• 농업과학연구
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• 제50권4호
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• pp.967-976
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• 2023

Biochar is emerging as a promising substance for achieving carbon neutrality and climate change mitigation. It can absorb several nutrients via ion bonding on its surface functional groups, resulting in slow dissociation of the bonds. Biochar, like organic fertilizers, contributes to sustainable nutrient management. The purpose of this study was to investigate the effects of nutrient-coated biochar amendments on leafy vegetables production and soil fertility. The nutrient-coated biochar was produced by soaking rice husk biochar in a nutrient solution containing nitrogen (N), phosphorus, and potassium for 24 hours. Nutrient-coated biochar and organic fertilizers were applied to soil at a rate of 120 kg·N·ha^-1. The growth components of the leafy vegetables showed that nutrient-coated biochar led to the highest fresh weight (FW) of both lettuce and kale (i.e., 146.67 and 93.54 g·plant^-1 FW, respectively). As a result, nutrient-coated biochar amendments led to superior yield compared to the control treatment and organic fertilization. The elemental composition of leafy vegetables revealed that soil amended with nutrient-coated biochar resulted in higher nutrient contents, which was attributed to the high nutrient contents supplied by the rice husk biochar. Soil amendment with nutrient-coated biochar positively enhanced the soil fertility compared to amendment with organic fertilizer. Therefore, nutrient-coated biochar is a promising substance for enhancing agronomic performance of leafy vegetables and improving soil fertility.

• 한국패류학회지
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• 제17권1호
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• pp.27-33
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• 2001

The Ovarian developmental phases of the reproductive cycle of Rapana venosa can be classified into five successive stages by histological study: early active stage (September to February), late active stage (December to April), ripe stage (March to July), partially spawned stage (May to August), and recovery stage (June to September). To understand the characteristics of nutrient storage and utilization in the digestive gland cells with ovarian developmental phases, we examined the digestive gland - which is the major nutrient supply organ associated with ovarian development of the female purple shell - by biochemical methods. Total protein contents in the digestive gland tissues increased in March (late active stage) and reached the maximum in May (ripe and partially spawned stages), and then their levels sharply decreased in July (partially spawned and recovery stages). Total lipid contents in the digestive gland tissues reached the maximum in January (early active stage). Thereafter, their levels rapidly decreased from May (ripe and partially spawned stages) and reached a minimum in July (partially spawned and recovery stages). The total DNA contents did not significantly change regardless of the different developmental stages of the ovary. However, it was also found from biochemical analysis that changes in total RNA content follow the same seasonal cycling to protein. These results indicate that the digestive gland is an important energy storage and supply organ in purple shells, and that the nutrient contents of the digestive gland change in response to gonadal energy needs.

• Applied Biological Chemistry
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• 제29권1호
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• pp.78-82
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• 1986

버미큐라이트 폿드 시험으로 묘삼(苗蔘)의 양액재배(養液栽培)에서 N.P.K.의 수준(水準)을 달리하여 근중 ginsenoside의 함량변화(含量變化)를 조사(調査)하였다. 이들 중 어느 하나의 결제 또는 증가는 사포닌 함량(含量)의 증가 또는 감소를 보였다. 사포닌 함량에 영향을 가장 크게 주는 것은 질소이고(15.5%에서 8.9%) P.K.의 순(順)이었다. 각 ginsenoside 함량에서도 유사(類似)한 결과를 보였다. 양분환경변화에 의한 함량변이(含量變異)의 순위(順位)는 $Rd>Rb_1>Rg_1+Rf>Rc>Rg_2{\geqq}Rb_2>Re$로 Re가 가장 둔감하며 다른 요인에 관하여도 둔감할 것으로 보였다. Diol 총량이 triol 총량보다 민감하나 이들의 비(比)는 절반의 변이계수를 보였다. 영양조건에 의한 각(各) ginsenoside의 변이(變異)는 그 함량(含量)과는 무관(無關)하였다. Ginsenoside pattern의 유사도(類似度)는 총 사포닌 함량에 차이가 큰 처리간에서 낮아졌다. 뿌리의 생육(生育)은 수도수구(水道水區)에서만 유의성있게 적었다.

