• 한국토양비료학회지
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• 제45권1호
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• pp.98-102
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• 2012

Organic farming has rapidly increased in Gangwon province, but there is a concern about nutrient accumulation and nutrient imbalance in the soil of organic farming. This study was conducted to investigate the impact of continuous application of organic amendments on growth and yield of red pepper and soil characteristics compared with chemical fertilizers application for four years. Treatments of organic amendments including oil cake, rice straw compost, amino acid compost, rice bran compost, and mushroom media (spent substrate) compost resulted in comparable growth and yield of pepper to chemical fertilizers. Organic amendments improved soil physical and chemical characteristics. Especially, rice bran compost and oil cake significantly increased soil organic matter compared with chemical fertilizer application and mushroom media compost and rice straw compost significantly improved soil aggregate stability. On the other hand, available phosphate level in the soil amended with rice bran compost or mushroom media compost was relatively high compared with the other treatments due to relatively high phosphate levels in the composts. It is not easy to adjust nutrient composition in the organic materials. Therefore, the results obtained from the study imply that nutrient imbalance needs to be carefully considered in organic farming without use of chemical fertilizers.

• 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.

• 한국유기농업학회지
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• 제15권4호
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• pp.399-411
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• 2007

Korean organic farming has been well developed over the last two decades. It demonstrates that the number of certificated farm for organic agriculture and products have been drastically increased in recent year. However, the organic farmers have thought that organic farming rely only on organic fertilizer and they don't keep organic farming principle in which organic farmer should enhance biological activity and crop rotation. This study was to compare nutrient input, recommendation, cropping system and organic product circulation between the early $20^{th}$ century and beginning of the $21^{st}$ century. The population of Korea has increased 7.3 times more than that of a century ago but cultivated land has been decreased during 100 years. The rice production in 2002 was 4.2 times higher than that of production in 1912. The input of N, P and K in 1907 on the basis of King's suggestion was 95.6kg/ha, 15.9kg/ha and 3.0kg/ha, respectively. Nitrogen came from excreta (40%), green manure (55%) and compost (5%) in the early 20th century. On the other hand, organic farmer input organic resources such as wood chip (30.1%), compost (27.8%), rice straw (14%) and others (25%) these days. In terms of nutrient balance calculated nutrient and absorption by plants, organic rice farmer apply excessive nitrogen and phosphorus to the soil. They was used to put $7{\sim}10$ times more nitrogen than that of a century ago. Nutrient recommendation was similar in N and P between early 20th century and early $21^{st}$ century. Farmers in both century did not rotate crops in the field. Today, organic farmers engaged in more continuous cultivation than in early 20th century. Farmers in the early $20^{th}$ century produced locally, consumed locally the agricultural products, but organic farmers in the $21^{st}$ century produce the organic product in the local farmland and consumed in the large city and also a lot of foreign organic products have been imported in recent year.

• 한국토양비료학회지
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• 제48권6호
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• pp.751-760
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• 2015

Management of renewable organic resources is important in attaining the sustainability of agricultural production. However, nutrient management with organic resources is more complex than fertilization with chemical fertilizer because the composition of the organic input or the environmental condition will influence organic matter decomposition and nutrient release. One of the most effective methods for estimating nutrient release from organic amendment is the use of N mineralization models. The present study aimed at parameterizing N mineralization models for a number of organic amendments being used as a nutrient source for crop production. Laboratory incubation experiment was conducted in aerobic condition. N mineralization was investigated for nineteen organic amendments in sandy soil and clay soil at $20^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$. N mineralization was facilitated at higher temperature condition. Negative correlation was observed between mineralized N and C:N ratio of organic amendments. N mineralization process was slower in clay soil than in sandy soil and this was mainly due to the delayed nitrification. The single and the double exponential models were used to estimate N mineralization of the organic amendments. N mineralization potential $N_p$ and mineralization rate k were estimated in different temperature and soil conditions. Estimated $N_p$ ranged from 28.8 to 228.1 and k from 0.0066 to 0.6932. The double exponential model showed better prediction of N mineralization compared with the single exponential model, particularly for organic amendments with high C:N ratio. It is expected that the model parameters estimated based on the incubation experiment could be used to design nutrient management planning in environment-friendly agriculture.

• 현장농수산연구지
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• 제12권1호
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• pp.3-10
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• 2010

In order to promote the growth of the trees, it is the most important to fertilize efficiently. The organic nutrient "Green-one" which list public notification number 08-organic-3-112" was registered in Rural Development Administration. The "Green-one" is the environment friendly organic nutrient with new concept which is used in planting and maintenance of the trees. The "Green-one" makes the tree grow actively. Also it has a function of the anti germ and sustainable fertilizer effect. In conclusion, "Green-one" promoted the growth of P. thunbergii excellently. Expecially the growth of the root increased. The concentration of "Green-one" dilution was more better 100 times than 300 times in trees grow. This research can apply with the test of fertilizer efficiency in landscape trees.

