• Korean Journal of Environmental Agriculture
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• v.37 no.3
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• pp.160-165
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• 2018

BACKGROUND: Mixed cropping of legume and grass was effective system in view point of providing organic matter and nitrogen or reducing the nitrogen starvation of following crop. The relation of the change of N and P constituents depending on the cropping types and those effects on the growth and nutrient uptake of the following crop were observed. METHODS AND RESULTS: Three cropping types, hairy vetch mono cropping, barley mono cropping, and mixed cropping of hairy vetch and barley were applied. Soil properties, growth characteristics, and nitrogen production of green manure crops were observed. In additions, the effect of cropping types on the growth pattern of corn as the following crop was observed. In the mixed cropping system, creeping type hairy vetch climbed to the erect type barely for light utilization resulting in improvement of light interception rate and higher LAI (Leaf Area Index) than in mono cropping. Mixed cropping showed higher biomass production and soil nitrogen availability among the cropping types, indicating relatively much more nutrient supply and higher yield production of following crop. CONCLUSION: Mixed cropping showed relatively higher LAI (dry matter) mainly because of intense competition for light utilization usually after flowering stage. Mixed cropping also showed relatively higher yield of corn, the following crop rather than other types, mainly due to the more biomass production potential and higher N and P production ability. Therefore, mixed cropping was adaptable method to reduce or replace chemical fertilizer application for environmentally-friendly agriculture.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.1
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• pp.67-77
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• 2011

Heavy metal remediation in shooting range soil is a challenge over the world. The excessive Pb accumulation in the soil can deteriorate soil quality and fertility. The objectives of this research were to evaluate the efficiency of biochar (BC) in improving the physicochemical and biological properties of the soil and to evaluate its effect on Pb availability in a military shooting range soil. Sandy loam soil was collected from shooting range of Gyeonggi Province, South Korea and was incubated for 30 days with different application rates (0-30% w $w^{-1}$) of BC. The results showed that the addition of BC increased aggregate stability, nitrogen (N) and phosphorus (P) contents, and enzyme activities in soil. Sequential extraction showed that residual and organic bound fractions in the soil amended with BC increased by 33.1 and 16.7%, respectively, and the exchangeable fraction decreased by 93.7% in the soil amended with BC, compared to the unamended soil. We concluded that the application of BC could not only improve physicochemical and biological soil qualities but also stabilize Pb in a shooting range soil.

• ALGAE
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• v.24 no.3
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• pp.139-147
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• 2009

Microalgae using a submersible fluorescence probe in water column (up to 100 m) were measured during the austral summer of 2006 (February) in Prydz Bay, East Antarctica (triangular-shaped embayment in the Indian sector of Southern Ocean). Concurrently, environmental parameters such as temperature, salinity and nitrogen (nitrate, ammonium, urea) uptake rates were measured. The concentration of phytoplankton is relatively high due to availability of high nutrients and low sea surface temperature. Phytoplankton community is dominated by diatoms whereas cryptophytes are in low concentration. The maximum concentration of total chlorophyll is 14.87 ${\mu}g\;L^{-1}$ and is attributed to upwelled subsurface winter water due to local wind forcing, availability of micro-nutrients and increased attenuation of photosynthetically available radiation (PAR). Concentration of blue-green algae is low compared to that of green algae because of low temperature. Comparatively high concentration of yellow substances is due to the influence of Antarctic melt-water whereas cryptophytes are low due to high salinity and mixed water column. Varied concentrations of phytoplankton at different times of Fluoroprobe measurements suggest that the coastal waters of Prydz Bay are influenced by changing sub-surface water temperature and salinity due to subsurface upwelling induced by local winds as also melting/freezing processes in late summer. The productivity is high in coastal water due to the input of macro as well as micro-nutrients.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.169-176
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• 1985

Six analytial methods for determing the available nitrogen in soils were tested to predict the optimum fertilizer rate for the flue-cured tobacco and to test the fertility level of soils for tobacco. All methods, nitrifiable $NO_3-N$ value for 2 and 4 weeks incubation, UV absorption value at 260nm and N-value in acid digestion of 0.01 M-$NaHCO_3$ extracts, N-value extracted in boiling with $CaCl_2$ solution, and autoclave-extractable $NH_4-N$ value in 0.01 M-$CaCl_2$, were closely correlated with total nitrogen uptake as well as yield. Therefore available nitrogen indices determined from above 6 analysis method could be used for the predicting of tobacco yield without fertilizer, criteria for fertility class, and recommendable range of optimum fertilization.

