• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.367-376
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• 2021

Strawberry cultivation in Korea is grown in greenhouse, but most farms manage their water supply using a timer control method based on the experience of growers. The timer control has problems in that it is difficult to consider the weather condition, the growth stage of crops, and the moisture content of the substrate, so that the crops cannot be managed at an optimal level, and the accuracy of cultivation management are lacking. The watering methods using integrated solar irradiance and substrate moisture contents are control systems that provide eco-friendly and precise water supply considering the growth conditions of crops. The purpose of this study was to compare the combined water supply control with integrated solar irradiance and substrate moisture contents and timer control method in hydroponic cultivation of strawberries using coir, and to set the optimal integrated solar irradiance level for complex water supply control. The irrigation system was automatically watered when it reached 100, 150, 250 J·cm^-2 based on the external solar irradiance, and forced irrigation was performed at a substrate moisture content of less than 60% in all treatments. The amount of irrigation at once was 50 mL. The timer treatment was applied as a control. The smaller the level of integrated radiation to start watering, the greater the daily amount of irrigation. Both the fresh weight and dry weight per plant were higher in the complex irrigation control method than the timer control, and the 100 and 150 J·cm^-2 treatment had the highest fresh weight, and the 100 J·cm^-2 treatment showed a significantly higher dry weight. The yield was also significantly higher in the complex control method than in the timer, and the early yield increased as the level of integrated solar irradiance was smaller. The fresh weight of fruit was the lowest in the timer-controlled irrigation. As a result of this study, the possibility of combined control irrigation method using integrated solar irradiance and substrate moisture content was confirmed for precise water supply management of strawberries in hydroponics.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.129-160
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• 2019

Background: Characterizing and describing soils and land use and make a suggestion for sustainable utilization of land resources in the Ethiopian Rift valley flat plain areas of Lake Chamo Sub-Basin (CSB) are essential. Objectives: To (1) characterize soils of experimental area according to World Reference Base Legend and assess the nature and extent of salinity problems; (2) characterize land use systems and their role in soil properties; and (3) identify best land use practices used for both environmental management and improve agricultural productivity. Methods: Twelve randomly collected soil samples were prepared from the above land uses into 120 composites and analyzed. Results: Organic carbon (OC) and total nitrogen (TN) were varied along different land uses and depleted from the surface soils. The soil units include Chernozems (41.67%), Kastanozems (25%), Solonchaks (16.67%), and Cambisols (16.67%). The identified land uses are annual crops (AA), perennial crops (PA), and natural forest (NF). Generally, organic carbon, total nitrogen, percentage base saturation (PBS), exchangeable (potassium, calcium, and magnesium), available phosphorus (P₂O₅), manganese, copper, and iron contents were decreased in cultivated soils. Soil salinity problem was observed in annuals. Annuals have less nutrient content compared to perennials in irrigated agriculture while it is greater in annuals under rainfed. Clay, total nitrogen, available phosphorus, and available potassium (K₂O) contents were correlated positively and highly significantly with organic carbon and electrical conductivity. Conclusion: Management practices that improve soil quality should be integrated with leguminous crops when the land is used for annual crops production.

• Mycobiology
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• v.49 no.5
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• pp.461-468
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• 2021

The genus Laccaria (Hydnangiaceae, Agaricales) plays an important role in forest ecosystems as an ectomycorrhizal fungus, contributing to nutrient cycles through symbiosis with many types of trees. Though understanding Laccaria diversity and distribution patterns, as well as its association with host plants, is fundamental to constructing a balanced plant diversity and conducting effective forest management, previous studies have not been effective in accurately investigating, as they relied heavily on specimen collection alone. To investigate the true diversity and distribution pattern of Laccaria species and determine their host types, we used four different approaches: specimen-based analysis, open database search (ODS), NGS analysis, and species-specific PCR (SSP). As a result, 14 Laccaria species have been confirmed in Korea. Results regarding the species distribution pattern were different between specimen-based analysis and SSP. However, when both were integrated, the exact distribution pattern of each Laccaria species was determined. In addition, the SSP revealed that many Laccaria species have a wide range of host types. This study shows that using these four different approaches is useful in determining the diversity, distribution, and host of ECM fungi. Furthermore, results obtained for Laccaria will serve as a baseline to help understand the role of ECM fungi in forest management in response to climate change.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1615-1634
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• 2004

