• Korean Journal of Agricultural Science
• /
• v.49 no.4
• /
• pp.897-907
• /
• 2022

The purpose of this study is to develop a self-propelled underground crop harvester and its performance was evaluated by measuring the load during actual potato harvesting operations. This study was conducted at a constant working speed of 1 km·h^-1. A load measurement system was installed to measure the actual load and the required working power was analyzed. A hydraulic pressure sensor was also installed to measure the hydraulic pressure. The required hydraulic power was calculated using the hydraulic pressure and flow rate. The results showed that the engine speed, torque, and power during harvesting operation were in the range of 845 - 1,423 rpm, 95 - 228 Nm, and 9 - 31 kW, respectively. Traction power, excluding the hydraulic pump of the tractor and power take-off (PTO) output, was in the range of 9 - 28 kW, and it was confirmed that it occupies a ratio of 16.2 to 50% of the engine rated output. The engine can supply the minimum required traction power to move the vehicle. This means that the engine used in this study could be down-sized to be suitable for an underground crop harvester. In this study, the gear stages of the tractor were not considered. This research thus shows the possibility of developing a self-propelled underground crop harvester.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1990.05a
• /
• pp.84-85
• /
• 1990

• Korean Journal of Medicinal Crop Science
• /
• v.26 no.3
• /
• pp.227-232
• /
• 2018

Background: Angelica gigas Nakai is a perennial herb belonging to the family Umbelliferae. Its roots are utilized in traditional medicine. The aim of this study was to increase the yield of and the content of two indicator components (decursin and decursinol angelate) in A. gigas Nakai. Methods and Results: The roots of A. gigas Nakai were harvested 4-times from late August to late October in 2017. Two agents (trace element-TE, and plant hormone-HM) were applied 4 times at intervals of 2 weeks. The content of the two indicator components were analyzed by high performance liquid chromatography. The HM treatment showed the greatest increase in underground part yield and root diameter. The content of the two indicator components in the control (non-treatment) group was the highest in the underground part, but was higher in the aerial parts in the agent treatment group. After treatment with the agents, the content of the indicator components tended to decrease in the underground part. However, the total content of the indicator components in the two agent treatment groups exceeded the level of 6% set by the Korean Pharmacopoeia. Conclusions: The highest underground part yield was found in the HM treatment group, while the highest content of decursin and decursinol angelate were found in the control group. This study provides basic information for yield improvement in A. gigas.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.6
• /
• pp.848-851
• /
• 2010

The essential factor for house cultivation is water management. Water requirement of crop is the most important for the water management. The water requirement of crop is different according to the area as well as climate condition and growth stage. However, the measurement of PET (Potential Evapo-Transpiration) and crop coefficient (Kc) is very difficult especially in house cultivation. Therefore, the PET and Kc of red pepper are estimated based on the lysimeter experiments carried out by the RDA for 11 years about the ratio of house cultivation to wild cultivation. Periodic PET, mean water requirement (MWR) and accumulated water requirement (AWR) of red pepper cultivated in house are evaluated.

• Korean Journal of Medicinal Crop Science
• /
• v.21 no.3
• /
• pp.179-183
• /
• 2013

This study was carried out to investigate the variation of growth and yield using different planting densities and vinyl mulching in S. miltiorrhiza cultivation. Top plant growth was observed in the $30{\times}30cm$ planting density of S. miltiorrhiza;, plant height, leaves and branches were larger than in the other treatments. Root length, root diameter, and supporting roots of underground part were increased as planting density was wide, and dry root weight was increased in $30{\times}30cm$. However, yield was highest at 294 kg/10a in the planting density of $30{\times}10cm$. The use of 30-31cm white and black vinyl mulching had no significant effect on the plant height of S. miltiorrhiza, as compared to non-mulching. However, the highest volume of leaves and plant weight was observed in plants using 24.7 black vinyl mulching. Dry underground root weight was highest in black vinyl mulching at 21.7 g compared to 17.0 g for non-mulching. Yield per 10a increased by 28% using black vinyl mulching compared to non-mulching. Based on the results of this study, planting density of $30{\times}10cm$ and black vinyl mulching are the most suitable in the cultivation of S. miltiorrhiza.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.11 no.2
• /
• pp.150-155
• /
• 2018

