• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.223-227
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• 2007

This study was carried out to establish the reasonable level of nitrogen (N) fertilization based on soil nitrate nitrogen $(NO_3-N)$ content for cucumber (Cucumis sativus L.) under plastic film house. Cucumber plants were cultivated with standard and free N fertilization in eight soils which had various amount of $NO_3-N$ ranging from 67 to 343 mg/kg. The yield of cucumber was in the range of 1006 to 2369 g/plant depending on the nitrogen supplying capability of soils. The amount of $NO_3-N$ in the soil was negatively correlated with agronomic efficiency (AE) and N use efficiency (NUE). The critical level of soil $NO_3-N$ content for cucumber in N free fertilization was found to be about 260 mg/kg in Cate-Nelson analysis of variance between soil $NO_3-N$ and AE or NUE. Also the same critical soil $NO_3-N$ content was found in the yield and amount of N uptake of cucumber under N free fertilization. A standard N fertilization was required when soil $NO_3-N$ content was below 70 mg/kg. The optimal application rate of N fertilizer for cucumber in the soils containing $NO_3-N$ between 260-70 mg/kg could be recommended by the equation Y=-1.032X+269.2 (Y: N fertilization rate, kg/ha; X : soil $NO_3-N$ content mg/kg).

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.2
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• pp.103-110
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• 1993

This study was made to evaluate the chemical properties of 481 farmers' orchard fields in An-Seong area. And the reasonable ferilizer rates were recommended utilizing the result of soil analysis. The results are summarized as follows : 1. As the soil fertility status of collected soil samples were evaluated on the basis of temporary optimal range for each soil chemical properties, 12.7 to 49.6% of the total 481 farmers' fields were range for soil improvement. 2. The contents of chemical component have a tendancy to decrease with depth gradually from surface to subsoil. 3. According to the relationship between the contents of soil component in subsoil and those in surface soil, the fertility condition of subsoil could be estimated on the basis of analysis data of surface soil. 4. The multiple regression equation for pear yield prediction to the organic matter and exchangable calcium contents in the soil were obtained. 5. Referring the average value, distribution ratio compared to the optimum level for each soil chemical properties and standard fertilizer rate, the soil fertility status could be categorized as "High" "Medium" and "Low". For each category, the recommended amounts for NPK and organic matter application were established. 6. The recommended rates through soul fertility diagnosis were less than farmer's dosage in the range 7.1~7.7 kg/10a for N, 0.8~11.5 kg/10a for $P_2O_5$, 7.1~19.9 kg/10a for $K_2O$ and 90~116 kg/10a for lime.

• Korean Journal of Soil Science and Fertilizer
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• v.9 no.1
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• pp.25-31
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• 1976

The purpose of this investigation is to find out the effects on the changes of microflora and the effects on the inorganic nutrients of the fertilized soil and the non-fertilized soil under submerged condition with the treatment of butachlor at the levels of 250, 500, and 1000ppm respectively. The survey was made within the period of 72 days with 7-day intervals under the incubated condition. The result came out to be the following: 1. The Fluctuated changes of soil microflora A. Bacteria: The plots treated by 500ppm of butachlor in case of non-fertilized soil showed the decreasing tendency of bacteria until 21st day. But there were no effects on the other plots. The plots treated by 250ppm and 500ppm in case of fertilized soil showed decreasing tendency on the 7th day, and 1000ppm until 21st days. B. Actinomycetes: There was no effects on the actinotnycetes in case of the non-fertilized soil but the fertilized soil showed some decrease. In both cases, actinomycetes have generally shown a little increase according to the time passage. C. Fungi: In both cases of the fertilized soil and the non-fertilized soil, the plots treated by the media showed some decreasing tendency in comparison with the control plots. There was no change to the number of fungi according to the time passage. 2. The fluctuated changes of nutrient A. $NH_4-N$: The whole plots showed decrease of $NH_4-N$ by adding butachlor. The higher the intencity of butachiar showed the more decreasing tendency of $NH_4-N$. In case of the non-fertilized soil, the highest increase of $NH_4-N$ appeared from the 7th day to 14th day, but showed degrease thereafter. The increasing tendency was seen in case of the fertilized soil plots. B. $NO_3-N$: Decrease of $NO_3-N$ was shown in the whole plots by the treatment of media, and on the 44th day of cultivation almost none of $NO_3-N$ was detected. C. $NO_2-N$: Whole plots showed the number of $NO_2-N$ highest on the 35th day, and there were nothing measurable on the 44th day. D. Eh: On the fertilized soil, the condition of reduction went on strongly but on the non-fertilized soil, the condition of reduction kept on till 42nd day and oxidation appeared thereafter.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.246-250
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• 2003

