• Journal of The Korean Society of Agricultural Engineers
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• v.59 no.4
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• pp.27-42
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• 2017

The global rise in atmospheric $CO_2$ concentration and its associated climate change have significant effects on agricultural productivity and hydrological cycle. For food security and agricultural water resources planning, it is critical to investigate the impact of climate change on changes in agricultural productivity and water consumption. APEX-Paddy model, which is the modified version of APEX (Agricultural Policy/Environmental eXtender) model for paddy ecosystem, was used to evaluate rice productivity and evapotranspiration based on climate change scenario. Two study areas (Gimjae, Icheon) were selected and the input dataset was obtained from the literature. RCP (Representitive Concentration Pathways) based climate change scenarios were provided by KMA (Korean Meteorological Administration). Rice yield data from 1997 to 2015 were used to validate APEX-Paddy model. The effects of climate change were evaluated at a 30-year interval, such as the 1990s (historical, 1976~2005), the 2025s (2011~2040), the 2055s (2041~2070), and the 2085s (2071~2100). Climate change scenarios showed that the overall evapotranspiration in the 2085s reduced from 10.5 % to 16.3 %. The evaporations were reduced from 15.6 % to 21.7 % due to shortend growth period, the transpirations were reduced from 0.0% to 24.2 % due to increased $CO_2$ concentration and shortend growth period. In case of rice yield, in the 2085s were reduced from 6.0% to 25.0 % compared with the ones in the 1990s. The findings of this study would play a significant role as the basics for evaluating the vulnerability of paddy rice productivity and water management plan against climate change.

• Journal of Bio-Environment Control
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• v.18 no.3
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• pp.253-257
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• 2009

To analysis effect of environment factors on productivity of sweet pepper according to greenhouse covering material (glass, plastic film), this was investigated. In glasshouse, outside light was positively correlated with yield as that $100MJ{\cdot}m^{-2}$ of outside light increased $300{\sim}500g{\cdot}m^{-2}$, also cumulative temperature was same tendency. On possibility of model development for yield estimate cumulative temperature was high than outside light. According to covering material, leaf photosynthesis, productivity per out-side light and term in glasshouse was more high 13%, 46%, and 47% compared with plastic film house, respectively. Result of analysis of effect of light, temperature, and $CO_2$ on yield, relative yield coefficient, yield increment coefficient, and yield reduction coefficient in glasshouse were more high 25%, 73%, and 34% compared with plastic film house, respectively. Hence, sweet pepper's growing in glasshouse compare with plastic film house had more productivity, but that had more sensitivity to charge of environment factors.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.3
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• pp.213-217
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• 1995

Leucaena leucocephala (lam. de Wit) is a multipurpose leguminous tree/shrub, promoted extensively for reforestation and rural development programmes, as well as in ruminant production. After a year of establishment in the plots, the overall leaves and twigs yield was on average 0.92 kg/plant, containing an average 23.34, 10.61, 5.32 and 10.13 percent CP, CF, and ash, respectively. The proximate and mineral compositions are affected by factors such as stage of maturity, type of cultivar, seasons, cutting intervals, different plant parts. Though leucaena contains toxic mimosine and tannins, these are not always deleterious for ruminants and rumen microbes can often degrade toxic factors into a nontoxic utilizable product Mimosine content is generally higher in the seed than other plant parts. Leucaena supplementation in ruminant ration showed higher digestibility co-efficient of proximate component, which may results in higher productivity. Considering its productivity, composition and nutritive value. L. Leucocephala could be more widely used as a protein source for ruminants in tropical and sub-tropical countries.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.381-384
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• 2006

This study was conducted to selected Korean black raspberry (Rubus coreanus Miq.) for high productivity. The eight major agronomic traits were investigated from 198 clones of the clone bank established in Korea Forest Research Institute, Suwon, Korea. The selection levels based on number of fruit per fructify lateral (NFFL) over 20, and fruit weight (FW) over 1.3g, and yield of individual per fructify lateral (YIFL) over 25g, were applied on 198 clones, resulted in 17 clones selected. The selected superior trees, 17 clones, appeared regional differences for amount of fruiting among 4 different test sites. When number of fruit per fruit petiole (NRFP), fruit weight (FW), yield of individual (YI) and sugar content were satisfied over 20, 1.4g, 6kg and 9.5 brix, respectively, as a select condition, 5 clones were reselected as the superior trees among 17 clones. for 3 years.

