• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.6
• /
• pp.1010-1015
• /
• 2011

The objectives of this study were to investigate soil chemical characteristics for forest rehabilitation and suggest management in abandoned coal mine areas in Hwasun-gun, South Jeolla Province. Total study sites were 8 sites, and soil analysis particular were soil pH, TOC, total-N, C/N ratio, Avail. $P_2O_5$, and CEC. Average soil pH was 5.8 (4.7~6.4). Average contents of TOC, total-N and C/N ratio were 1.1% (0.2~2.0%), 0.08% (0.02~0.13%) and 15.0 (7.9~31.4), respectively. Average Avail. $P_2O_5$ was $8.3mg\;kg^{-1}$ (2.7~15.0) and Average CEC was $13.7cmol_c\;kg^{-1}$ ($9.9{\sim}18.5cmol_c\;kg^{-1}$). Soil pH was decreased according to elapsed time from forest rehabilitation, while TOC, total N and CEC were increased. Av. $P_2O_5$ did not show any relationship with elapsed time. Soil pH was stable comparing with general forest soil in South Jeolla Province (5.1), while contents of TOC and total N were lower than general forest soil in South Jeolla Province (4.9% and 0.18%, respectively). Therefore, sustainable managements such as fertilization for TOC and total N are necessary for good rooting and growth of vegetation.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.6
• /
• pp.1130-1136
• /
• 2011

This study was carried out to determine the effects of pig slurry on growth of potato (Solanum tuberosum L. cv. Dejima), soil chemistry properties and infiltration water quality in volcanic ash soil and non-volcanic ash soil of Jeju. Fertilization of liquid pig manure was based on nitrogen. In volcanic ash soil and non-volcanic ash soil, there was no difference in the height and diameter of stems in chemical fertilizer and liquid pig manure application treatments. Also yields of potatoes were no significantly difference in chemical fertilizer and liquid pig manure application treatments. pH in all soil was increased by application of liquid pig manure compared to the chemical fertilizer plot. Contents of exchangeable K in all soil were accumulated excessively by fertilization of pig manure 100% compared to the chemical fertilizer 100%. But there was no difference between the chemical fertilizer 50%+liquid pig manure 50% and chemical fertilizer 100%. No difference between the chemical fertilizer and liquid pig manure was observed in available phosphate, exchangeable Ca and Mg. $NO_3$-N concentration of infiltration water sample collected at 70cm of soil depth was lower non-fertilizer than chemical fertilizer and liquid pig manure application treatments. In volcanic ash soil, the $NO_3$-N concentration of infiltration water was decreased from early, except liquid manure 100%. In non volcanic ash soil, the $NO_3$-N concentration of infiltration water increased until October 8, but then was reduced. In all soils, $NO_3$-N concentration of infiltration water was higher in the liquid manure 100% than those in the chemical fertilizer 100% and chemical fertilizer 50%+liquid pig manure 50%, but there were no differences. In conclusion, the growth of potato, fertilization of soil and $NO_3$-N content of infiltration water were not different between chemical 50%+liquid pig manure 50% and chemical 100% plot. So, liquid pig manure could be substituted for some amount of chemical fertilizer.

• Korean Journal of Soil Science and Fertilizer
• /
• v.40 no.1
• /
• pp.18-24
• /
• 2007

Paddy fields are apparently nonpoint source pollution and influence water environment. In order to improve water quality in rivers or lakes, to low nutrient load from paddy fields are required. To establish comprehensive plan to control agricultural non-point source pollution, it is imperative to get a quantitative evaluation on pollutants and pollution load from paddy fields. A field monitoring study was carried out to investigate the water balance and losses of nutrients from fields in Sumjin river basin. The size of paddy fields was 115 ha and the fields were irrigated from a pumping station. The observed total nitrogen loads from paddy fields were larger than those of the unit loads determined by Ministry of Environment data (MOE). It is because the nitrogen fertilization level at the studied field was higher than the recommended rate and the high irrigation and subsequent drainage amount. On the contrary, total phosphorus loads were less than those addressed by MOE since phosphorus fertilization level was lower than that of standard level. Therefore, it was found that fertilization, irrigation, and drainage management are key factors to determine nutrient losses from paddy fields. When the runoff losses of nutrients were compared to applied chemical fertilizer, it was found that 42 to 60% of nitrogen lost via runoff while runoff losses of phosphorus account for 1.3 to 7.6% of the total applied amount during the entire year.

• Korean Journal of Ichthyology
• /
• v.24 no.1
• /
• pp.1-10
• /
• 2012

Reciprocal hybrids between the mud loach ($Misgurnus$ $mizolepis$) and cyprinid loach ($M.$ $anguillicaudatus$) were produced by artificial fertilization. The chromosome number of mud loach was 2n=48, consisting of 12M+4SM+32A chromosomes. The cyprinid loach has 2n=50, consisting of 10M+4SM+36A chromosomes. The chromosome numbers of the diploid reciprocal hybrids were 2n=49, consisting of 11M+4SM+34A chromosomes. All the karyotypes documented in this study had the same arm number of 64. There was no evidence of chromosomal polymorphisms or sex-related heteromorphism. The cytogenetic traits of the hybrid genotypes were intermediate between those of the parent species. In all genotypes, the chromosomal NORs localized to the terminal short arms of the same metacentric chromosome pair. These results suggest that Robertsonian translocation occurred between metacentric chromosome 1 of mud loach and acrocentric chromosome of cyprinid loach.