In order to preserve the soundness of agro-ecosystem and products safety in agriculture, this study was evaluated environmental impact in relation to the INM (Integrated Nutrient Management) and IPM (Integrated Pest Management) at paddy fields at Ok-Chun and Yang-Pyung region. By introduction of INM with the application of BB(bulk-blanded) fertilizer based on soil analysis and IPM, the application rate of fertilizer was reduced to about $28.6{\sim}39.4%$ and the yield of brown rice was increased to about $3{\sim}10%$ compared to conventional practices. The concentrations of COD, $NH_4-N$, and $NO_3-N$ in irrigation water flowed to the environmental-friendly agriculture practices were 15.0, 0.67, and 1.39 mg/L, respectively. The concentrations of COD, $NH_4-N$, and $NO_3-N$ from paddy fields in drainage water were 12.4, 0.29, and 2.42 mg/L, respectively. The total number of the freshwater invertebrates was higher in field treated with fertilization by prescription with soil testing. Also, the population density of aquatic insects was higher than the other fields at both demonstration villages. In conclusion, it was possible to reduce the amount of fertilizer and agricultural chemicals application, and increase the yield of rice by application of the environmental-friendly agriculture practices.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.2
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• pp.86-94
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• 2006

The primary concern on fertilizer recommendations on paddy soils in Korea is not high rice yield but high rice quality, sustainable rice yield, and less environmental loads these days. Based on soil survey data, the paddy soils in Korea were classified into five large management types ; normal, sandy, immatured, poorly drained, saline soil. In order to establish the optimum level of nitrogen fertilizer to increase the rate of head rice yield, field experiments were conducted at 24 farmhouses throughout the country with nitrogen fertilizer treatment levels of 0, 50, 70, 90, 110, 140, $170kg\;ha^{-1}$ from 2003 to 2004. As the result of the experiment, the optimum rates of nitrogen fertilizer for improving rice quality were $90kg\;ha^{-1}$ in normal, sandy, and poorly drained soils, $100kg\;ha^{-1}$ in immatured soils, and $112kg\;ha^{-1}$ in saline soils where the content of NaCl in soil was below 0.1%. The optimum rates of nitrogen fertilizer were determined in view of head rice percent, protein content, and palatability value of rice.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.341-346
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• 1998

The effects of CaO, $CaO+MgSO_4$, and $CaO+MgSO_4$+compound fertilizers(NPK) on soil chemical properties of acidified forest soils were studied in Quercus spp. and Pinus rigida stands in Mt. Namsan and Mt. Surak in urban areas, and Kwangnung in a mountain area. The soil samples were collected in November 1995 after every year fertilization from November 1991 through April 1995. The fertilizations affected soil chemical properties. Soil pH increased after fertilizations compared with control. However, the effect was different between the stand types and the areas. Organic matter and total nitrogen content were not changed, while exchangable cations such as calcium and magnesium increased after fertilizations. However, these ration concentrations after fertilizer treatments were lower in P. rigida than in Quercus spp. stands. These rations also showed increased leaching characteristics more in the urban area than in the mountain area.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.5
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• pp.311-315
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• 2001

In order to improve a soil test-based fertilization model for nitrogen, the Mitscherlich-Baule-Spillman equation modified by Bray and his coworkers was introduced and tested for its possibility of application. The coefficients $C_1$ and $C_2$ in the equation A were calculated by applying 10 pot experimental results done by the National Institute of Agricultural Sciences and Technology. Then, a regression(B) between C_1 and x, the fertilizer level was estimated. log(Ymax-Y) = logYmax-$C_1x-C_2b$ (A) where Ymax : maximum yield. Y : yield without or with a limited amount of fertilizer applied, x : application level of fertilizer, b : content of a nutrient in soil, $C_1$ and $C_2$ : coefficients of x and b, respectively. log(0.05)=$-C_1x-C_2b$ (B) Fertilizer requirement calculated by the equation B was significantly correlated with the real level of fertilizer applied for 95 percentage of the maximum yield. A more extensive and precise study on $C_1$ and $C_2$ in the equation A in expected to improve significantly the fitness of soil analysis to the fertilizer recommendation.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.443-443
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• 2021

