• Journal of Forest and Environmental Science
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• v.33 no.2
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• pp.147-153
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• 2017

The purpose of this study was to examine productivity and cost of tree-length harvesting using cable yarding system in a larch (Larix leptolepis) clear-cutting stand located in Pyeongchang-gun, Gangwon-do. We used tree-length harvesting method using cable yarding system with a tower yarder HAM300. The productivity was $17.6m^3/hr$ for felling, $12.4m^3/hr$ for delimbing, $4.2m^3/hr$ for yarding, and $8.1m^3/hr$ for processing. The total cost of the harvesting system was $48,381won/m^3$, which was majorly composed of yarding operation cost, at $40,169won/m^3$ (79.3%), while felling had the lowest cost at $1,154won/m^3$ (4.1%). Major factors affecting felling and processing productivity was tree volume and the number and thickness of branches for delimbing productivity. In addition, we suggest that training and education for machine operators were critical to improve yarding productivity.

• Journal of Forest and Environmental Science
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• v.30 no.1
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• pp.107-112
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• 2014

The productivity and cost of clear cutting operations were examined to broaden our knowledge on the harvesting system in a Larix leptolepis stand of Korea. The harvesting system was divided into tree operations which were chainsaw (STIHL MS440) felling, tower yarder (Koller301-4) yarding and harvester (WOODY H50) processing. The average cycle time of felling, yarding and processing were 98 s/cycle, 245 s/cycle and 150 s/cycle. The total stump-to-pile operational productivity was 43.07 $m^3/hr$. The highest production activity was the felling 17.93 $m^3/hr$, followed by the productivity of processing 15.62 $m^3/hr$ and then by the productivity of yarding 9.52 $m^3/hr$. In addition the total stump-to-pile operational cost was 24,086 $won/m^3$. The highest cost activity was the yarding 14,557 $won/m^3$ (60.4% of the total cost), followed by the costs of processing 8,461 $won/m^3$ (35.2%) and then by the costs of felling 1,068 $won/m^3$.

• Journal of Forest and Environmental Science
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• v.32 no.2
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• pp.189-195
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• 2016

Logging equipment and method have a major influence on harvesting productivity and cost. This study investigated the productivity and operational costs of tree-length cable yarding system using HAM300, a domestically developed tower yarder. We tested HAM300 for thinning operation in Pinus densiflora stands at Gangreung, Gangwon-do on April, 2014. To assess the productivity we conducted time study for each stage of the operation. When the average time/cycle was examined for each stage of the operation, the longest was for yarding (241 sec), followed by delimbing (237 sec), felling (153 sec), and processing (103 sec). Furthermore, productivity for felling was $8.6m^3/hr$, followed by delimbing ($5.1m^3/hr$), yarding ($3.5m^3/hr$), and processing ($8.1m^3/hr$). The total cost for the tree-length logging system was $58,446won/m^3$, of which the majority was incurred by the yarding cost at $46,217won/m^3$ (79.3%), whereas the lowest cost was for felling at $2,359won/m^3$ (4.1%). We suggest that it is necessary to foster specialized operators and provide training in operating the tower yarder thereby implementing efficient harvesting system resulting from low-cost yarding.

• Journal of Biosystems Engineering
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• v.39 no.2
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• pp.134-141
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• 2014

Purposes: This study was to validate the Robotic Smart Work System that can provides better working conditions and high productivity in unstructured environments like bio-industry, based on a tele-operation system for fruit harvesting with low cost 3-D positioning system on the laboratory level. Methods: For the Robotic Smart Work System for fruit harvesting and cultivation management in agriculture, a vision based tele-operating system and 3-D position information are key elements. This study proposed Robotic Smart Farming, an agricultural version of Robotic Smart Work System, and validated a 3-D position information system with a low cost omni camera and a laser marker system in the lab environment in order to get a vision based tele-operating system and 3-D position information. Results: The tasks like harvesting of the fixed target and cultivation management were accomplished even if there was a short time delay (30 ms ~ 100 ms). Although automatic conveyor works requiring accurate timing and positioning yield high productivity, the tele-operation with user's intuition will be more efficient in unstructured environments which require target selection and judgment. Conclusions: This system increased work efficiency and stability by considering ancillary intelligence as well as user's experience and knowhow. In addition, senior and female workers will operate the system easily because it can reduce labor and minimized user fatigue.

