• Korean Journal of Soil Science and Fertilizer
• /
• v.46 no.2
• /
• pp.81-86
• /
• 2013

For organic farming, green manure crops such as leguminous forages and barley have been broadly used to improve soil fertility and soil physical and chemical properties by repeatedly cutting and mulching them directly as winter crop in the field in the rotation. In this investigation we selected 78 agricultural farm corporations as well as individual organic farmhouses related to crop rotation from greenmanure crops to main crops in order to analyze the relationship of cropping system between main crops and green manure crops. The results showed that the green manure crops were divided into two groups as leguminous and nonleguminous crops, representing that those are limited to specific climate and farming systems of regions. Also the 10 or less green manure crops including sudangrass, hairyvetch, italian ryegrass, sorghun, buckwheat, oat, pea, rye, clover, and canola which belong to leguminous crops which are presently cultivated from the organic farmhouses within the rotational crop system. We also confirmed that the major main crops are sweet potato, soybean, corn, tobacco, spinach from usage frequency analyzed by NetMiner H 2.6 which was used to estimate the rotational cropping system among the green manure crops and main crops.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.3
• /
• pp.259-267
• /
• 2010

This study was performed at Rice and Winter Cereal Crops Department of NICS during 2007 and 2008 to investigate the characteristics of rice leaf emergence and to obtain basic data which can be used for rice growth simulation model by which we can forecast rice growth stage and heading date accurately under different cultivars, transplanting date, and climatic conditions. To confirm leaf emergence rate according to rice maturing ecotype, we surveyed the leaf emergence rate and heading date of Unkwangbyeo, Hwayoungbyeo and Nampyeongbyeo which are early maturing, medium maturing and medium-late maturing cultivars, respectively, according to seedling raising duration and transplanting time. When seedling duration was 15 days, the growth duration between transplanting time and completion of flag leaf emergence on main culm were 51.5~78.3 days in Unkwangbyeo, 55.3~87.9 days in Hwayoungbyeo and 58.4~98.4 days in Nampyeongbyeo, respectively. When seedling duration was 30 days, they were 50.1~75.5 days in Unkwangbyeo, 52.4~84.7 days in Hwayoungbyeo and 56.4~93.8 days in Nampyeongbyeo, respectively. As transplanting time delayed, the emerged leaf number after transplanting decreased in all rice cultivars. The cumulative temperature between transplanting time to completion of flag leaf elongation on main culm were $1,281^{\circ}C{\sim}1,650^{\circ}C$ in Unkwangbyeo, $1,344^{\circ}C{\sim}1,891^{\circ}C$ in Hwayoungbyeo and $1,454^{\circ}C{\sim}2,173^{\circ}C$ in Nampyeongbyeo, respectively. Leaf emergence rate on main culm were precisely represented by equation, y = $y_0$ + a / [1 + exp( - (x - $x_0$) / b)]^c, when we used daily mean temperature as variable.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.524-535
• /
• 2020

This study was conducted to derive implications for the dissemination and expansion of subtropical crops in farms. To this end, the cultivation trends and main producing areas of promising subtropical crops in Korea were analyzed. Analysis results found that the cultivation area of crops, excluding mango, was stagnating or decreasing. The main producing areas of domestic subtropical crops are located on Jeju Island (mango, dragon fruit), in Gyeongsangnam-do (papaya), and in Jeollanam-do (turmeric). Guava and Yeoju could not define the main producing area. For all crops, the percentage of cultivated area in the top 10 regions was high, but only half of the regions maintained the ranking. These results imply that the introduction and abandonment of subtropical crops are frequent. The dissemination and expansion of subtropical crops are justifiable in terms of responding to climate change in the future and creating new income for farms. Therefore, government support policies and agricultural promotion agencies need to be established.

• Korean Journal of Organic Agriculture
• /
• v.9 no.4
• /
• pp.95-111
• /
• 2001

To carry out the Integrated Fruit Production(IFP), researches on cover crops as well the Integrated Pest Management(IPM) and the Integrated Nutrition Management(INM) should be very important. These concepts are neither clear nor connective till now. The researches on cover crops in Europe and USA are being kept within the category of IFP. Main researches on fruit trees for sustainable agriculture in Italy are new variety creation, development of growing techniques, pest and disease control, and cover crops management, etc. It is necessary of fruit industry in Korea to maintain good quality and taco-friendly fruit production. For this goal, we need international cooperation with highly developed countries in Europe. In first step, we should enlarge research areas and analyze results obtained to get farmers understood the concept of cover crop growing, Furthermore, we make researches more profoundly on cover crops growing considering tree age, mixing rates among cover crops, seeding and cutting time for cover crops, and so on. Researchers, specialists of agricultural extensions, and farmers should concentrate their opinions and conduct IFP together. The IFP should go on systematically and reach finally to get certificates internationally by the International Organization for Biological and integrated Control of Noxious Animals and Plants(IOBC) to enhance selling and exporting fruits.

