• 한국토양비료학회지
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• 제47권5호
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• pp.332-339
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• 2014

This research was performed to test the hypothesis that the optimal fertilization rate for red pepper is changed by soil moisture condition. The experiment was conducted in rainfall-intercepted fields in Suwon, South Korea from 2002 to 2003. Soil was irrigated at 30, 50, or 80 kPa of soil moisture tension at 20 cm soil depth in 2002 and 30, 50, 100, or 150 kPa in 2003. For both years, fertilization was performed with four levels: none, 0.5, 1, and 1.5 times of the recommended N, P, and K fertilization rate. The irrigation amount was the greatest at 30 kPa irrigation while the water use efficiency increased with decrease of irrigation amount. The Irrigation amount was 508 mm at 30 kPa irrigation and ranged from 355 mm to 435 mm at 50 kPa irrigation. The maximum yield was found at 30 kPa irrigation and 1.5 times of the recommend fertilization rate in 2002 and 2003. The yield index of red pepper increased linearly with the fertilization rate at 30 kPa which implied that excess irrigation induced nutrient leaching and reduced nutrient availability. The maximum yield in 50 kPa and 80 kPa was found at the recommend fertilization rate while the yield decreased by fertilization at 100 kPa and 150 kPa irrigation. It implies that reduction of fertilization is the feasible practice to mitigate drought stress in fields without stable irrigation resources.

• 한국토양비료학회지
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• 제50권1호
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• pp.31-39
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• 2017

The effects of application of gypsum and fresh cattle manure on the yield of forage crop were investigated in Hwaong reclaimed land in Korea for 3 years from 2011 to 2013. This study was conducted to develop the practical application method of livestock manure as a fertilization source and a soil physico-chemical ameliorator for the cultivation of forage crop $Sorghum{\times}Sudangrass$ hybrid in newly reclaimed tidal land soil. Treatments with six applications were established with three replications; chemical fertilizer (CF), gypsum (G) $20Mg\;ha^{-1}$, G+fresh cattle manure (FCM) 100%, G+FCM 200%, G+FCM 300% and FCM 100% which referred to the application rate equivalent to the recommended amount of phosphate fertilization by soil test. The combined treatments of G+FCM increased soil organic matter, $Av.P_2O_5$ and exchangeable $Ca^{2+}$ contents while decreased exchangeable $Na^+$ and $Mg^{2+}$. The soil bulk density, soil hardness and soil aggregate formation were improved by G+FCM treatments. The dry matter yields of $Sorghum{\times}Sudangrass$ hybrid were significantly increased in proportion to the application rate of FCM. The phosphorus use efficiency showed the highest in the application level of G+FCM 100%, which seemed to be the results of reduced nutrient use efficiency by nutrient immobilization, leaching etc. when applied excessive amount of fresh animal manure.

• 한국농림기상학회지
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• 제4권4호
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• pp.237-247
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• 2002

Air pollution by acid pollutants is problematic in the whole world. Water acidification has already been deteriorating the forest ecosystem. This study was conducted to analyze the acidity and chemical composition of the open precipitation and throughfall at forests with various geographic locations in Korea. The results of this study are as follows; The open precipitation pH was lowest in Seochun. The throughfall pH showed some buffering capacity in only Quercus mongolica stands. In Pinus rigida(Shingal and Seochun) stands, there was little difference from the open precipitation. Chemical composition of the open precipitation for each sampling site showed that $Ca^{2+}$, N $H_{4}$$^{+}$ and S $O_{4}$$^{2-}$ concentrations had higher value than other ions, and except these ions, the small quantity of ions showed different properties to each site. Changes of ion concentrations in the throughfall showed a tendency to increase. ion concentrations of the throughfall increased with washout and nutrient leaching from the trees. In conclusion, the influence was extended to the pure zone, and the frequency of acid rain is increasing. But, if the deposition of pollutants exceeds the capacity of purification, it would damage forest ecosystem. Further investigations are necessary to identify tolerant tree species to acid pollutants.nts.

• 한국토양비료학회지
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• 제44권1호
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• pp.78-83
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• 2011

Phosphorus (P) which is required by all living plants and animals is an important input for economic crop and livestock production systems. Phosphorus containing compounds are essential for photosynthesis in plants, for energy transformations and for the activity of some hormones in both plants and animals. Loss of soil P to water can occur in particulate forms of P with eroded surface soil and in soluble forms in runoff, soil interflow, and deep leaching. The excessive losses of P from agricultural systems can degrade water quality of surface waters, resulting in accelerating eutrophication. Thus, P is often the limiting element and its control is of prime importance in reducing the accelerated eutrophication of surface waters. However, reserves of phosphate begin to run out, the impacts are likely be immense in terms of rising food prices, growing food insecurity. This paper reviews underappreciated resource as a key component of fertilizers and one of controversial pollutant in terms agronomy and environment.