• Korean Journal of Food Science and Technology
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• v.4 no.2
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• pp.106-111
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• 1972

The possibility of substituting raw materials for soy sauce by corn gluten was studied by measuring the amylase and proteolytic activities of koji. Also optimum conditions of koji making were determined. It was found that substitution of up to 30% of the defatted bean content (or 15% of the total bean and wheat content) with corn gluten yielded a good quality of soy sauce. Use of more than 15% corn gluten (based on total bean and wheat content) yielded a soy sauce of poor taste and low nitrogen content even though corn gluten has a high nitrogen content. This drop in nitrogen was attributed to the low enzyme activity in koji containing more than 15% corn gluten and the difference in availability of nitrogen in bean compared to corn gluten.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.404-412
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• 2015

The slurry composting and bio-filtration (SCB) liquid manure has some obvious advantages including a good source of N, P and K, local availability, effective microorganism and the ability to improve soil properties. This study was conducted to evaluate the influence on the changes of soil chemical properties and yield of red pepper by fertigation cultivation with SCB application for 2 years. Red pepper was transplanted in early May in 2013 and 2014. The treatment with three replication was composed of 4 types as control (N 1.0), SCB 0.5N, SCB 1.0N, and SCB 2.0N standards of recommended nitrogen fertilizer ($19kg\;N\;10a^{-1}$). The fertigation cultivation which was installed the surface drip irrigation system was splitted 10 times as $2.5Mg\;10a^{-1}$ nutritional solution included with chemical fertilizer and SCB every 10 days during the cultivation. The height and width of pepper plant were 7.0% and 5.8% higher in SCB 2.0N treatment than that in control. The yield of red pepper increased with the increasing of SCB application rates from SCB 0.5N to 2.0N. The yield of SCB 1.0N was much better 10% in average than that of control, and there was significant differences among all treatments. pH of control soil after final harvest decreased to 6.1, however pH of SCB treated soils increased from 6.7 to 7.1 depending on SCB application rates. The Exch.-K contents of SCB treated soils were increased 13.7 to 56.9% after final harvest compared with control by $0.51cmol_c\;kg^{-1}$. Accordingly, these results showed that SCB 1.0N application rate as a recommended nitrogen level based on soil testing can be used as an alternative nitrogen management as well as plant nutrition for red pepper cultivation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.212-219
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• 2016

The bioavailability of dissolved organic nitrogen (DON) by dominant species Chaetoceros debilis and Leptocylindrus danicus under dissolved inorganic nitrogen (DIN)-limited condition in the southwestern East Sea was conducted to assess the quantitative evaluation using growth kinetic experiment. Nitrogen sources were nitrate and ammonium as DIN, glycine and urea, which is portion component of DON in East Sea. Maximum specific growth rate (${\mu}_{max}$) and half-saturation constant ($K_s$) of C. debilis calculated from Monod equations were estimated to be $1.50day^{-1}$ and $1.62{\mu}M$ in nitrate, $1.13day^{-1}$ and $6.97{\mu}M$ in ammonium, $1.46day^{-1}$ and $3.36{\mu}M$ in glycine, $0.93day^{-1}$ and $0.55{\mu}M$ in urea, respectively. Also, L. danics was estimated to be $1.55day^{-1}$ and $5.21{\mu}M$ in nitrate, $1.57day^{-1}$ and $4.57{\mu}M$ in ammonium, $1.47day^{-1}$ and $3.80{\mu}M$ in glycine, $1.42day^{-1}$ and $1.94{\mu}M$ in urea, respectively. Both C. debilis and L. dancius have higher affinity of urea than DIN. The high affinity of urea was indicated that the dominant species were able to growth using urea under DIN-limited conditions. Thus, DON utilization of phytoplankton may be one of the important dominant strategy under DIN-limited environments such as southwestern East Sea.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.8
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• pp.1089-1101
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• 2013