국내 하천, 호소에 유입되는 오염물질 중 30% 이상이 농업 활동 등으로부터 기인한다. 정부 부처는 '04년부터 농업 비점오염원 저감 대책을 수립·시행하고 있으나 농촌 인구 고령화, 열악한 재정환경, 관행화·고착화 된 농법 등으로 인해 주민참여 및 대책 적용의 한계가 있었다. 금호강 상류 보현산댐 유역은 대부분 임야로 고현천 등 상류 하천변에 사과원이 밀집되어 있다. 또한, 유역면적이 32.16km²로 좁고, 유로 연장 5km 이내로 짧으며 하천 경사가 급해 강우시 토양 유실량이 많고 유출속도가 빠르다. 이러한 유역 특성상 상류 사과원은 '16년 보현산댐 담수 이후 매년 반복적으로 발생하는 녹조 등 수질 문제를 초래하는 주요 비점오염원으로 지역사회 이슈가 되었다. 이에 따라 K-water는 낙동강수계관리위원회 환경기초조사사업의 일환으로 지역주민들과 논의를 통하여 댐 상류 사과원에 친환경농법(심층시비)를 적용하고 수질 개선 효과를 분석하였다. 심층시비는 과수 주변 토양 천공 후 퇴비를 시비하는 친환경농법으로 표층시비에 비해 초기 강우유출 오염물질량을 저감하고 퇴비 사용량도 줄일 수 있다. 금번 연구에서 실제 운영 중인 농지('19년 24천평, '20년 27천평)을 대상으로 심층시비를 시범적용한 결과, 퇴비 사용량은 표층시비의 50% 수준으로 감소하였고 과수 생육 및 품질에는 큰 영향이 없는 것으로 나타났다. 강우 시 유출농도는 표층시비 대비 TOC 5.0~41.3%, T-P 4.0~57.3% 감소했다. HSPF 유역 모델링 분석 결과, 전체 과수원 중 70% 농지에 심층시비를 적용한 경우, 하절기 유역 T-P 유입부하량이 5.0~6.8%(소유역 최대 28.2%) 감소하는 것으로 예측되었다. 본 연구결과를 바탕으로 심층시비를 확대 적용하고 유역 수질관리에 기여하고자 한다.

• Proceedings of the Mineralogical Society of Korea Conference
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• 1996.10a
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• pp.61-72
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• 1996

중국 토양표토의 유황함량은 27에서 967mg S/kg(평균 233.2mg S/kg, n=632)범위에 있다. 이중 홍토(Haplic Acrisols)와 황갈색토(Eutric Cambisols)는 양쯔 및 Huaihe강 사이에 중국 중앙에 분포하고 유황함량은 각각 146과 159mg S/kg이다. 황색 목장토(Gleyic Cambisols)와 회색 목장토(Umbric Fluvisols)는 가장 높은 전 유황함량과 가장 높은 유황공급력을 가지고 있으나 제일 인산석회 침출 유황함량(현지유효 유황함량으로 평가)은 가장낮다. 그러나 황갈색 및 홍토는 이와는 반대 특성을 지니고 있다. Shajiang 흑토(Calcic Vertisols)와 논토양(Mollic/Eutric Fluvisols과 Anthraquic 상)은 총 유황함량, 인산 침출 유황함량과 잠재 유황 공급력에서는 중간에 속하고 남부 Huaihe강에 걸쳐있는 논토양에서 유황함량은 재배기간중 균형 상태에 있으나 전(前)작물에서 특히 밀과 유채에서는 부족한 상태이다. 황산염($SO_4^{2-}$)은 토양중 상하로 이동 되면서 균형을 유지하여 토양 수분함량과 밀접한 관계가 있다. 따라서 제일인산칼슘 용액침출 유황 함량을 가지고 표토에서 유황의 과부족을 진단하기는 그리 쉬운 일이 아니다 중국에서 수행된 유황시비 시험에서 20개 작목에서 평균 $4.3-40\%$의 수량증수를 기록하였으며 유황시비는 증수뿐만 아니라 작물의 질을 개선하나 담배잎의 연소성은 유황함량과 부의 상관이 있다.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.280-289
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• 2003

The purpose of this study was to establish a model for recommendable application level of nitrogen fertilizer based on soil testing for summer chinese cabbage in highland. A field experiment was carried out with various nitrogen application levels in sand loamy soil with and without poultry manure compost. The application level of N in poultry manure compost plot was found to be $291kg\;ha^{-1}$ for maximum yield of chinese cabbage, and it was 87% of the required N application level, $335kg\;ha^{-1}$, for maximum yield of chinese cabbage in nonmanure plot. In the treatment of poultry manure, approximately $174kg\;ha^{-1}$ of N was required to obtain the same yield of chinese cabbage as the maximum yield obtained in the treatments without poultry manure application. Therefore, with poultry manure application, N application level can be reduced by 40%. Using these results, a new equation for N recommendation for chinese cabbage in highland soil was proposed. With the average organic matter content of $33g\;kg^{-1}$ in highland field, the application levels of N for chinese cabbage were in the range of $215-129kg\;ha^{-1}$, which means that 32.8-59.7% of current application amount of N fertilizer can be reduced.