• 한국산림과학회지
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• 제97권5호
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• pp.492-500
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• 2008

Since vegetation significantly influences on soil carbon and nutrient storage, vegetation change has been focused on terrestrial carbon and nutrient cycling studies. In this study we investigated soil carbon and major nutrient capitals at the abandoned fields, which had different vegetation composition: a three year abandoned field ($AGR_3$), two ten years abandoned fields ($PD_{10}$ dominant with Pinus densiflora and Fraxinus rhynchophylla and $PM_{10}$ dominant with Populus maximowiczii), and an over sixty years forest ($FOR_{60}$). which were located at Hongcheon-gun, Kangwon-do, South Korea. Both main effects for organic matter (%) were significant: shallow soil > deep soil and $FOR_{60}=PM_{10}$ > $AGR_3=PD_{10}$. Nitrogen concentrations at $PM_{10}$ were the highest, while the lowest at $PD_{10}$. Available phosphorus concentrations were the highest at $PD_{10}$, which were over 10 times of site $FOR_{60}$ and $AGR_3$ at 0-10 cm soil depth. The average organic matter ($173Mg\;ha^{-1}$) and nitrogen contents ($10Mg\;ha^{-1}$) of $PM_{10}$ and $FOR_{60}$ were higher than those of $AGR_3$ and $PD_{10}$ by 57% and 42%, respectively. The available phosphorus contents above 30 cm mineral soil at $PD_{10}$ ($3.8Mg\;ha^{-1}$) and $PM_{10}$ ($1.3Mg\;ha^{-1}$) were over 120 times and 40 times more than at $FOR_{60}$. Calcium ($3.7Mg\;ha^{-1}$) and magnesium contents ($2.8Mg\;ha^{-1}$) at $FOR_{60}$ were twice or three times higher than at other sites. Organic matter amounts in 0-10 cm and 10-30 em soil had significant positive relationships with nitrogen, calcium, and magnesium contents, but not available phosphorus and potassium contents. This study could not identify the effect of chronological factor and vegetation composition on soil carbon and nutrient capital owing to diverse topography as well as limited study sites. However, this study suggests the accuracy of investigation for regional carbon and nutrient sequestration can be achieved by considering the period of abandoned time on the fields and the land use types. These results may suggest the benefits of forest restoration for soil carbon and nutrient accumulation in marginal agricultural lands in South Korea.

• Journal of Forest and Environmental Science
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• 제37권3호
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• pp.193-205
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• 2021

The importance of forests and trees in climate change mitigation and soil nutrient cycling cannot be overemphasized. This study assessed the above-ground carbon stock of two exotic and two indigenous tree species - Gmelina arborea, Tectona grandis, Khaya grandifoliola and Nauclea diderrichii and their litter impact on soil nutrient content of an arboretum within the University of Port Harcourt, Nigeria. Data were collected from equal sample plots from the four species' compartments. Tree growth variables including total height, diameter at breast height, crown height, crown diameter and merchantable height were measured for the estimation of above-ground carbon stock. Soil samples were collected from a depth of 0-30 cm from each compartment and analyzed for particle size distribution, organic carbon, total nitrogen, available phosphorus, exchangeable bases, exchangeable acidity, cation exchange capacity, base saturation, pH, Manganese, Iron, Copper and Zinc. Analysis of Variance (ANOVA) was used to test for significant difference (p<0.05) in the carbon contents of the four species and the soil nutrient contents of the different species' compartments. Pearson correlation was used to assess the relationships between the carbon contents, growth parameters and soil parameters. The highest and lowest carbon stock per hectare was observed for G. arborea (151.52 t.ha^-1) and K. grandifoliola (45.45 t.ha^-1) respectively. Cation exchange capacity and base saturation were highest and lowest for soil under G. arborea and K. grandifoliola respectively. The pH was highest and lowest for soil under G. arborea and T. grandis respectively. Carbon stock correlated positively with dbh, crown diameter, merchantable height and Zn and negatively with base saturation. The study revealed that G. arborea and N. diderrichii can effectively be used for reforestation and afforestation programmes aimed at climate change mitigation across Nigeria. Therefore, policies to encourage and enhance their planting should be encouraged.

