• 한국토양비료학회지
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• 제31권4호
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• pp.350-358
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• 1998

시설재배 토양의 염류집적 방지를 위한 적정 시비량 추천방안을 구명하기 위하여 1997년도에 영동군, 보은군, 청원군, 및 청주시의 시설재배지로부터 염류농도가 다양한 18개 토양을 채취하여 폿트 시험으로 무비구와 시비구로 구분하여 토마토의 생산성과 비료효과를 조사하였다. 무비구의 토마토 건물중 및 질소, 인산, 칼륨 흡수량을 비옥도 요인으로 그리고 이들의 시비구와 무비구의 차이 값을 비료 전체효과 및 비료 질소, 인산, 칼륨효과로 고려하였다. 비옥도 및 비료효과 요인들은 토양 화학성들의 상호관계를 분석하여 시설재배지 토마토의 시비기준을 설정하기 위한 평가방법을 검토하였다. 비옥도 요인들에 대한 무기태 질소($NO_3-N$, $NH_4-N$) 함량의 표준화 편회귀계수는 247~1159의 범위를 보여 다른 화학성들의 0.02~4.02에 비하여 수백배의 높은 가중치를 보였다. 또한 무기태 질소($NO_3-N$, $NH_4-N$) 함량은 전기전도도에 대한 표준화 편회귀계수가 35.2-36.0으로 다른 화학성들의 1.0이하에 비하여 수십배의 높은 가중치를 나타냈다. 이러한 결과로부터 무기태 질소함량은 시설재배 토양의 비옥도와 전도도에 가장 크게 영향을 미치는 지표로 확인되었다. Cate-Nelson split 평가방법에 의한 토마토 최대 생산력과 비료효과 0가 되는 무기태 질소($NO_3-N+NH_4-N$) 함량은 $220mg\;kg^{-1}$으로 배추의 경우와 동일하게 추정되었다. 따라서 시설재배지 토양의 무기태 질소($NO_3-N$, $NH_4-N$) 함량이 $220mg\;kg^{-1}$ 이상인 토양은 무비 재배로 추천하고, 기준치 이하인 토양은 비료효과와 무기태질소 함량의 회귀식을 이용하여 시비기준의 추천이 가능하다.

• Applied Biological Chemistry
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• 제46권2호
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• pp.140-143
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• 2003

본 연구는 지금까지 제시된 여러 가지 간이 식물영양 진단 방법들 중 test strip과 chlorophyll meter의 이용가능성을 검토하고 실제 이용 방안을 모색하고자 수행되었다. 본 실험에서는 양액의 N, P, K수준을 달리하여 토마토를 재배하면서 생육시기별로 specific color difference sensor value (SCDSV), 엽병 즙액 중 $NO_3,\;PO_4,\;K$의 함량을 측정하였다. 실험 결과 양액중 N, P, K의 농도 변화에 따른 엽병 즙액 중 $NO_3,\;PO_4,\;K$ 함량 변화가 엽 중 total-N, E, K함량의 변화보다 더 민감하였다. Test strip을 이용하여 측정한 토마토 엽병 즙액 중 $NO_3,\;PO_4,\;K$ 함량은 엽 내 total-N, E, K의 농도와 고도의 일차상관관계를 나타내었다. 지금까지 여러 연구를 통해 확립된 토마토의 엽 중 total-N, E, K의 적정 함량을 희귀식에 대입하여 구한 즙액의 적정 $NO_3,\;PO_4,\;K$의 함량은 각각 3.4-5.9, 0.3-0.5, 3.6-6.5 g/l였다.. Chlorophyll meter를 이용하여 측정한 SCDSV는 엽 중 total-N와 높은 상관관계를 나타내었으며 기존에 연구된 토마토의 엽 중 total-N 함량을 희귀식에 대입하여 계산한 결과 적정 SCDSV는 36.0-40.0이었다. 본 연구 결과 test strip과 chlorophyll meter는 토마토의 신속한 영양 진단에 이용할 수 있을 것으로 판단된다.

• 한국토양비료학회지
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• 제36권5호
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• pp.272-279
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• 2003

본 연구는 지금까지 제시된 여러 가지 간이 영양 진단 방법들 중 test strip과 chlorophyll meter를 이용하여 오이의 영양상태를 신속하게 파악하기 위한 방안을 모색하고자 시행하였다. 본 실험에서는 양액에 공급하는 N, P, K 수준을 달리하여 오이를 재배하면서 생육시기별로 specific color difference sensor value (SCDSV), 엽병의 즙액 내 $NO_3$, $PO_4$, K의 함량을 측정하였다. 실험 결과 양액 중 N, P, K의 농도변화에 따른 엽병 중 $NO_3$, $PO_4$, K 함량 변화가 엽 내 total-N, P, K 함량의 변화보다 더 민감하였다. Test strip을 이용하여 구한 오이 엽병 즙액 내 $NO_3$, $PO_4$, K 함량은 엽 내 total-N, P, K의 농도와 고도의 일차상관관계를 나타내었다. 따라서 지금까지 여러 연구를 통해 확립된 오이의 엽 내 total-N, P, K의 적정함량을 회귀식에 대입하여 즙액 $NO_3$, $PO_4$, K의 적정함량을 계산하였다. 오이 즙액의 적정 $NO_3$, $PO_4$, K 범위는 각각 5.4-9.1, 0.2-0.5, $3.1-4.8g\;L^{-1}$였다. Chlorophyll meter를 이용하여 측정한 SCDSV는 엽 내 total-N와 높은 상관관계를 나타내었으며 기존에 연구된 오이의 엽 내 total-N 함량을 회귀식에 대입하여 계산한 결과 적정 SCDSV는 39.5-49.0이었다. 본 연구 결과 test strip과 chlorophyll meter는 오이의 신속한 영양 진단에 이용할 수 있을 것으로 판단된다.