• Journal of Biosystems Engineering
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• v.41 no.4
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• pp.294-303
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• 2016

Purpose: This study aimed to evaluate the profitability of four selective mechanization systems in rice cultivation. Methods: Field experiments were conducted in the farmers' field during the wet season (June to November) of 2015 in Bangladesh. Mechanization systems were applied to evaluate four different selective levels (treatment) in eleven consequent operations. Seedlings were raised in a traditional seedbed and trays for manual and mechanical transplanting, respectively. Land preparation, irrigation, fertilizer, pesticide, carrying, and threshing and cleaning operations were performed using the same method in all the experimental plots. The mechanical options in the transplanting, weeding, and harvesting operations were changed. The mechanization systems were $S_1$ = hand transplanting + hand weeding + harvesting by sickle, $S_2$ = mechanical transplanting + Bangladesh Rice Research Institute (BRRI) weeder + reaper, $S_3$ = mechanical transplanting + BRRI power weeder + reaper, and $S_4$ = mechanical transplanting + herbicide + reaper. This experiment was performed in a randomized complete block design with four replications. Power tiller, rice transplanter, BRRI weeder, BRRI power weeder, self-propelled reaper, BRRI open drum thresher, and BRRI winnower were used in the respective operations. Accordingly, the techno-economic performances of the different technologies were calculated and compared with those of the traditional system. Results: The mechanically transplanted plot produced 6-10% more yield than the hand transplanted plot because of the use of tender-aged seedlings. Mechanical transplanting reduced 61% labor and 18% cost compared to manual transplanting. The BRRI weeder, BRRI power weeder, and herbicide application reduced 74, 91, and 98% labor, respectively. The latter also saved 72, 63, and 82% cost, respectively, compared to hand weeding. Herbicide application reduced the substantial amount of labor and cost in the weeding operation. Mechanical harvesting also saved 96% labor and 72% cost compared to the traditional method of harvesting using sickle. Selective mechanization saved 15-17% input cost compared to the traditional method of rice cultivation. Conclusions: Mechanical transplanting with the safe use of herbicide and harvesting by reaper is the most cost- and labor-saving operation. The method might be the recommended set of selective mechanization for enhancing productivity.

• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.221-229
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• 2015

The purpose of study was to broaden our knowledge on the productivity and cost of thinning operations which has become increasingly practiced in Korea. The thinning operations were conducted in a 40-year old larch (Larix leptolepis) stand, including chainsaw felling and processing at the stump, followed by yarding tree-length logs using a Koller K301-4 tower yarder. The logs were further processed and sorted into 1.8 m and 3.6 m log piles at the landing. We used a standard time study method to evaluate key variables that affect the productivity of thinning operations. The total stump-to-pile operational cost was $41,707won/m^3$. The highest cost activity was the yarding phase which cost $20,083won/m^3$ (48.2% of the total cost), followed by the costs of processing treelength materials into marketable log lengths ($12,143won/m^3$; 29.1%), and then by the costs of sorting/piling the processed logs ($5,039won/m^3$; 12.1%). It was interesting to see that felling and processing trees at the stump had low costs at $1,315won/m^3$ (3.2%) and $3,127won/m^3$ (7.5%), respectively. We used the detailed time study data to develop regression equations which were to predict yarding productivity. Our analysis showed that harvesting system cost was highly sensitive to the number of logs, yarding distance and lateral distance per turn, respectively.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.217-232
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• 2021

This study calculated the productivity and cost of extraction and processing of logging residues by cut-to-length (CTL) and whole-tree (WT) harvesting methods. In addition, the comparative analysis of the characteristics of wood chip fuel to examine whether it was suitable for the fuel conditions of the energy facility. In the harvesting and processing system to produce the wood chips of logging residues the system productivity and cost of the CTL harvesting system were 1.6 Gwt/SMH and 89,865 won/Gwt, respectively. The productivity and cost of the WT harvesting system were 2.9 Gwt/SMH and 72,974 won/Gwt, respectively. The WT harvesting productivity increased 1.3times while harvesting cost decreased by 18.7% compared to the CTL harvesting system. The logging residues of wood chips were not suitable for CTL wood chips based on International Organization for Standardization (ISO 17225-4:2021) and South Korea standard (NIFoS, 2020), but the quality (A2, Second class) was improved through screening operation. The WT-unscreened wood chips conformed to NIFoS standard (second class) and did not conform to ISO but were improved through screening operation (Second class). In addition to the energy facility in plant A, all wood chips except CTL-unscreened wood chips were available through drying processing. The WT-unscreened wood chips were the lowest at 99,408 won/Gwt. Plants B, C, and D had higher moisture content than plant A, so WT-unscreened wood chips without drying processing were the lowest at 57,204 won/Gwt. Therefore, the production of logging residues should improve with operation methods that improve the quality of wood chips required for applying the variable biomass and energy facility.