• 한국대기환경학회지
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• 제12권3호
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• pp.263-268
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• 1996

This study was conducted for the assessment of the effects of acid rain and soil fertilizers on photosynthetic rate, was content, and contact angle on 5-year seedlings of Japanese red pine (Pinus densiflora Sieb. et Zucc.) leaves. The seedlings were exposed to pH 3.0 (simulated acid rain), pH 6.5 (groung water) and rain (pH around 4.6). The seedlings were also treated with $Ca(OH)_2, Mg(OH)_2, and Ca(OH)_2 + Mg(OH)_2 + C.F.(compound fertilizer)$. Photosynthetic rate, stomatal conductance, was content, contact angle value, and mineral nutrient content of the leaves were measured and the results were as follows: 1. Photosynthetic rate and stomatal conductance of the leaves increased with the increase of pH. Photosynthetic rate and stomatal conductance increased with application of soil fertilizer in the pH 3.0 treatment, but showed no changes in the rain and the pH 6.5. 2. Contact angle value and was content of the leaves did not change with the pH treatment, but increased with the fertilizer treatments. 3. Mineral nutrient contents of the leaves were lowest in the rain treatment and highest in the pH 6.5 treatment. The increase of mineral nutrient contents was observed with the soil fertilizer treatments.

• 한국토양비료학회지
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• 제36권4호
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• pp.225-232
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• 2003

노지에서 분무식 양액재배를 이용하여 감귤나무(Citrus unshiu Marc. cv. Miyagawa Wase)의 무기양분과 물 흡수 실험을 수행하였다. 양액의 농도는 세 수준으로 나누어 공급한 뒤 주기적으로 양액을 채취하여 무기양분과 물 흡수량을 측정하였고, 생체중의 변화를 조사하여 수체 증가량을 알아보았다. 물의 흡수는 감귤나무의 수체와 시간이 경과할수록 증가하였으나, High 처리구에서는 Medium과 Low보다 적게 흡수되었다. 영양생장(5~7월)과 과실형성(8~9월)기에 생체중과 양분흡수 증가가 가장 크게 일어났다. 양분의 흡수는 양액 공급 농도에 따라 차이가 컸으며, 높을수록 더 많이 흡수하는 경향이었고, $NH_4-N$, S, P, Mg, Fe보다 $NO_3-N$, K, Ca가 많았다. 또한 감귤잎 중 무기양분 함량도 공급되는 양액의 농도가 높을수록 증가하였다. 감귤나무의 주요 원소의 양액 농도 조성은 N, P, K, Ca, Mg 경우 각각 27.1, 16.5, 66.0, 80.0, $24.0mg\;L^{-1}$이 적당힌 것으로 사료된다.

• 생물환경조절학회지
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• 제6권4호
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• pp.299-309
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• 1997

본 실험은 수경재배에서 딜의 양수분 흡수 패턴을 밝히고 생육과 환경특성에 적합한 배양액을 개발하여 실제 재배에 응용하고자 수행하였다. 이를 위해 딜의 양분 홉수율에 의한 배양액을 조성하였으며 그 적합성을 검정하기 위해 기존배양액과 비교실험을 실시하였다. 딜의 NFT재배에 적합한 배양액을 개발하기 위해서 일본야채시험장 표준액을 1/4배액, 1/2배액 및 1배액으로 조성하여 재배한 결과, 1/2배액에서 생육과 수량이 가장 높았으며 근권내 pH와 EC의 변화도 안정되었고, 식물체내 무기이온 합량도 적정치로 나타나 딜의 양분흡수특성에 적합할 것으로 판단되었다. 따라서 일본야채시험장 1/2 배액의 양수분 흡수율(n/w)을 기준으로 새로운 배양액을 조성하였으며, 이온의 조성은 NO$_3$―N 8.85, NH$_4$―N 0.55, P 2.1, K 6.2, Ca 2.8, Mg 1.7 me.L$^{-1}$였다. 딜의 순환식 NFT 재배용으로 개발한 배양액의 적합성 검정실험 결과, 근권내 pH와 EC는 저농도인 SCU 1/2배액을 제외하고는 변화폭이 크게 나타나지 않았다. 본 실험에서 개발된 SCU 1배액은 기존에 허브 배양액으로 사용된 일본 야채 시험장 배양액과 비교할 때 생육과 수량면에서 우수하였으며, 엽내 무기성분 함량도 적정수준을 나타내었다. 따라서, 본 실험에서 개발된 SCU 배양액은 딜의 NFT재배에 적합한 배양액이라 할 수 있다.