Effects of varied dietary energy densities on immune response and performance of Muzzafarnagari lambs were ascertained in a 180-d study. Animals (n = 24), in three groups, were fed diets providing 100% (100E), 80% (80E) or 70% (70E) of their metabolizable energy requirement. Mean nutrient digestibilities varied significantly among treatments. Nitrogen intake was lower (p<0.01) in the 70E. Nitrogen retention, was reduced (p<0.001) in 80E and 70E vs 100E. The average daily gain (p<0.001) was $47.01{\pm}4.23$, $13.54{\pm}1.72$ and $-16.67{\pm}8.24$ g for 100E, 80E and 70E, respectively. Hemoglobin concentration, haematocrit, total and differential leukocyte counts were lower (p<0.001) for 80E and 70E than for 100E with a similar trend (p<0.05) for serum glucose and total protein. Serum cortisol was reduced (p<0.001) with decreased energy availability. Antibody titre to Brucella abortus S19 showed an initial reduction in 80E and 70E vs 100E. Delayed-type hypersensitivity response was lower (p<0.001) in 80E and 70E vs 100E, accompanying a lower (p<0.001) nitric oxide production by the peripheral lymphocytes. It is concluded that the reduced dietary energy density significantly affects the growth performance and immune response of lambs.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.571-582
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• 1992

Soybeans were dry extruded at three different temperatures (125, 135 and $145^{\circ}C$) for 30 s. Four lambs fitted with cannulae in the rumen and abomasums were used in a balanced $4{\times}4$ Latin square design. Lambs were fed at 2 h intervals for 12 times a day with automatic feeder to maintain steady state conditions in digestive tract. A dual-phase marker system was used to estivate ruminal flow rate of both liquid and solid digesta. Objectives of this study were to determine the effect of extrusion temperature of raw soybean on the ruminal liquid and solid dilution rate, nitrogen digestion and flow at the abomasum and availability of amino acid in lambs. There were no significant effects of extrusion on liquid and solid dilution rate, and liquid volume. Ruminal liquid flow rate was not influenced by extrusion and ranged from 389 to 435 ml/hr. Extrusion had no influence on ruminal OM digestion and flow rate to the abomasums. Dietary N flow to the abomasums increased (p < 0.05) as extruding temperature increased. Extruding temperature had a significant effect (p < 0.05) on flow of N escaping ruminal degradation and ranged from 34.91 to 57.38%. Microbial N synthesized/kg OMTDR ranged from 27 to 37 g and highest with $145^{\circ}C$ ESB diet. Extrusion decreased the amount of degradable amino acid in the rumen and increased the supply of amino acid to the lower gut, especially with 135 and $145^{\circ}C$ ESB diets.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.365-372
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• 2013

Crop development and nutrient availability are strongly influenced by soil salinity levels. This study was conducted to investigate the effect of rice straw and nitrogen (N) fertilizer for silage barley under various soil salinity levels at Saemangeum reclaimed tidal land. Three levels of rice straw (0, 2.5, 5.0 ton rice straw $ha^{-1}$) and N (0, 150, 225 kg N $ha^{-1}$) were applied at 0.04, 0.23, 0.35% soil salinity levels. Biomass yield of silage barley was influenced by the interactions between rice straw application and N fertilization. Although there was no single effect of rice straw application on biomass yield, it was significantly increased with N application and a rice straw application of 5.0 ton $ha^{-1}$. Sodium content in silage barley was significantly lower at 0.04% salinity level, and but it was statistically increased with increasing soil salinity levels. Forage qualities such as total digestible nutrients and relative feed value of silage barley were significantly higher with N application at 0.04% salinity level, but there was no effect of rice straw application. Soil organic matter content was increased with N and rice straw application regardless of soil salinity level. The results of this study showed that the effect of rice straw and N fertilization on silage barley was influenced by soil salinity levels, which indicates that the management practice of silage barley at Saemangeum reclaimed tidal land should consider soil salinity levels.