• 한국식품영양학회지
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• 제24권3호
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• pp.464-470
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• 2011

Thermally processed vegetables have long been considered to have lower nutritional values compared to fresh produce. This consideration is based on the fact that ascorbic acid(vitamin C) or other thermolabile compounds may lose their activity due to oxidation or by consequence of leaching into the water during home cooking or industrial processing, such as by blanching. In this study, major agricultural products such as carrots, broccoli, and potatoes were exposed to steam treatments of different types. Then, changes in color and levels of ascorbic acid, carotene, and moisture in the fresh and steam processed vegetable samples were measured and evaluated. The results clearly showed that steam-processing using a natural convection type method was superior to the other treatments in terms of quality, including color and nutrient retention, among all the vegetables tested.

• 한국농공학회논문집
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• 제52권3호
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• pp.65-71
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• 2010

This study was conducted to investigate the dynamics of nutrients such as total nitrogen (TN), nitrate nitrogen ($NO_3$-N) total phosphorous (TP), and phosphate phosphorous ($PO_4$-P) in outflow from a cabbage farmland in a mixed land-use watershed. The TN concentrations in groundwater showed twice peaks in late July 2006 and late March 2007 (3.8, 4.7 mg/L, respectively), when it rained shortly after fertilizer application, indicating that nitrogen leaching is greatly influenced by fertilization and rainfall. The mean concentrations of TN and $NO_3$-N in surface water were not significantly higher than those in groundwater, while the mean concentrations of TP and $PO_4$-P in surface water were significantly (p < 0.05) were higher than those in groundwater. The TN concentrations in groundwater were generally higher than those in surface water during fertilization and early growing season due to the effect of fertilization, but vice versa in the other periods. In contrast, the TP concentrations in groundwater were always lower than those in surface water due to the sorption of particulate phosphorous by soil. The ratio of TN load in baseflow to that in total TN load (39 %) was much greater than the TP ratio (7 %), suggesting that baseflow contribute to nitrogen export. Therefore, proper fertilization management should be taken to reduce nitrogen load through baseflow.

• 한국지하수토양환경학회지:지하수토양환경
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• 제17권4호
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• pp.27-35
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• 2012

Recently, there has been increasing interest in the use of rain garden systems as environmentally friendly ecological infrastructures for controlling stormwater runoff and managing non-point source pollution and information for the contamination of soil and plants can be essential for sustainable rain garden management. In this study, four rain garden mesocosms, namely single species planting with Rhododendron lateritium, single species planting with Zoysia japonica, mixed planting with R. lateritium and Z. japonica, and control without plants, were tested to investigate the change in concentrations of nutrients (N and P) and heavy metals (Cd, Cu, Pb, and Ni) in the soil and plants used in the rain garden system. The presence of plants resulted in greater nutrient retention in soil and lower potential leaching from the system. All systems showed an increase in the heavy metal concentrations in soil. The concentrations of most heavy metals were found to be higher in the herbaceous plants (Z. japonica) than in the shrubs (R. lateritium). The belowground part (root) had higher heavy metal concentrations than the aboveground part (leaf) but also showed a potential increase in leaves, and hence, careful plant management should be considered during rain garden operation.

• 한국기계가공학회지
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• 제18권2호
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• pp.44-51
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• 2019

With the goal of tissue regeneration for organs damaged through an accident or a disease, research on tissue engineering has been conducted to produce 3-D scaffolds that can support the cells in the attachment and growth for the cell proliferation and differentiation. A scaffold requires a suitable pore size and porosity to increase the nutrient circulation or oxygen supply for the attachment and growth of cells. The existing production methods such as solvent-casting particulate leaching, phase separation, and fiber bonding have certain disadvantages. With these methods, it is difficult to obtain a free desired shape. In addition, certain pore sizes and interconnectivities among the pores may not be guaranteed. To solve these problems, this study has fabricated a scaffold with a 3-D shaped nose using Alginate, which is a natural polymer obtained through Fused Deposition Modeling (FDM), one of the CAD/CAM-based Solid Freeform Fabrication (SFF) methods.

• 한국산림과학회지
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• 제87권4호
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• pp.611-619
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• 1998

황산용액을 첨가하여 인위적으로 산성화시킨 갈색산림토양에 2년생 소나무 묘목을 온실내에서 120일 동안 생육시킨 후, 묘목의 생장과 영양상태를 조사하였다. 토양용액의 Al 농도는 토양의 $H^+$ 부하량이 증가함에 따라 증가하였으며, 또한 소나무 묘목의 건물생장은 토양의 $H^+$ 부하량이 증가함에 따라 감소하였다. 소나무 묘목 지하부 Al 농도의 증가는 엽내 Ca 및 Mg 등과 같은 식물생장 필수원소 농도의 저하를 초래하였다. 소나무 묘목의 건물생장과 토양용액의 (Ca+Mg+K)/Al 몰비와의 사이에 높은 상관이 있는 것으로 나타났으며(r=0.96, p<0.001), 토양용액의 (Ca+Mg+K)/Al 몰비가 7.0이하로 낮아지면 건물생장이 감소가 발생하고 몰비가 1.0일 때의 건물생장은 대조구에 비하여 약 40% 감소하였다. 이상의 결과를 종합할 때 토양용액의 (Ca+Mg+K)/Al 몰비의 이용은 산성강하물에 대한 임계부하량 평가에 중요한 지표(指標)가 될 수 있다고 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권11호
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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.