• Korean Journal of Environment and Ecology
• /
• v.22 no.1
• /
• pp.59-65
• /
• 2008

This study is mainly focused on the mating of 9 couples of Eagle Owl Bubo bubo habitating in Paju, Ganghwa Island, Icheon, Sihwa Lake, Chungju. For this study, from 2005 to 2007, regular filming and mornitoring for the breeding ecology and copulation behavior of 9 couples of Eagle Owl in the nest and near area had been done. Clutches ranged in size from one to four eggs but averaged 2.27 eggs(n=15), hatching success rate was 71 %(n=34) and fledgling success rate was 83%(n=23). Through the filming and mornitoring, it was found that Eagle Owl continued to copulate each other even after hatching and kept its copulation until the chicks left their nest($7\sim8$ weeks after hatching). This copulation behaviour without fertilization seems to be done for confirming, maintaining and strengthening of pair-bond by the necessity of both male and female, and to aim at stable breeding of their chicks.

• Asian Journal of Turfgrass Science
• /
• v.2 no.1
• /
• pp.49-58
• /
• 1988

질소비료 3수준(0,350,700kg N-ha-1year-1) 및 예초간격 3수준( 10,20,30일 간격)하에서 이 요인들이 식물체 각부위(엽, 엽초를 포함한 차, 포복경 및 근)내, N,P,k,Ca,Mg 및 가용성 탄수화물함량에 여하히 영행을 미치는가게 대해서 1983년 6월부터 10일 까지 대전 배재대학실험포장에서 조성한지 3년 지난 한국잔디를 대상으로 실험하였던 바 결과는 다음과 같다. 1. 질소 증시한 결과 식물체 각부위내 N함량은 증가하였다. 특히 N성분은 엽부위에 다량으로 집적 되어 있어 저장양분으로서의 역할을 하지못하는 것으로 사료되었다. 2. 질소비료에 대한 P성분의 반응은 식물체부위에 따라 변화가 심하게 나타났는데 엽부위로서는 P함량이 감소한 반면, 경 및 포복경에서는 예초간격이 30일에서 10일로 단축되었을 때 한하여 증가하는 양상 을 보였다. 3. K 함량은 질소를 증랭시용할때 엽과 경부위에 특히 많이 축적되었으며 근부위에서는 질소시용이 오히려 K함량을 감소시키는 요인으로 작용하였다. 그러나 N과 K함량간에는 지상부위와 포복경에서 정의 상관관계가 인정되었다. 4. Ca 함량은 엽과 경부위에서 예초간격을 짧게 하였을때 질소시용에 따른 부의 반응을 보였다.5. Mg 함량은 질소나 예초간격에 거의 영향을 받지 않았다. 6. 가용성 탄수화물함량은 질소시용량이 증가함에 따라 비례적으로 감소하였다. 그러나 예초간격의 영향은 경부위를 제외한 각부위에서 나타나지 않았다. 7. 영양성분에 대한 예초간격의 효과는 질소만큼 크지 않았으나 질소시용과 함께 나타난 유의적 변화는 부위별로 각각 다르게 표현되었다. 즉 N함량은 예초간격을 단축하였을 때 엽 및 경부위에서만 증가되었고 Ca 함량은 30일간격으로 연장할때만 증가되는 경향이었다. 한편 K 및 Mg함량은 예초간격에 의해 영향을 받지 않거나 변동이 심한 상황으로 나타났다.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.20 no.1
• /
• pp.175-185
• /
• 2018

This study was conducted to evaluate the physiological and ecological characters of rice cultivars suitable for low fertilized condition. 5 rice cultivars(Jinmibyeo, Sobibyeo, Hwayeongbyeo, Nagdongbyeo and Junambyeo) were cultivated for selection under 3 different nitrogen application levels, and 1 cultivars were selected. The results obtained are summarized as follows ; High yielded rice cultivars under low N application level were Junambyeo, Jinheng and Sobibyeo. Also these cultivars were yielded highly under conventional level(11kg/10a). Milled rice yield under conventional level(11kg/10a) was positively correlated with them under low N levels. Milled rice yield was most affected by no. of grain/m². Rice cultivars that were high crop growth rate(CGR) before heading stage were Junambyeo, Sobibyeo and Nagdongbyeo. Grain filling rate was increased mostly until 20 days after heading, and decreased after this stage. Nitrogen use efficiency was higher under low N level(5.5kg/10a) than conventional level(11kg/10a). Especially, Junambyeo was most low in Apparent recovery of applied N(AR) under low N application level, but most high in Agronomic N use efficiency(ANUE). This characteristics of Junambyeo will to be useful for selection of variety suitable for growing under low fertilized condition.