• Clinical and Experimental Reproductive Medicine
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• 제42권2호
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• pp.67-71
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• 2015

Objective: Elevated serum progesterone (P) levels on triggering day have been known to affect the pregnancy rate of in vitro fertilization (IVF). This study aimed to identify the possible factors influencing serum P levels on triggering day in stimulated IVF cycles. Methods: Three hundred and thirty consecutive fresh IVF cycles were included in the study. All cycles were first attempts and were performed in a single infertility center. The indications for IVF were male factor infertility (n=114), ovulatory infertility (n=84), endometriosis (n=61), tubal infertility (n=59), unexplained infertility (n=41), and uterine factor infertility (n=39). A luteal long protocol of a gonadotropin-releasing hormone (GnRH) agonist (n=184) or a GnRH antagonist protocol (n=146) was used for pituitary suppression. Ovarian sensitivity was defined as the serum estradiol level on triggering day per 500 IU of administered gonadotropins (OS[a]) or the retrieved oocyte number per 500 IU of administered gonadotropins (OS[b]). Results: Univariate analysis revealed that the serum P level on triggering day was associated with the serum estradiol level on triggering day (r=0.379, p<0.001), the number of follicles ${\geq}14mm$ (r=0.247, p<0.001), the number of retrieved oocytes (r=0.384, p<0.001), and ovarian sensitivity (OS[a]: r=0.245, p<0.001; OS[b]: r=0.170, p=0.002). The woman's age, body mass index, antral follicle count, and basal serum follicle stimulating hormone and estradiol levels were not associated with serum P level on triggering day. The serum P level on triggering day did not show significant variation depending on the type or cause of infertility, pituitary suppression protocol, or the type of gonadotropins used. Conclusion: The serum P level on triggering day was closely related to the response to ovarian stimulation.

• 한국초지조사료학회지
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• 제9권2호
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• pp.68-76
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• 1989

The effect of characteristic of mixture sowing combination on the development of botanical composition was conducted for 12 years on the meadow experiment. The results of this study were summarized as follows. 1. Festuca pratensis lost the expected position of a dominant species. Its vegetation ratio decreased gradually until the last survey year. 2. Arrhenatherum elatius, known as a typical 2-cutting grasss, developed to a dominant species only in the 3- cutting plot without limitation. 3. Alopecurus pratensis, whose feeding value diminishes rapidly, developed to a dominant species regardless of N-fertilization under the condition of 3-cutting, even though the same small amount of seeding was introduced as usual. 4. Trisetum flavescens which causes calcinose exceeded the 40% of vegetation ratio which was the approved rate for feeding at the high N-level (2OOKgIha). 5. Among the introduced, the species showed the significance in quantity were Lotus corniculafus solely in the 2-cutting plot, and Trifolium repens solely in the 3-cutting plot. In the 3-cutting plot legume yet remained under N-fertilization. 6. The appropriate ratio of vegetation for the subordinate species in the mixture sowing combination was easily attained from the least amount of seeding (Gramineae with max. 3Kg/ha, Leguminosae with max. 2kgIha). 7. Into the mixture sowing combination, infiltrated unintroduced species marked more noticeably in the 2- cutting plot than in the 3-cutting plot.

• 한국토양비료학회지
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• 제48권3호
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• pp.205-212
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• 2015

Farmers with forage barley (Hordeum vulgare L.)-rice (Oryza sativa L.) cropping system at reclaimed tidal lands burn crop residues to facilitate seedbed preparation or remove them for feed stock. This study was conducted to investigate the effect of rice straw amendment and N fertilization on soil properties and N uptake of rice under forage barely-rice cropping system at reclaimed tidal paddy field. Rice straw was applied at the rates of 0, 2.5 and $5.0ton\;ha^{-1}$ and N was fertilized at 0, 100, 200 and $400kg\;ha^{-1}$. Although there was no significant difference in the growth and yield of rice, fresh and dry weight of forage barely increased with increasing the amount of rice straw. The amount of N uptake of rice at harvesting stage was $65.8-69.2kg\;ha^{-1}$ by the amount of rice straw amendment, but there were no significant differences among rice straw amendment levels. After harvesting the rice, the soil salinity decreased with rice straw amendment compared to the control. After forage barely and rice cultivation, soil organic matter contents increased to $2.6-2.8g\;kg^{-1}$ and $3.2-3.5g\;kg^{-1}$, respectively. The amount of N uptake of rice at harvesting stage increased up to $82kg\;ha^{-1}$ in $400kg\;ha^{-1}$ N applied plots which were $37.8kg\;ha^{-1}$ higher than the control. Nitrogen fertilization decreased N recovery efficiency. The highest yield of rice was observed at $244kg\;ha^{-1}$ N fertilization level, but the optimum N level was estimated at $168kg\;ha^{-1}$ in order to keep the protein content of rice under 6.5%. Further researches on N uptake and application of organic matter according to soil salinity will be necessary to increase N use efficiency at reclaimed tidal paddy field.

