• 한국지하수토양환경학회지:지하수토양환경
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• 제26권6호
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• pp.157-164
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• 2021

Smart agriculture requires sensing systems which are fundamental for precision agriculture. Adequate and appropriate water and nutrient supply not only improves crop productivity but also benefit to environment. However, there is no available soil sensor to continuously monitor nutrient status in soil. Electrical conductivity (EC) of soil is affected by ion contents in soil and can be used to evaluate nutrient contents in soil. Comparison of various commercial EC sensors showed similar water content and EC values at water content less than 20%. Soil EC values measured by sensors decreased with decreasing soil water content and linearly correlated with soil water content. EC values measured by soil sensor were highly correlated with water soluble nutrient contents such as Ca, K, Mg and N in soil indicating that the soil EC sensor can be used for monitoring changes in plant available nutrients in soil.

• 한국토양비료학회지
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• 제46권6호
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• pp.487-493
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• 2013

The effects of long-term fertilization on soil biological properties and microbial community structure in the plough layer in a rice paddy soil in southern Korea were investigated in relation to the continuous application of chemical fertilizers (NPK), straw based compost (Compost), combination these two (NPK + Compost) for last 40 years. No fertilization plot (Control) was installed for comparison. Though fertilization significantly improved rice productivity over control, the long-term fertilization of NPK and compost combination was more effective on increasing rice productivity and soil nutrient status than single application of compost or chemical fertilizer. All fertilization treatments had shown significant improvement in soil microbial properties, however, continuous compost fertilization markedly increased soil enzyme and microbial activities as compared to sole chemical fertilization. Results of microbial community structure, evaluated by EL-FAME (ester-linked fatty acid methyl esters) method, revealed big difference among Control, NPK, and Compost. However, both Compost and Compost+NPK treatments belonged to the same cluster after statistical analysis. The combined application of chemical fertilizer and organic amendments could be more rational strategy to improve soil nutrient status and promote soil microbial communities than the single chemical fertilizer or compost application.

• The Korean Journal of Ecology
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• 제16권1호
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• pp.115-131
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• 1993

Six nutrient cycles involving terrestrial plants are identified and characterized. Plants affect biotic and abiotic cycles through their effects on soil properties. They determine their internal nutritional status and nutrient concentrations in their environment via internal and external cycles. Contributions of organic matter to mycorrhizal, trophic, and detrital mediated external cycles and alterations of nutrient concentrations by plants can promote positive feedbacks leading to increased availability and retention of soil nutrients in open systems. Recognizing alternative cycles through plants leads to a definition of nutrient use efficiency for ecosystems: the ratio of system production to nutrient content of organic matter. A simple graph model to predict changes of nutrient use efficiency during primary succession is then presented.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권1호
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• pp.1-15
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• 2004

Due to recent scientific innovations in mulberry cultivation, leaf yield has been increased manifold. However, with successive leaf harvest, a quantum drop in leaf yield and quality has been noted. This inturn has affected the silkworm rearing and farmers suffered by the frequent crop failures. This is mainly due to nutrient deficiencies in mulberry leaf. Moreover, no complete information is available about hunger signs of nutritional disorders, analytical diagnosis and critical levels of nutrients required. The present paper, thus, may serve as an important nutrient guide for identification of hunger signs, leaf nutrients status under deficiency and critical levels of the elements namely N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn requirements for higher leaf yield and quality. The leaf nutrient status provided may help chemist for correcting the soil status. Besides, an integration of mulberry intercropping with legumes and applications of neem and castor oil cakes, VA-mycorrhizal inoculation, biofertilizer and vermicompost are suggested as integrated nutrient management for sustainable sericulture industry. Based on the information described in this paper, a model needs to be framed for maintaining continuous supply of nutrients to obtain desired quantity and quality of mulberry leaf for successful silkworm cocoon crop and increasing overall silk productivity.

• 한국토양비료학회지
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• 제16권2호
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• pp.98-105
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• 1983

토양수분조건에 따른 시비반응을 구명(究明)하기 위하여 본량(本良) 사양토(砂壤土)에서 토양수분처리($M_0$무관수, $M_1$-0.1~-1.0bar, $M_2$-0.1bar~-0.5bar, $M_3$-0.1~-0.2bar)와 시비수준(施肥水準)(N-P-Kkg/10a, 0-0-0, 11.5-10-12.5, 23-20-25, 34.5-30-37.5)을 달리하여 봄배추의 생육상태(生育狀態), 물소모량(消耗量), 양분흡수량, 비료이용율(肥料利用率), 수량 등을 조사(調査)한 결과(結果)는 다음과 같다. 1) 20cm 깊이에서 토양수분 Potential이 -2.0bar 이하(以下)일 때 물소모량은 감소(減少)하였고 비료(肥料)에 의(依)한 생장량(生長量)의 증가는 없었다. 2) 배추의 양분흡수량(養分吸收量)은 시비량(施肥量)의 증가에 따라 토양수분 Potential이 낮을 때는 감소(減少)하는 경향(傾向)이었고, 토양수분 Potential이 높을 때는 증가하는 경향(傾向)이었다. 3) 질소(窒素)와 가리(加里)의 이용율(利用率)은 토양수분 Potential과 시비수준(施肥水準)이 정비례관계(正比例關係)에 있어야 이용율(利用率)이 증대되었다. 4) 봄배추의 수량(收量)은 토양수분 Potential이 낮을 때에는 시비량(施肥量)을 증가시켜도 증수가 없었으며, 토양수분 Potential이 높을 때에는 각(各) 시비수준(施肥水準) 공(共)히 증수효과(增收效果)가 있었고 그 효과(效果)는 다비수준(多肥水準)에서 더욱 뚜렷하였다. 5) 토양수분 Potential을 높게 유지(維持)시킬 경우(境遇)에는, 시비량(施肥量)을 증가시킴에 따라 봄배추 수량(收量)이 거의 직선적(直線的)인 증가경향을 보여, 최대수량을 낼 수 있는 비료요구량(肥料要求量)이 크게 증가되었다.