In Korea, the mechanization ratio of field farming is about 58.3%. Especially, mechanization ratio of harvest operation is 10% or less. So, it is required to improve the mechanization ratio of harvest operation to analyze the power requirement analysis of agricultural tractor. The purpose of this study is to analyze power requirement of the underground crop harvester attached on agricultural tractor for traction operation. First, a power measurement system was developed and installed in 45 kW agricultural tractor. Second, field experiments were conducted at two driving speed levels (1.41, 2.17 km/h), and axle torque and rotation speed were analyzed. At 1.41km/h driving speed, the average power requirement of driving axle is 3.13 kW, respectively, at 2.17km/h driving speed, the average power requirement of driving axle is each 4.20 kW. In addition, the field tests show that as the driving speed increases by 53%, the power requirement of the underground crop harvester attached on agricultural tractor increases by 34%. Therefore, it indicated that the power requirement of agricultural tractor was affected by the driving speed.

• Korean Journal of Medicinal Crop Science
• /
• v.8 no.3
• /
• pp.209-215
• /
• 2000

This study was conducted to improve the productivety of Ligusticum chuanxiong HORT. and Cnidium officinale MAKINO by establishing the effects of cultivating conditions. Growth characteristics of underground part of L. chuanxiong under the different mulching treatment showed the highest growth and yield in black vinyl mulching treatment. The highest dry weight of underground parts per plant in mulching treatment was 47.9g at white shading treatment while the lowest one was 16.5g at black shading treatment. Growth characteristics of underground parts C. officinale under the different mulching treatment were the higher in black vinyl mulching rather than in rice straw mulching and white vinyl mulching. Dry weight of underground parts per plant of C. officinale under the different shading treatments was the highest(37.8g) under the white shading while it was lowest(12. 2g) under the black shading.

• Korean Journal of Soil Science and Fertilizer
• /
• v.43 no.6
• /
• pp.812-822
• /
• 2010

Water management is the most important and difficult problems in crop cultivation. The farmers are doing irrigation, those when to irrigate and how much to irrigate, depending on their experiences. The irrigation manual as water saving is possible, those irrigation interval and amount of irrigation, are developed based on the lysimeter experiments carried out by the RDA for 11 years about potential evapotranspiration, crop coefficient. The manual can be used with easy to the farmer without soil sampling and any kinds of sensors measuring soil water status.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2003.10a
• /
• pp.179-180
• /
• 2003

• Korean Journal of Medicinal Crop Science
• /
• v.20 no.3
• /
• pp.177-183
• /
• 2012

To develop the practical cultivation for paddy field, we investigated the properties of paddy soil, growth characteristics and ginsenoside content of 6-year-old ginseng, Cheonpung variety between poor drainage class (PDC) and imperfect drainage class (IDC). Groundwater level in PDC showed monthly small changes of 20~30 cm, while IDC showed monthly great changes of 28~71 cm depending on rainfall. Soil moisture content in PDC and IDC was 17.2%, 22.5%, respectively. Air temperature in IDC was lower than $0.3^{\circ}C$, while soil temperature was higher than $0.8^{\circ}C$ compare to PDC, respectively. Main soil color of PDC was grayish olive, while IDC was brownish olive. PDC showed yellowish mottles only at underground of 20~40 cm, while IDC showed that at underground of 30~90 cm. IDC showed lower pH, EC, potassium, calcium and magnesium content, but higher organic matter, phosphate, and iron content than that of PDC, respectively. All of EC, organic matter, potassium, calcium, and magnesium content were decreased, but iron content was increased at the subsoil layers of PDC. All of EC, organic matter, phosphorus, and potassium content were decreased, but calcium and magnesium content were increased at the subsoil layers of IDC. Root yield in IDC was more increased by 33% than that of PDC. The moisture content and rusty ratio of ginseng root in IDC were lower than that of PDC. Ginsenoside content in IDC was higher than that of PDC because the ratio of lateral and fine root showing relatively high content of ginsenoside was higher in IDC than that of PDC.