• 한국환경농학회지
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• 제42권1호
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• pp.28-34
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• 2023

Nitrogen fertilizers applied to agricultural lands for crop cultivation can be volatilized as ammonia. The released ammonia can catalyze the formation of ultrafine dust (particulate matter, PM2.5), classified as a short-lived climate change pollutant, in the atmosphere. Currently, one of the prominent methods for fertilizer application in agricultural lands is soil surface application, which comprises spraying the fertilizers onto the soil surface, followed by mixing the fertilizers with the soil. Owing to the low nitrogen absorption rate of crops, when nitrogen fertilizers are applied in this manner, they can be lost from land surfaces through volatilization. Therefore, investigating a new fertilization method to reduce ammonia emissions and increase the fertilizer utilization efficiency of crops is necessary. In this study, to develop a method for reducing ammonia emissions from nitrogen fertilizers applied to soil surfaces, deep fertilization was conducted using a newly developed deep fertilization device, and ammonia emissions from barley, garlic, and onion fields were examined. Conventional fertilization (surface application) and deep fertilization (soil depth of 25 cm) were conducted for analysis. The fertilization rate was 100% of the standard fertilization rate used for barley, and deep fertilization of N, P, and K fertilizers was implemented. Ammonia emissions were collected using a wind tunnel chamber, and quantified subsequently susing the indole-phenol blue method. Ammonia emissions released from the basal fertilizer application persisted for approximately 58 d, beginning from approximately 3 d after fertilization in conventional treatments; however, ammonia was not released from deep fertilization. Moreover, barley, garlic, and onion yields were higher in the deep fertilization treatment than in the conventional fertilization treatment. In conclusion, a new fertilization method was identified as an alternative to the current approach of spraying fertilizers on the soil surface. This new method, which involves injecting nitrogen fertilizers at a soil depth of 25 cm, has the potential to reduce ammonia emissions and increase the yields of barley, garlic, and onion.

• 한국초지조사료학회지
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• 제18권2호
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• pp.113-122
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• 1998

This experiment was conducted to establish the cultural method of triticale(Triticum Secalotriticum Saratoviense Meister) as a whole crop silage by evaluating the effect of seeding date and nitrogen fertilization rate on forage yields and feeding value. Heading date, flowering date, and the dough stage of development came significantly earlier as triticale was seeded earlier. Soilage, dry matter yields and percent dry matter significantly varied with seeding dates and crude ash, NFE and TDN. However, TDN yield was significantly reduced by delayed seeding. Macromineral contents were not affected by seeding date. Soilage, dry matter yield, and percent dry matter significantly increased as nitrogen fertilization rate increased. The contents of crude protein, crude fat, crude ash, NFE, TDN and TDN yield also significantly increased. In contrast, crude fiber content of triticale decreased with increasing N fertilization rate.

• 한국초지조사료학회지
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• 제11권1호
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• pp.17-21
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• 1991

A field experiment was carried out to determine the effects of nitrogen(N) fertilization levels(0, 30, 60, 90 and 120 kg/ha) in early spring on the growth, dry matter(DM) yield, seasonal distribution of production and nutritive value of grasses. Additional N after the first, second and third harvest were applied as 60, 60 and 30 kg/ha, equally in 1989. Grass growth and DM yield were significantly increased(p$NO_3$-N concentration was not affected by N level of early spring. It is suggested that, therefore, N application in early spring is essential, and 60 to 90 kg/ha of N application may be desirable in early spring.

• Weed & Turfgrass Science
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• 제4권4호
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• pp.383-389
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• 2015

The use of zoysiagrass (Zoysia japonica Steud.) in the transition zone is limited because of a lack of cold hardiness although zoysiagrass has many advantages compared to other warm-season and cool-season grasses. Late-fall N fertilization is often applied for darker green color of turfgrass in early spring and more extensive root growth without rapid top growth. The objective of the study was to evaluate the effects of late fall N application and turf cover for zoysiagrass spring green-up. Clear polyvinyl chloride (PVC) film was used for turf cover. The amount of N applied were 5 and $10g\;N\;m^{-2}$ for the low and high N rate treatments, respectively. Covered zoysiagrass had greater turfgrass color and quality in early spring than non-covered zoysiagrass. The high N rate had 0.6 to 2.3 greater turfgrass quality than the low N rate on 7 of 9 rating dates. Slow-release N as late fall fertilization is more effective for turfgrass color and quality than fast-release N in spring. Turf cover could reduce the period of yellow zoysiagrass, and the earlier time of spring green-up could be advanced by increasing turfgrass quality and growth of zoysiagrass.