• Journal of Korean Society of Forest Science
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• v.105 no.4
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• pp.441-448
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• 2016

The purpose of this study was to broaden our knowledge on the productivity and costs of felling operation in three different harvesting methods(whole tree, tree-length and cut-to-length). Felling was conducted in three different harvesting methods with two workers who have different work experiences. Worker A and B have had felling experiences for about 5 years and 15 years, respectively. Felling productivity in whole tree method was $10.3m^3/SMH$ for worker A and $12.7m^3/SMH$ for worker B. Felling costs for worker A and B were $2,066won/m^3$ and $2,201won/m^3$, respectively. Although felling productivity of worker B in whole tree method was higher than worker A, felling costs of worker A were similar to worker B because the wage of worker B was more expensive than the wage of worker A (p>0.05). In tree-length method, felling cost of worker B were cheaper than that of worker A. Felling productivity and cost in tree-length method were $2.2m^3/SMH$ and $9,890won/m^3$ for worker A and $3.3m^3/SMH$ and $8,459won/m^3$ for worker B, respectively (p<0.05). In cut-to-length method, felling productivity and cost were $2.3m^3/SMH$ and $9,584won/m^3$ for worker A and $3.0m^3/SMH$ and $9,395won/m^3$ for worker B, respectively. Felling productivity of worker B was higher than that of worker A(p>0.05). Our preliminary results found that harvesting methods and worker's experiences highly affect on the productivity and costs of felling operations. These results should be useful for forest managers when planning cost-effective harvesting operations.

• Journal of Biosystems Engineering
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• v.7 no.2
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• pp.36-44
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• 1983

Farm population was rapidly decreasing due to shift of the people from farm sector to the non-farm sector caused by the economic growth of the country. Especially, a great shortage of farm labor in busy farming period in June and October is becoming a serious problem in maintaining or promoting land productivity. The peak of labor requirement in summer is caused by rice transplanting and barley harvesting. In order to reduce the restrictions imposed on farm management by the concurrence of labor requirement and the lack of labor, the experimental study for mechanization of barley harvesting has been carried out in the fields. 1. The machines for barley harvesting were knap-sack type reapers, windrow reaper (power tiller attachment), binder and combine. The order of higher efficiency of machine for barley harvesting was combine, binder, windrow reaper (WR), knapsack type reaper 1(KSTR1), and knap sack type reaper 2(KSTR2; mist and duster attachment). 2. The ratio of grain loss for the manual, binder, and combine plot was about four percent of total field yield. 3. The total yield of barley in 35 days and 40 days harvesting after heading were 514 kg and 507kg per 10 ares respectively. The yield of 35 days-plot was higher than other experimental plots. 4. The lowest yield was recorded in 30 days-plot due to the large quantity of immatured grains and having lighter 1000-grain weight. The ratio of immatured grains was 2.66 percent and 1000-grain weight was 29.4 grams. 5. The total harvesting cost of the windrow reaper was 10,178 won per 10 ares. It was the lowest value compared to other machines. The next were combine, binder, KSTR1, KSTR2, and manual in sequence. As a result, the optimum time of barley harvesting for mechanization was 35-40 days after heading. Combine, binder, and windrow reaper were recommended as the suitable machines for barley harvesting in the work efficiency. However, in total harvesting cost, the windrow reaper was the most promising machine for barley harvesting.

• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.583-593
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• 2022

The harvesting system in South Korea faces the problems of aging workers and high wages, so it is necessary to improve the operation system and train workers to use high-performance forestry machines. This study compared the effectiveness and costs of yarding and processing operations between a multi-operation system using a tower yarder (HAM300) and a processor (KESLA 20SH) with those of a single-system using a forestry combi-machine. A whole-tree (cable) yarding operation was conducted in the clear-cutting area located at Compartment 15, Gwangneung Experimental Forest, National Institute of Forest Science, and the productivity and cost of multi- and single-system were analyzed. The productivity of the single-system was 1.5 m³/PMH and 1.6 m³/PMH higher than that of the multi- system because the single-system produced 1 log/cycle more than the multi-system in the yarding operation. The cost was approximately 12.1% lower for the single-system (￦36,113/m³) than for the multi-system (￦41,065/m³). The costs of the single-system and multi-system were decreased by maximums of 22.6% and 15.9%, respectively, by decreasing the idle time.