A review was undertaken to obtain information on the sustainability of pig free-range production systems including the management, performance and health of pigs in the system. Modern outdoor rearing systems requires simple portable and flexible housing with low cost fencing. Local pig breeds and outdoor-adapted breeds for certain environment are generally more suitable for free-range systems. Free-range farms should be located in a low rainfall area and paddocks should be relatively flat, with light topsoil overlying free-draining subsoil with the absence of sharp stones that can cause foot damage. Huts or shelters are crucial for protecting pigs from direct sun burn and heat stress, especially when shade from trees and other facilities is not available. Pigs commonly graze on strip pastures and are rotated between paddocks. The zones of thermal comfort for the sow and piglet differ markedly; between 12-22$^{\circ}C$ for the sow and 30-37$^{\circ}C$ for piglets. Offering wallows for free-range pigs meets their behavioural requirements, and also overcomes the effects of high ambient temperatures on feed intake. Pigs can increase their evaporative heat loss via an increase in the proportion of wet skin by using a wallow, or through water drips and spray. Mud from wallows can also coat the skin of pigs, preventing sunburn. Under grazing conditions, it is difficult to control the fibre intake of pigs although a high energy, low fibre diet can be used. In some countries outdoor sows are fitted with nose rings to prevent them from uprooting the grass. This reduces nutrient leaching of the land due to less rooting. In general, free-range pigs have a higher mortality compared to intensively housed pigs. Many factors can contribute to the death of the piglet including crushing, disease, heat stress and poor nutrition. With successful management, free-range pigs can have similar production to door pigs, although the growth rate of the litters is affected by season. Piglets grow quicker indoors during the cold season compared to outdoor systems. Pigs reared outdoors show calmer behaviour. Aggressive interactions during feeding are lower compared to indoor pigs while outdoor sows are more active than indoor sows. Outdoor pigs have a higher parasite burden, which increases the nutrient requirement for maintenance and reduces their feed utilization efficiency. Parasite infections in free-range pigs also risks the image of free-range pork as a clean and safe product. Diseases can be controlled to a certain degree by grazing management. Frequent rotation is required although most farmers are keeping their pigs for a longer period before rotating. The concept of using pasture species to minimise nematode infections in grazing pigs looks promising. Plants that can be grown locally and used as part of the normal feeding regime are most likely to be acceptable to farmers, particularly organic farmers. However, one of the key concerns from the public for free-range pig production system is the impact on the environment. In the past, the pigs were held in the same paddock at a high stocking rate, which resulted in damage to the vegetation, nutrient loading in the soil, nitrate leaching and gas emission. To avoid this, outdoor pigs should be integrated in the cropping pasture system, the stock should be mobile and stocking rate related to the amount of feed given to the animals.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.225-230
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• 2006

Tomatoes were experimented in perlite bags for various irrigation control methods to elucidate the efficient method for nutrient solution management. The irrigation control methods were for 3 different types such as control by drainage level sensor (PROBE), control by integrated solar radiation (ISR), and control by time clock (Timer). The substrate weight was maintained stably in the proper range in PROBE treatment, regardless of daily solar radiations or growth stages. The bed weights in the treatments of ISR and Timer were changed largely. Growth as well as total yield was the highest in PROBE treatment. There was no difference in soluble solids (Brix %) among the treatments. Consequently, ISR control could be useful only with appropriate timer control and also calibration. Control by drainage level sensor was suggested to be the most satisfactory as irrigation management method.

• Korean Journal of Ecology and Environment
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• v.47 no.1
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• pp.62-69
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• 2014

Standing crop distribution of aquatic plants in the West Nakdong River and riparian wetlands in the Nakdong River were surveyed in May, July and September, 2010. Total 25 aquatic macrophyte species (submerged: 9, leaf-floating: 3, free-floating: 5, emergent: 8) were observed during the survey periods. Distribution area of aquatic plants and proportion of submerged communities were highest in Garakchi-deung ($212,032m^2$, 72.7%). The distribution area of aquatic plants was highest in Phragmites australis community ($421,584m^2$), followed by Hydrilla verticillata-Vallisneria natans community ($181,511m^2$), Potamogeton wrightii-Vallisneria natans community ($61,604m^2$), and Hydrocharis dubia community ($49,709m^2$). Garakch-ideung (212,032 kg) also had the highest aquatic plant production, followed by Suanchi-deung (15,546 kg), Daedong (5,813 kg), Dunchi-do (3,963 kg), Maekdo (1,463 kg), Yeommak (571 kg), Jungsa-do (530 kg), and Shinan (300 kg). Average standing crop of the study area were $147.8{\pm}20.8g\;DW{\cdot}m^{-2}$ in 1988, $96.1{\pm}20.0g\;DW{\cdot}m^{-2}$ in 2000, and $172.6{\pm}76.1g\;DW{\cdot}m^{-2}$ in 2010. For a sustainable management of river habitat and food source, aquatic plant should concurrently be surveyed with river environmental variables (i.e. sediment, nutrient, flow).