• 한국유기농업학회지
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• 제19권spc호
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• pp.165-168
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• 2011

An organic apple (Malus ${\times}$ domestics Borkh.) orchard was established to study the interaction effects of ground cover management systems (GMS) and nutrient sources (NS) on soil and tree nutrient status and tree growth. Trees received one of four GMS: 1) green compost (GC), 2) wood chips (WC), 3) shredded paper (SP), and 4) mow-and-blow (MB). Across all GMS, one of three NS was applied: A) a commercial organic fertilizer (CF), B) poultry litter (PL), and C) control (NF). Overall, GMS had greater effects on the variables than did NS. GC mulch supplied greater nutrients, followed by WC, SP, and MB mulches. SP trees had lower foliar [N] in the first two years than the GC and WC trees. GC-and WC-treated trees had larger trunk cross sectional area than the SP and MB trees.

• 해양환경안전학회지
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• 제27권5호
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• pp.630-638
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• 2021

본 연구에서는 와편모조류 Alexandrium affine(LIMS-PS-2345)의 생장에 미치는 용존태 무기 및 유기 영양염의 영향을 조사하였다. 영양염 흡수 동력학 실험에서 A. affine의 최대흡수속도(ρ_max)와 반포화상수(Ks)는 질산염에서 77.0 pmol/cell/hr과 17.6 μM, 인산염에서 15.5 pmol/cell/hr과 3.88 μM로 산출되어, 무기영양염에 대하여 높은 요구량 및 낮은 친화성을 가지고 있는 것으로 나타났다. 유기 영양염에 따른 A. affine의 생장속도를 확인한 결과, 유기 질소 urea, glycine와 유기 인 adenosine triphosphate(ATP), glycerol phosphate(Glycerol-P) 첨가구에서 무기 영양염 첨가구의 70 % 이상 생장속도를 보였다. 따라서 낮은 무기 영양염 환경에서 A. affine의 우점화와 종간경쟁에서 우위를 위해서는 용존태 유기 영양염의 이용이 필요할 것으로 생각된다.

• 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.

• 한국환경농학회지
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• 제27권3호
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• pp.267-273
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• 2008

안전농산물에 대한 국민의 관심 증대와 농업환경자원의 유지 보전을 위한 지속적인 농업생산 방안으로 친환경농업 육성의 필요성이 증대되어 왔다. 이에 우리나라에서는 친환경 농업이 빠르게 성장하여 1999년 1300호였던 인증농가가 2007년에는 100배 증가하여 13만호에 이르고 있다. 그러나 친환경농업의 빠른 증가 추세에도 불구하고 친환경농업이 농업생태계에 미치는 영향에 대한 정량적인 연구는 미흡한 실정으로 친환경농업의 올바른 확산을 위해서는 농업생태계에 미치는 영향을 규명하고, 지속가능성을 정량화하는 연구가 필요하다. 이에 친환경농업의 지속가능성을 평가하고자 2006년부터 2007년까지 완주군 고산면 광역친환경농업단지 벼유기농업단지에서 쌀생산 시 에너지효율 및 양분수지를 조사하였다. 그 결과 벼유기농업단지가 관행논보다 에너지효율은 낮았으나 재생가능한 에너지 자원을 사용하는 유기농법이 화학비료나 농약을 사용하는 관행농법에 비하여 자원이용의 지속가능도는 높았다. 또한 벼유기농업단지는 과량의 축분퇴비 시용으로 토양 내 인산과 칼륨이 과다 축적되어 있으므로 축분 퇴비의 시용량을 줄이고 질소대비 인산과 칼륨의 함량이 비교적 낮은 자운영 등을 이용한 시비개선이 필요할 것으로 판단된다.

• 한국유기농업학회지
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• 제8권2호
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• pp.97-110
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• 2000

An organic agriculture should be managed by mixed farming in farm unit as a closed recycling system. Due to restricted purchased of fertilizers from outside, organic farmer has to deal with limited amount of nutrient source in farm unit. Especially the supply of the essential nutrient, nitrogen, mostly depends on legumes fixing nitrogen optimizing the site-adapted crop rotation. Dynamics of humus and metabolic plant carbon and active soil carbon compartment in active and passive humuspool by rotation system was explained, and dynamics of potentially mineralizable nitrogen in organic nitrogen and biomass was discussed. It was also discussed comparison of ammonia emission, potential greenhouse effect, primary energy input, acidification potential, CO2 emission between organic and conventional farming, the nitrate-nitrogen dynamic in the soil profile by organic, integrated and conventional farming system. In conclusion, it was suggested for Korean Organic Agriculture that the importance of legumes and green manures in rotation system for increase/maintenance of soil ferfility, and was pointed out the need of investment for environment impact of Korean organic farming implement.