• Journal of Microbiology and Biotechnology
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• 제21권11호
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• pp.1127-1142
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• 2011

The aim of this investigation was to select effective Pseudomonas sp. strains that can enhance the productivity of soybean-wheat cropping systems in Vertisols of Central India. Out of 13 strains of Pseudomonas species tested in vitro, only five strains displayed plant growth-promoting (PGP) properties. All the strains significantly increased soil enzyme activities, except acid phosphatase, total system productivity, and nutrient uptake in field evaluation; soil nutrient status was not significantly influenced. Available data indicated that six strains were better than the others. Principal component analysis (PCA) coupled cluster analysis of yield and nutrient data separated these strains into five distinct clusters with only two effective strains, GRP3 and HHRE81 in cluster IV. In spite of single cluster formation by strains GRP3 and HHRE81, they were diverse owing to greater intracluster distance (4.42) between each other. These results suggest that the GRP3 and HHRE81 strains may be used to increase the productivity efficiency of soybean-wheat cropping systems in Vertisols of Central India. Moreover, the PCA coupled cluster analysis tool may help in the selection of other such strains.

• 한국산림과학회지
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• 제111권1호
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• pp.108-114
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• 2022

In bamboo, the nutrient status of tissues and associated soil is an important indicator of nutrient uptake by various bamboo species. In this study, the nutrient concentrations of leaves, roots, and mineral soil at 0-10 cm depths were examined in three bamboo stands [Phyllostachys bambusoides S ieb. et Zucc, Phyllostachys nigra var. henonis Stapf ex. Rendle, and Phyllostachys pubescens (Mazel) Ohwi] at a broad regional scale in southern Korea. In the three bamboo species, species-specific differences were observed in the carbon (C) and calcium (Ca) concentrations of leaves and in the nitrogen (N) and magnesium (Mg) concentrations of roots. Ca concentrations in leaves were significantly higher in P. bambusoides (11.94 g Ca kg^-1) than in P. pubescens (7.83 g Ca kg^-1), whereas potassium (K) concentrations were lowest in P. bambusoides among the three bamboo species. N concentrations in the roots were significantly lower in P. pubescens (5.23 g N kg^-1) than in P. nigra var. henonis (7.72 g N kg^-1). In contrast to bamboo tissues, soil nutrients, such as total N, organic C, exchangeable Ca²⁺, and Mg²⁺, did not differ significantly among the bamboo species. These results suggest that species-specific practices will be required for nutrient management of bamboo stands because nutrient concentrations vary considerably in the tissues of the three studied species.

• 한국토양비료학회지
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• 제50권2호
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• pp.93-99
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• 2017

Analysis of mineral nutrients in plant is required for evaluating diagnosis of plant nutritional status. Pretreatment procedure for the analysis of plant can be varied depending on elements to be analyzed. Wet-digestion is suitable for total nitrogen, phosphate and cations, however, digestion solution including nitric acid is not suitable for nitrogen analysis. Incineration procedure is required to analyze chloride, silicate and total sulfur. After digestion, total nitrogen is analyzed by Kjeldahl method, and phosphate is detected at 470nm by colorimetric analysis with ammonium meta vanadate. Cations and micro elements are determined by titration or colorimetry, also, these elements can be measured by Atomic absorption spectrometer (AAS) or Inductively coupled plasma spectrometer (ICP).

• 한국산림과학회지
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• 제87권4호
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• pp.611-619
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• 1998

황산용액을 첨가하여 인위적으로 산성화시킨 갈색산림토양에 2년생 소나무 묘목을 온실내에서 120일 동안 생육시킨 후, 묘목의 생장과 영양상태를 조사하였다. 토양용액의 Al 농도는 토양의 $H^+$ 부하량이 증가함에 따라 증가하였으며, 또한 소나무 묘목의 건물생장은 토양의 $H^+$ 부하량이 증가함에 따라 감소하였다. 소나무 묘목 지하부 Al 농도의 증가는 엽내 Ca 및 Mg 등과 같은 식물생장 필수원소 농도의 저하를 초래하였다. 소나무 묘목의 건물생장과 토양용액의 (Ca+Mg+K)/Al 몰비와의 사이에 높은 상관이 있는 것으로 나타났으며(r=0.96, p<0.001), 토양용액의 (Ca+Mg+K)/Al 몰비가 7.0이하로 낮아지면 건물생장이 감소가 발생하고 몰비가 1.0일 때의 건물생장은 대조구에 비하여 약 40% 감소하였다. 이상의 결과를 종합할 때 토양용액의 (Ca+Mg+K)/Al 몰비의 이용은 산성강하물에 대한 임계부하량 평가에 중요한 지표(指標)가 될 수 있다고 생각된다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1194-1196
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• 2003

Variations in soil physical and chemical properties can affect agricultural productivity and the environmental implications of crop production. These variations are present and may be important at regional, field, and sub-field (precision agriculture) scales. Because traditional measurements are time-consuming and expensive, reflectance-based estimates of soil properties such as texture, organic matter content, water content, and nutrient status are attractive. Soil properties have been related to reflectance measured with laboratory, in-field, airborne, and satellite sensors. Both multispectral and hyperspectral instruments have been used, with both natural and artificial illumination. Varying levels of accuracy have been obtained, with the best results (r > 0.95) using hyperspectral reflectance data to estimate soil organic matter and water content.