• Journal of Climate Change Research
• /
• v.7 no.2
• /
• pp.193-203
• /
• 2016

The importance of forecasting agricultural production is receiving attention while climate change is accelerating. This study suggested three types of crop yield forecasting model for major vegetable crops by using downscaled meteorological information of main production area on farmland level, which identified as limitation from previous studies. First, this study conducted correlation analysis with seven types of farm level downscaled meteorological informations and reported crop yield of main production area. After, we selected three types of meteorological factors which showed the highest relation with each crop species and regions. Parameters were deducted from meterological factor with high correlation but crop species number was neglected. After, crop yield of each crops was estimated by using the three suggested types of models. Chinese cabbage showed high accuracy in overall, while the accuracy of daikon and onion was quiet revised by neglecting the outlier. Chili and garlic showed differences by region, but Kyungbuk chili and Chungnam, Kyungsang garlic appeared significant accuracy. We also selected key meteorological factor of each crops which has the highest relation with crop yield. If the factor had significant relation with the quantity, it explains better about the variations of key meteorological factor. This study will contribute to establishing the methodology of future studies by estimating the crop yield of different species by using farmland meterological information and relatively simplify multiple linear regression models.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.27 no.4
• /
• pp.314-339
• /
• 1982

Fluctuating climate is still most important environmental constrain, although improved modem agricultural technology has succeeded to increase crop production in the world. To stabilize the food production under fluctuating weather conditions, it is very needed to obain the quantitative information of interactions between crops and climate. The main purpose of this paper is three hold. Using the JIBP-data, the dry matter accumulation of rice crops is studied in relation to weather indexes (\SigmaTa and \SigmaSt). Temperature dependence of the yield index of rice is analyzed as to air temperature and water temperature. \SigmaT$_{10}$ -fluctuations are studied using meteorological data at various stations. The possible shift of \SigmaT$_{10}$ -isopleths due to climate fluctuation is evaluated. The second interest is in the plant climate of rice crops. Using results of canopy photosynthesis, it is pointed that the canopy structure has most important implication in plant climate. Leaf-air, stomatal, and mesophyll resistances of rice crops are described in relation to weather conditions. The change in light condition and aerodynamical property of rice crops with the growth is illustrated. The energy partition is also studied at different growing stages. Third point is to show in more detail effective countermeasures against cold irrigation water and cool summer. Heat balance of warming pond and polyethylene tube as a heat exchanger is studied to make nomo-grams for evaluating the necessary area and necessary length. Effects of windbreak net on rice crops are illustrated by using experimental and simulation results.lts.

• Solar Energy
• /
• v.10 no.3
• /
• pp.27-34
• /
• 1990

The main objective of this study was to find the relationship between transpiration rate and environmental factors for crops in hydroponic culture within plastic greenhouse by using the computer model developed from the heat balance around leaves of a crop. A computer model was developed and verified through comparison with the experimental results for lettuce in hydroponic culture in a polyethylene film house. The model may be extensively used for the water management and thermal environment study of crops in protected culture, if the supplemented studies for some crops would be accomplished.

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.6
• /
• pp.518-524
• /
• 2014

Heavy metal pollution in agricultural field near at the abandoned metal mines has been a critical issue in Korea. In particular, bioaccumulation in plants can have detrimental effect on human health. Main objective of this research was to examine arsenic (As) concentration in soil with varied extraction methods and to determine bioaccumulation and biological transfer factor in different crops. Results showed that bioaccumulation ratio of As for total contents in soil was ordered leafy and stem vegetables (1.19%) > fruit bearing vegetables (0.79%) > pulses (0.40%) > root vegetables (0.36%) with different crop species. Among 6 different extraction methods, all of extraction methods showed high correlation ($R^2=0.87-0.97$) except DTPA ($R^2=0.25$) when comparing As concentration in soil extracted with different extractants and As concentration in each crops. Calculated biological transfer factor was ranged 0.002-0.018 depending on crop species. Overall, concentration of As in crops can be varied and best management practice for minimizing bioaccumulation of As should be considered depending on crop species.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.5 no.1
• /
• pp.21-27
• /
• 2024

Harmful pet insects, if not controlled, can negatively affect people, plants and their surrounding environment. In Vietnam, all crops are regularly impacted by pest insects. In serious cases, crops can be totally destroyed by insect pests. Harmful insects that damage crops often grow fast and increase rapidly. Therefore, research on insects is crucial for managing pests, protecting crops, and forecasting pest situation in the following years. This study aimed to collect data regarding changes of pests on rice and corn as two main crops in four provinces in Red River Delta of Vietnam, including Thai Binh, Nam Dinh, Ha Nam, and Hung Yen, from 2018 to 2022. Primary data were collected from reports of government agencies and official statistics. Based on these data, this study evaluated changes of pest insects in five years, discussed reasons for such changes and response methods, and forecasted pest's behavior in the following years. Significant findings of this study include the fact that Vietnam has to face many difficulties to develop its agricultural sector. For insect management, an essential action is to do ground surveys to gather all related data including weather data, pesticide data, crop yield, and product quality. This information is meaningful for finding out causes of changes, understanding relationships between insects and surrounding factors, and predicting the situation in the following years.

• Journal of Bio-Environment Control
• /
• v.15 no.4
• /
• pp.396-399
• /
• 2006

This study was conducted to investigate the desalinizing effect of some vegetable crops (beet, crown daisy, kale, lettuce, spinach, sweet com, and tomato) in salinized soil. The soil was treated with highly concentrated nutrient solutions and the growth of these crops was compared and soil salinity was monitored. The plant height of lettuce and crown daisy inhibited severely in with EC $5dS{\cdot}m^{-1}$ salinized soil. Soil EC level was the lowest in soil where tomato was cultivated followed by corn and kale. The residual level of $NO_3$ was higher in soils used for cultivation of corn, tomato, and kale, that of K was higher in soils used for cultivation of corn, tomato, and beet, and That of $P_2O_5$ was higher in soils used for cultivation of corn and tomato. Although the desalinizing effect was greatest by tomato and corn after 60 days of cultivation. Quality of the these crops was low and the cultivation periods of these crops overlapped with that of the main crops. Kale, on the other hand showed less growth inhibition in salinized soil, greatest desalinating effect based on fresh weight. In addition this crop only needs 30 days of cultivation period. Therefore, kale was most efficient crop in desalinizing considering crop quality, a short cultivation period, and nonoverlapping cultivation time with the main crops.