• Journal of Ecology and Environment
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• 제29권5호
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• pp.469-478
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• 2006

The composition changes of litters were investigated to figure out the effects of the decomposition of Humulus japonicus on nutrient circulation and decomposition process in the riverine wetlands: Tan stream and Amsa-dong. Litterbags (mesh size 1 mm and 5 mm) were installed to monitor mass and nutrient changes of 5 types of litters: H. japanicus only, Miscanthus sacchariflarus only, Phragmites communis only, mixed litters including H. japonicus, and mixed litters without H. japonicus for 7 months. It was shown that k (decay rate) of the H. japanicus ($2.68{\sim}3.12$) was higher than that of M. sacchariflorus ($1.83{\sim}2.16$) and P. communis ($0.02{\sim}1.18$). The mass and organic remainings of the mixed litters including H. japonicus at Tan stream were $47.0{\sim}55.1%\;and\;47.0{\sim}54.9%$ and those of the litterbags without H. japanicus were $49.2{\sim}65.4%\;and\;47.1{\sim}57.5%$, respectively. This result indicated that the nutrient circulation was faster at H. japanicus community than others. Ca, Na, Mg, K, P, C, N and H contents reduced to around $40{\sim}80%$ of original. However, Na concentration increased up to $407{\sim}584%$ at 100 days and decreased to $248{\sim}498%$ at the end of the experiment. Decomposition rates were similar between 1 mm and 5mm mesh size litterbags and this implies that plant litters in studied areas decomposed mainly by microbes rather than small animals. This study revealed that the fast growth of H. japonicus was resulted from fast decomposition in part: positive feedback of nutrient cycling.

• 한국환경농학회지
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• 제28권1호
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• pp.32-37
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• 2009

본 연구는 산촌형 조건불리 지역의 농업 소수계에서 영농활동이 주변 수질환경에 미치는 영향을 평가하고자 하였다. 고성천 유역에서 토지이용형태별 토양의 화학적 특성을 비교한 결과, 논토양과 밭토양의 pH와 유기물의 함량은 비슷하였으나, 밭토양은 논토양에 비해 유효인산과 치환성 칼리와 칼슘의 함량이 월등히 높았다. 또한, 고성천의 수질 모니터링 결과, 하부로 내려갈수록 영양물질의 농도는 높았으며, 특히 전 조사지점에서 평상시에 비해 강우시에 $COD_{Mn}$과 T-P의 농도가 높았다. 유역내 논과 밭이 혼재되어 있는 지류에서 토지이용형태별 SS 및 T-N과 T-P의 농도 부하 특성을 평가한 결과, 논은 다른 토지이용형태에 비해 영양물질을 흡수하는 특성을 가지고 있어 영양물질의 지표배출 감소 효과 및 유입된 영양물질의 저류 능력을 지니고 있어 수질정화 효과가 있었다. 산촌형 조건불리 지역인 고성천 유역에서 영농기간 동안 질소와 인의 유입량-유출량은 -98.9와 -29.7 kg $ha^{-1}$로 유출되는 양이 많았는데, 이는 고성천 유역이 전형적인 농업지역으로 영농활동으로 인한 투입량이 적은 반면에 수확물로의 배출량이 많았기 때문으로 생각된다.