• Journal of Biosystems Engineering
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• v.40 no.1
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• pp.35-46
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• 2015

Purpose: To present a flexible and accurate autonomous solution for creating any desired row spacing value between the hydroponic gullies in multilayer growing units, and evaluate the capabilities and performance of the relevant automated system through the use of virtual prototyping technique. Methods: To build the virtual prototype of the system, CAD models of its different parts, including an autonomous vehicle and the mechanical mechanisms embedded in the multilayer growing unit, were developed and imported into the RecurDyn simulation software. In order to implement the automated row spacing operation, three spacing modes with different loading cycles and working steps were defined, and the operation of the system was simulated to obtain the target row spacing values specified for each of these modes. Results: Motion profiles related to the horizontal displacement of: 1) the lower and upper sliding bars installed in the cultivation layers, and 2) the hydroponic gullies, during the simulation of the system operation, were generated and analyzed. No deviation from the specified target spacing values was observed at the end of simulations for all spacing modes. Conclusions: The results of the motion analysis obtained by simulating the system operation confirm the effectiveness of the control scheme proposed for automated row spacing of gullies. It was also found that proper sequencing of the loading cycles and the precision of the working strokes of the upper bars are the critical factors for establishing a certain row spacing value. Based on the simulation results, precise control of the back and forth motions of the upper bars is highly necessary for sound operation of the real system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.4
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• pp.364-367
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• 1999

Swordbean was recently introduced to Korea, and cultural technique for stable production, e.g. optimum seeding date and planting space, has not been established. This experiment was conducted to elucidate the changes of growth characteristics, yield components, and yield as affected by different seeding dates and planting spaces. Days to flowering was shortened by 4∼28 days as seeding was delayed. Stem diameter, number of pods per plant, number of seeds per plant, 100-seed weight, and seed yield tended to increase with delaying seeding up to 5 April and then to decrease with further delaying seeding. These results indicate that optimum seeding date of swordbean in unheated polyvinyl house would be early April. Although, the swordbean exhibited large increases in plant height, number of branches per plant, and stem diameter at the wider spacings, planting space could be decreased to the 60 cm plant-spacing and 30 cm row-spacing with no deleterious effect on yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.153-160
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• 1969

Experiments on sweet sorghum(sorgo) with different population per unit area were conducted from 1966 to 1968 for the first time in Korea. By increasing plant population stalk weight, refinable sugar and seed weight per plot were increased, but stalk weight per plant, brix percentage, sugar content, stem diameter and 1, 000 seed weight were decreased. Plant height, maturity and lodging were not affected by the treatments. The result obtained has suggested that the effects of plant spacing within row on the characteristics of plant growth and on yields were greater than those of row width. Negative correlations existed between sugar content and sugar yield, and seed weight per plant and seed yield. The optimal plant population in this study ranged from 16, 700 to 22, 200 plants per 10a, row width of 60cm and plant spacing in row of 15 to 20cm resulted in the highest sugar and seed.

• Journal of Bio-Environment Control
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• v.22 no.3
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• pp.256-261
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• 2013

The spacing between plug cells and cell volume of each plug cell for nursing tomato seedlings were studied to know the effects on seedling growth and early yield. There were four treatments. The spacing of plug cells was done (OK) or not (NO) in case of cell spacing. The cell number in a plug tray was set to 40 or 50 in case of cell volume. The growth environment and irrigation regime were the same in all of the treatments during the experiment period. The photosynthetic rates, seedling qualities, yield and yield speed were significantly affected by both of the treatments. The photosynthetic rates and seedling qualities were the best in 40S-OK following by 50S-OK, 40S-NO, and 50S-NO while the yield was the best in 40S-OK following by 40S-NO, 50S-OK, 50S-NO. It means the spacing gives more impact than the cell volume in the stage of nursing but the cell volume gives more impact than the spacing after the stage of nursing. In the conclusion the spacing of plug cells in appropriate nursing stage is needed with the appropriate cell volume to make high quality of seedlings and high yield.