• Clinical and Experimental Reproductive Medicine
• /
• v.39 no.2
• /
• pp.52-57
• /
• 2012

Objective: During IVF, non-transferred embryos are usually selected for cryopreservation on the basis of morphological criteria. This investigation evaluated an application for array comparative genomic hybridization (aCGH) in assessment of surplus embryos prior to cryopreservation. Methods: First-time IVF patients undergoing elective single embryo transfer and having at least one extra non-transferred embryo suitable for cryopreservation were offered enrollment in the study. Patients were randomized into two groups: Patients in group A (n=55) had embryos assessed first by morphology and then by aCGH, performed on cells obtained from trophectoderm biopsy on post-fertilization d5. Only euploid embryos were designated for cryopreservation. Patients in group B (n=48) had embryos assessed by morphology alone, with only good morphology embryos considered suitable for cryopreservation. Results: Among biopsied embryos in group A (n=425), euploidy was confirmed in 226 (53.1%). After fresh single embryo transfer, 64 (28.3%) surplus euploid embryos were cryopreserved for 51 patients (92.7%). In group B, 389 good morphology blastocysts were identified and a single top quality blastocyst was selected for fresh transfer. All group B patients (48/48) had at least one blastocyst remaining for cryopreservation. A total of 157 (40.4%) blastocysts were frozen in this group, a significantly larger proportion than was cryopreserved in group A (p=0.017, by chi-squared analysis). Conclusion: While aCGH and subsequent frozen embryo transfer are currently used to screen embryos, this is the first investigation to quantify the impact of aCGH specifically on embryo cryopreservation. Incorporation of aCGH screening significantly reduced the total number of cryopreserved blastocysts compared to when suitability for freezing was determined by morphology only. IVF patients should be counseled that the benefits of aCGH screening will likely come at the cost of sharply limiting the number of surplus embryos available for cryopreservation.

• Asian Journal of Turfgrass Science
• /
• v.25 no.2
• /
• pp.217-222
• /
• 2011

Professional turfgrass applicators have reduced or eliminated phosphorus from their fertilization programs based on the assumption that soil phosphorus levels are supplying adequate amounts of phosphorus to the turfgrass. The previous researchers found that there were no P effects for turfgrass growth especially for mature turf. No effects may result from high P level in heavy thatch layer. The research was conducted for one year to investigate the effects of phosphorus fertilization programs on turfgrass performance, and monitor soil and plant tissue nutrient levels to determine the impact of the programs on a newly seeded Kentucky bluegrass. The nitrogen treatments were 20, 30 and $40g\;m^{-2}\;yr^{-1}$. The low, medium, and high nitrogen treatments were applied over 2, 4 and 6 applications, respectively. Nitrogen was applied using a formulation containing 30% of slow and 70% of fast release nitrogen sources that are representative of typical home lawn fertilizers. The phosphorus treatments were 0, 10 and $20g\;m^{-2}\;yr^{-1}$. Phosphorus was applied according to the application schedule for the nitrogen treatments. Kentucky bluegrass was seeded in May, 2010. The thickness of thatch layer was less than 1 cm and the first treatment was applied to Kentucky bluegrass in April, 2011. The low N rate treatment had acceptable color and quality ratings without high clipping yields. The high N rate treatment consistently had the highest color and quality ratings but also had very high clipping yields in comparison to the low and medium N rate treatments. Although there are significant differences in tissue P, Overall, there was no effect of phosphorus on color, quality, or clipping weights.

• Korean Journal of Environmental Agriculture
• /
• v.21 no.2
• /
• pp.136-143
• /
• 2002

Emission of methane and nitrous oxide affected by nitrogen fertilizer materials were measured simultaneously in rice paddy fields under flooding and intermittent irrigation in 2000. Studies focused on mitigating $CH_4$ emission from rice paddy fields are summarized and the possibilities and limits applied to world's rice cultivation are discussed. The mitigation options are water management, soil amendments, organic matter management, different tillage, rotation, and cultivar selection. Altering water management, in particular promoting midseason aeration by short-term drainage, is one of the most promising strategies, although these practices may be limited to the rice paddy fields where the irrigation system is well prepared. The test site was divided into two water managements: a continuously flooded plot which was maintained flooded by constant irrigation from May to September, and an intermittently drained plot in which short-term (20days) draining practices were performed one times during the flooding period. By total emission of GHGs converted by global warming potential (GWP), flooding plots were higher 170$\sim$208% than interimittent irrigation plots. For emission of GHGs in fertilizer materials, it was high in the order of Swine slurry>Urea+Rice straw>Urea>LCU. Basing on GHGs emission of urea fertilization under flooding as baseline GWP of urea fertilization and Latex-coated urea under intermittent irrigation showed lower GHGs emission by 41.4% and 55.8 respectively. In this case fertilizer use efficiency (kg unhulled rice/ of applied N) were 18.2$\sim$20.2 and 18.7$\sim$19.0 and 9.3 and 5.8$\sim$6.6 for Swine slurry and LCU and Urea+Rice straw and Urea in the continuously flooded and intermittently drained plot.