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.2
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• pp.216-224
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• 2009

In Japan, since rice consumption has been decreasing with the westernization of Japanese eating habits, surplus paddy fields have been increasing. If these surplus paddy fields can be utilized for forage rice production as feed for animal production and excretions (feces and urine) from animal production can be applied to the paddy fields as manure, then the problems of surplus paddy fields and excretions from animal production may be solved, and the environment kept sustainable. The objectives of the present study were to apply a bio-economic model to dairy and forage rice integration systems in Japan and to examine the merit of introducing whole crop rice silage (WCRS), as well as economic and environmental effects of various economic and management options in the systems. Five simulations were conducted using this model. The use of WCRS as a home-grown feed increased environmental loads and decreased economic benefit because of the higher amount of purchased feed, when compared to the use of typical crops such as maize, alfalfa and timothy silage (simulation 1). Higher economic benefits from higher forage rice yields and higher milk production of a dairy cow were obtained (simulations 2, 3). There were no economic and environmental incentives for utilizing crude protein (CP) rich WCRS, because an increase in the CP content in WCRS led to the use of more chemical fertilizers, resulting in high production costs and nitrogen outputs (simulation 4). When evaluated under the situation of a fixed herd size, increasing forage rice yields decreased the total benefit of the production, in spite of the fact that the amount of subsidies per unit of land increased (simulation 5). It was indicated that excess subsidy support may not promote yield of forage rice. It was, however, observed in most cases that dairy and forage rice integration systems could not be economically established without subsidies.

• Journal of Environmental Science International
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• v.33 no.1
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• pp.17-25
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• 2024

This study aimed to determine the most suitable coir substrate mixing ratio for optimizing the growth and yield of the "lpduelkkae 1" cultivar. We comprehensively analyzed the physicochemical properties, growth, and yields of four different substrate combinations: perlite (coir with mixing ratios of 70:30 (PC30), 50:50 (PC50), and 30:70 (PC70)) and 100% coir (C100). The results revealed substantial differences in substrate properties. C100 exhibited the highest total porosity and the lowest solid phase, indicating excellent air permeability. The pH levels and electrical conductivity (EC) values ranged from 5.4-6.8 and 1.2-3.1 dS·m^-1, respectively. Leaf growth parameters, including length, width, and dry weight, showed positive correlations with high coir ratios, except for PC30. PC70 and C100 outperformed other substrates in stem growth, exhibiting superior stem diameter and fresh and dry weights. The quantity of marketable leaves was the highest in the C100 substrate. Furthermore, C100 comprised integrated levels of essential nutrients, such as Ca and Mg, owing to its high coir content. In conclusion, a coir ratio of approximately 70% (v/v) should be maintained in the substrate for creating an optimal cultivation environment. Furthermore, the selection of humidity-resistant varieties as well as precise nutrient and moisture management for different seasons and growth stages are crucial for a successful perilla leaf hydroponic cultivation.

• The Journal of the Korea Contents Association
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• v.16 no.10
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• pp.435-442
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• 2016

Obesity extends the global economic burden and it causes that the failure of a reduction of physical activity, and diet management. In this work, nutritional information and personalized diet based on calorie supply system and is discriminatory utilized the obesity-related SNP information in order to recommend a personalized functional foods. This study performed a GWAS analysis for the excavation of a Korean-specific and obesity-related SNP, which utilizes genetic information were recommended by entering a personalized diet in accordance with the SNP genotype-phenotype information. In addition, we integrated Database with relation of nutrient for utilizing the USDA Food information and it was applied to recommend with Sickdanome. As a result, the obesity-related SNP information was confirmed in the sample which has the normal value BMI. In this study, we have recognized that the phenotype information related obesity, BMI is inconsistent with the SNP genotype information. This result is shown that it is necessary to provide the personalized dietary SickdanOme recommendation based on the both pheotype-genotype information.

• Journal of Korea Water Resources Association
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• v.45 no.12
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• pp.1293-1307
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• 2012

This study is to evaluate the RHESSys (Regional Hydro-Ecological Simulation System) simulated streamflow (Q), evapotranspiration (ET), soil moisture (SM), gross primary productivity (GPP) and photosynthetic productivity (PSNnet) with the measured data. The RHESSys is a hydro-ecological model designed to simulate integrated water, carbon, and nutrient cycling and transport over spatially variable terrain. A 8.5 $km^2$ Seolma-cheon catchment located in the northwest of South Korea was adopted. The catchment covers 90.0% forest and the dominant soil is sandy loam. The model was calibrated with 2 years (2007-2008) daily Q at the watershed outlet and MODIS (Moderate Resolution Imaging Spectroradiometer) GPP, PSNnet and 3 year (2007～2009) daily ET data measured at flux tower using the eddy-covariance technique. The coefficient of determination ($R^2$) and the Nash-Sutcliffe model efficiency (ME) for Q were 0.74 and 0.63, and the average $R^2$ for ET and GPP were 0.54 and 0.93 respectively. The model was validated with 1 year (2009) Q and GPP. The $R^2$ and the ME for Q were 0.92 and 0.84, the $R^2$ for GPP were 0.93.