• Proceedings of the Korean Society of Crop Science Conference
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• 1989.05a
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• pp.32-33
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• 1989

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.212-217
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• 1981

The evaluate the effect of plant spacing on cured leaf of burley tobacco, the row spacings divided to 90, 105, 120cm and hill spacings to 30, 35, 40cm within each row. Growth amount per plant increased with thinner row and wider hill spacing in the same planting density. Relative light intensity increased with thinner row spacing in cutters and leaf and showed the positive correlation with quality. When the planting density was equal, the wider hill spacings, the more effective in utillization of solar radiation. The more plants per l0a were, the greater yield was obtained, and in the case of 3,200 plants per 10a (the most dense planting plot) was 267kg. But, quality, total-alkaloid and total-nitrogen content decreased with dense planting. Value per 10a was highest in the plots of 90 $\times$ 40cm and $105{\times}40cm$. In conclusion the optimum density level was 2,400 to 2,700 plants per 10a and spacing of tobacco either in 105 $\times$ 35 cm or 105 $\times$ 40cm seems to be most appropriate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.231-237
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• 1986

Under the different conditions of planting density and nitrogen level with aromatic tobacco, some agronomic characters of tobacco like plant height, leaf size, LAI, yield and price were investigated in view of aroma volatile acid contents, the main compounds contributing to the aroma of oriental leaf tobacco. The closer a spacing interval became, the smaller the growth of plant and the leaf size with increment of yields, until about 22,000 plants per 10 are. But the leaf size became smaller without increment of yield when the planting density became more than 22,000 plants per 10 are. There were definite trends toward increase in leaf size, LAI and yield with increase in nitrogen rate. Correlation coefficient between aroma volatile and plant height, largest leaf length, one leaf area was -0.49, -0.49 and -0.47, respectively, showing significance at 1 % level. But LAI (r=-0.14) and dry weight of unit leaf area(r=0.25) was not observed to be significantly associated with aroma volatile, respectively. The results suggest that closer spacing is desirable for smaller leaves, higher contents of aroma volatile and for increased yield.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.127-138
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• 2018

In this study, the operational characteristics of a domestic vegetable transplanter were investigated. The main functional components and power path of the tranplanter were analyzed. The link structure of transplanting device waskinematically analyzed, and 3D modeling and dynamic simulation were performed. Based on this analysis, the trajectory of the bottom end of the transplanting hopper was analyzed. Also, the plant spacing according to the engine speed and the shifting stage of transplanting transmission was analyzed and verified by field test. As main results of this study, the transplanting device is one degree of freedom(DOF) 4-bar link type mechanism which comprises 10 links and 13 rotating joints. The transplanting hopper plants seedlings in a vertical direction while maintaining a constant posture by the links of transplanting device. The power is transmitted to both the driving part and transplanting part from the engine, and the maximum and minimum plant spacing of the transplanting device were 428.97 mm and 261.20 mm.

• Journal of Bio-Environment Control
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• v.14 no.1
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• pp.7-14
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• 2005

This study was conducted to develop a chain conveyor-type, row-spacing system for a plant factory. The developed system was evaluated for its practical use in growing plants. Results are intended to provide technical suggestions on the row spacing for hydroponically grown vegetables in a plant factory. The designed row-spacing system for a plant factory could be adjusted by four stages with a conveying speed range of $5.3\~15.8cm{\cdot}s^{-1}$ and with a row-space range of 10-25cm. The torque of driving shaft was measured with a torque range of 11.7-33.3 N$\cdot$m according as a trough weight changes with a range of $17\~935$ N. A measured value was $5.9\~9.8\;N{\cdot}m$ lower than a theoretical value. Travel reduction rate was shown up $1.6\~1.9\%$. The conveying time of trough was shown up 2.24 seconds in case that the designed value was 2.26 seconds. The system was evaluated to be functioning effectively according to the initial design factors in the test.

• Journal of agriculture & life science
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• v.53 no.4
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• pp.113-124
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• 2019

In this study, the operational characteristics of a cam-type vegetable transplanter which usually used in domestic was analyzed and operating mechanism of a transplanting device was analyzed. The main components and power path of the transplanter were analyzed. The maximum and minimum control cycles according to the moving speed and the plant spacing were analyzed. 3D modeling and simulation were performed to derive the trajectory of the bottom end of the transplanting hopper and the plant spacing at the each operating condition. The simulation results were verified by the field tests. As main findings of this study, the transplanting device has one degree of freedom (DOF) which consist of 13 links, 17 rotating joints and 1 half joint, and each part has composite structure with cam and links. By continuous and repetitive motion of the structures of transplanting device, the transplanting hopper plants the seedling in the ground with a vertical direction, and the seedling was planted stably. The power is transmitted to the driving part and transplanting device from the engine, and the maximum and minimum plant spacing of the transplanting device were about 900 mm and 350 mm, respectively.