• The Journal of Engineering Geology
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• v.9 no.2
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• pp.101-118
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• 1999

The pumping test analysis on 28 pumping test data in Duksan hot-spring area was performed using the fractal model, the leaky fractal model, and the steady-state dual-porosity fractal model. The fractional flow dimension 1.9 or 2.0 was determined in the central put of the hot spring and the fractional flow dimension 1.5-1.7 in the marginal area. For the flow dimension 2.0, the correlation between the transmissivity and the productivity index by the aquifer loss was much better than that between the transmissivity and the specific yield by the total drawdown. On the other hand, for the flow dimension 1.9, the correlation between the generalized transmissivity and the productivity index was very similar to that between the generalized transmissivity and the specific yield.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.644-648
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• 2001

The biological control potential of entomopathogenic nematodes (EPN) can be enhanced by improved culture efficiency. Optimization of the media is a key factor for improving in vitro mass production of entomopathogenic nematodes. This study reports the effect of medium concentration. The medium is a combination of carbohydrates, lipids, proteins, sats, and growth factors, on the growth of Heterorhabditis bacteriophora and its symbiotic bacterium Photorhabdus liminescens. The overall optimal medium concentration for nematode recovery, hermaphrodite size, bacterial mass, infective juveniles (IJs) yield, and doubling time was 84 g/l. At this concentration rate, the doubling time of IJs production and the biomass of symbiotic bacteria was 1.6 days and 12.8 g/l, respectively. The maximum yield of $2.4{\times}{10^5}IJs/ml$ was attained within a one-generation cycle (eight days). The yield coefficient was $2.8{\times}{10^6}$ IJs/g medium, and the maximum productivity was $3.1{\times}{10^7}$ IJs per day. Medium concentration affected two independent factors, recovery and hermaphrodite size, which in turn influenced the final yield.

• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.164-171
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• 1999

Tomato yield and harvest date were analyzed to examine the productivity of Single Truss Tomato Production System(STTPS) for four regions in Korea. It was found that the solar radiation was not sufficient to get the maximum tomato yield during the low light seasons. The difference of total annual yield between Suwon and Jinju regions was about 12kg.m$^{-2}$ . These results indicate that supplemental lights are needed to increase the yield. The availability of natural light should be considered in deciding the locations of tomato greenhouses. The harvest date could be adjusted by using supplemental lighting. The development and implementation of the lighting control strategies are required for reducing electricity expense.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.3
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• pp.57-64
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• 2010

The impacts of climate change on yield and evapotranspiration of rice have been modeled using AquaCrop model developed by Food and Agriculture Organization (FAO). Climate change scenario downscaled by Mesoscale Model 5 (MM5) regional model from ECHO-G General Circulation Model (GCM) outputs by Korea Meteorological Research Institute (METRI) was used in this study. Monthly average climate data for baseline (1971-2000) and three time periods (2020s, 2050s and 2080s) were used as inputs to the AquaCrop model. The results showed that the evapotranspiration after transplanting was projected to increase by 4 % (2020s), 8 % (2050s) and 14 % (2080s), respectively, from the baseline value of 464 mm. The potential rice yield was 6.4 t/ha and water productivity was 1.4 kg/$m^3$ for the baseline. The potential rice yield was projected to increase by 23 % (2020s), 55 % (2050s), and 98 % (2080s), respectively, by the increased photosynthesis along with the $CO_2$ concentration increases. The water productivity was projected to increase by 19 % (2020s), 44 % (2050s), and 75 % (2080s), respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.75-81
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• 1997

This study was wnducte to investigate the effects of treatment level and seasons of sluny hm bovine feces on the productivity of rye, N efficiency and improvement of soil fertility under the Korean climate condition. The results obtained fiom this study summarized as follows ; 1. The highest dry matter yield of rye was obtained in the partial fertilization of sluny in spring or autumn. There is no differences of dry matter yield between spring and autumn application. 2. With increasing the amount of slurry-N, the dry matter yield of rye was signigicantly increased up to 100Kg sluny Nha. As the level of slurry-N rises above about 100Kg N/ha, the maximal yield of dry matter was unchanged or declined. 3. As the level of sluny fertilization rises, the crude protein content of rye increases significantly. However the contents of crude protein was less affected by the application seasons. 4. The amount of nitrogen which produced 6om rye is dependent upon the level of slurry-N. The highest nitrogen yield of rye was obtained by the partial fertilization of sluny-N. 5. The season or amount of slurry treatments did not affect the organic matter content in soil. N-content in soil was the lowest by the partial fertilization of slurry in spring or autumn. However, N-content was increased with the higher level of sluny-N.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.1-5
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• 2001

The potential use of spin filter device to retain Propionibacterium acidipropionici in the bioreactor under continuous mode of fermentation, and improve acid productivity, was examined. The yield of propionic acid based on lactose concentration was 51% in batch and 54% in continuous (dilution rate = 0.05 h(sup)-1) operation. The yield in continuous fermentation with cell retention using spin filter of 10 micron size (dilution rate = 0.05 h(sup)-1) was even higher at 70% (w/w). The volumetric productivity under batch and continuous mode of operation were 0.312g L(sup)-1 h(sup)-1 and 0.718g L(sup)-1 h(sup)-1 respectively. Continuous fermentation with cell retention demonstrated even higher volumetric productivities at 0.98g L(sup)-1 h(sup)-1 with out clogging problems. It could be used for utilization of cheese whey to produce propionic acid at higher yield and productivities.