting
The first step was to draw up the silviculture plan to match the technology with the site. Aerial photos taken by a drone were used for mapping the block and assessing the risk.
A DJI-T30-Agras drone executed pre-planting spraying. “Drone data is safe to acquire, accurate, and cost-effective. You cannot compare the information with that gathered by people on the ground,” commented Shweni. He listed the advantages of drone-based aerial spraying:
- No slope limitations
- Cost-effective
- Accurate data
- More productive compared with manual methods
- It covers about 35 hectares per shift, making it possible to operate three daily shifts.
Pitting
Pitting was done without marking using Novelquip’s dozer-mounted single-head MPAT pitting machine. It worked two shifts a day, at two hours per hectare, compared with five person-days per hectare.
“People only enter the plantation area when planting, using selective chemicals and blanking. The drone limits people’s exposure”.
Planting
“Our wheeled tractor could only work up to 15% gradient while the dozer planter is a tracked hydrostatic driven machine that can plant on slopes up to 35%.” The dozer has a carrying capacity of 1300 litres of hydrogel mix and a centrifugal pump to mix the hydrogel.
Eight people are needed for planting. Four people do the planting, two replenish the seedlings, one works at the sorting station, and one is the dozer operator. An average of four hectares is planted in an eight-hour shift.
Although mechanical pitting replaces about 20 people, it saves them from back-breaking work. Safety is still a priority because, in high residue areas, there is a risk of logs hitting people walking behind the planter. It is better for people to work on a burnt site with 10cm high stumps. If this is not possible, then a de-stumper is used. The drone helps us plan the harvesting system.
We are considering attaching the Wasser high-pressure pitting, planting and fertiliser application system to the dozer. We are also investigating mounting the planting head on an excavator to limit people going into high-risk areas on steep slopes.
Unemployment
A webinar participant asked how communities in forestry areas react to modernisation. “Nearly 34% of South Africans are unemployed, and mechanised systems reduce employment opportunities. Is there an increased risk of push-back by communities against technology and possible physical damage to growing stocks through arson and theft?
“How does one responsibly employ technology to meet the company/contractor’s needs while minimising the potential impact on the surrounding communities?”
Shweni responded that adopting new technologies will inevitably lead to reduced employment opportunities as work gets done faster and more efficiently. “There will always be unemployment pressure. Our intention to modernise is to improve ergonomics and safety for employees. It is not about replacing jobs. There are opportunities for people to reskill and enjoy better work conditions and decent jobs.”
DRONES
Sam Twala of Ntsu Aviation Solutions presented an overview of the evolution of the remotely piloted aircraft systems (RPAS) or uncrewed air vehicles (UAVs), commonly known as the drone industry, since 2015 and the challenges posed by cumbersome South African regulations.
The forestry industry uses the technology for fire detection work, mapping, crop-spraying and increasingly for forest health management. Investing in a drone equipped with remote sensing and machine learning with enterprise integration is costly, and the technology is changing rapidly. Twala advised forestry companies and contractors to also consider the cost of pilot licences and the impact of the SA Civil Aviation Regulations
He discussed two examples where the regulations are clumsy. The latest drone technology lets one controller fly multiple drones. However, the regulations say one controller can only fly one drone. “It means that if you want to use five drones, you need five pilots, which is expensive,” he explained.
Other sticking points are crop-spraying, Lidar and below-canopy work. “Operating under-canopy is low risk for people and property. However, civil aviation regulations are overkill and not practical or operation-centric.”
SATELLITE IMAGERY
Michael Breetzke of Swift Geospatial’s presentation focused on using satellite imagery to monitor forest operations.
“We are not foresters; we are geographical information systems experts specialising in extracting useable data from satellite imagery. We are based in Pretoria and work in Africa, Australia and Indonesia,” Breetzke explained.
“Partners, relationships and technology are critical. The final product is a modern tool facilitating decision-making on a large scale; it does not replace people. ”
He said there are three ways of accessing satellite data:
- Sentinel 2 data provides free image updates every five days.
- Planet provides daily 3m images
- Maxar offers high-resolution data down to 30cm and can, for example, present 3D data for determining the height of trees.
Swift Geospatial’s services include visual dashboards of data on:
- Site Species Matching Tool
- Carbon sequestration
- Infield stress
- Weather forecasting
- Climate scenarios suitability
- Woodlot mapping and query
- Woodlot monitoring
- Tree survival rate
- Post-fire analysis
- Road network analysis
- New imagery requests
- Deforestation monitoring
BRACKE FOREST
Dr Rafel Ribeiro Soler of Bracke Forest in Brazil explained the century-old company’s history and plantation forestry solutions.
Bracke Forest is a Swedish technology manufacturer recently bought from the Cranab group by Komatsu Forest. Soler said the excavator-mounted P12.b planter is ideal for southern hemisphere applications.
The standard carousel holds 196 seedlings (45mm), and the ripper rips to depths between 400 and 800mm. Accessories include tilt levelling, a slow-release fertiliser applicator and water and gel irrigation. At this stage, it cannot handle seedlings in paper pots.
DRONES IN BRAZIL
The penultimate speaker was Dr Guilherme Oguri . He is a forest engineer and executive coordinator of the Cooperative Programme for Mechanisation and Automation Forestry at Brazil’s Forestry Science & Research Institute (IPEF).
The programme’s objectives are to increase the quality and productivity of silviculture through mechanisation and automation. Drones are mainly used for pesticide applications and mapping using cameras and Lidar.
He described the following experiments:
Weeding using an XAG P30 2020 Serie 2 drone: Spraying glyphosate, saflufenacil or mineral oil herbicides for weed and eucalypt coppice control
- Application dosage = 10 litres per hectare
- Spraying velocity = 5,3m per second
- Application width = 4 metres
- Total area = 137ha
The result was an operational efficiency of 44% and productivity of 2,5ha per h-1
Insect pest management using the same drone: Spraying imidacloprid and vegetable oil for Costalimaita ferruginea vulgate (yellow beetle) control
- Application dosage = 6 litres per hectare
- Spraying velocity = 8,4m per second
- Application width = 6 metres
- Total area = 43ha
The result was an operational efficiency of 47% and productivity of 8,2ha h-1
Ants control using a DJI Agra MG-1P drone applying granular fipronil for Acromyrmex spp control
- Application dosage = 4,5kg per hectare
- Spraying velocity = 6,9m per second
- Application width = 7 metres
- Total area = 236ha
The result was an operational efficiency of 35% and productivity of 3,5ha h-1
Additional quality control research determined the spraying width profile and spraying drift. Evidence of chemicals was found 4m – 64m away from the spraying target area, with less drift concentration further away. The damage caused was not evaluated.
TECHNOLOGY IN FOREST 4.0
The forestry general manager of Hexagon’s Agriculture Division, Ronaldo Soares, rounded off the webinar. Hexagon employs over 20,000 people in 50 countries, with over 4,000 in R&D. His presentation looked at integrating modern technologies in forestry.
Soares advised companies not to rush out and outsource responsibility to a service provider without scoping the project. “Technology is not the ‘silver bullet’. It would be best to decide what you want, when and where. You should appoint someone in the company to be responsible. There is a lot of information available from many actors and several influencing factors,” he said.
“For me, the biggest problem is the lack of standardisation and quality of forestry equipment research and technology manufacturers. The industry, its investors, technology developers and universities should work together to identify problems and find solutions.
“Globally, more has been invested in mechanised harvesting than in silviculture. It is time to talk about investment in silviculture.”
Source: WoodBiz Africa Magazine