• Korean Journal of Soil Science and Fertilizer
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• v.12 no.3
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• pp.153-167
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• 1979

Proposal on the ways to determine the optimum levels of nutrients application on rice to maximize the yield was made paying attention on the desirable ratios among the major nutrients including N (organic matter) K, $SiO_2$, Ca, Mg. Following are the summary of the discussion. 1. For the higher yields, the balanced nutrients absorption is important. 2. Silica plays an important role in leading the applied N to increased yield. 3. Level of N application should be determined taking account of soil organic matter and abailable silicate contents. The higher the ratio of $SiO_2$/O.M. the more N can be applied for higher yield. 4. Different rice cultivars responds to the ratio of $SiO_2$/O.M. in soils, in different manner, in translating the applied N into yield. 5. By altering the ratio of $SiO_2$/O.M. through the application of silicate fertilizer or organic matter, the requirement of N in accordance with varietal characteristics can be determined. 6. When amount of N determined by above mentioned approaches, level of K application can be determined upon the basis of the ratio of $K/\sqrt{Ca+Mg}$ in soils.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.6
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• pp.372-380
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• 2002

This study was conducted to investigate the changes of soil properties for potato and Chinese cabbage after application adding phosphorus and potassium fertilizers in the mounded highland soil from 1999 to 2001. Experimental plots were designed with control(NPK+Lime+Compost) and chemical improvement(Control+Application adding P and K). Mounded soil before field experiment of first year(1999) was low in organic matter, available phosphorus and exchangeable potassium, and the soil texture was loamy sand soil. After 3 years, the contents of soil organic matter increased a little, and available phosphorus and exchangeable potassium contents were remarkably increased. The crop growth in chemical improvement plot was better than control plot. Yield of chemical improvement plot in comparison with control plot was increased by 5~22% for potato and 6~25% for Chinese cabbage after 2~3 years.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.541-545
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• 2010

식생이 소실된 산불 피해 지역에서 유실되는 토양의 식생회복에 따른 정량적인 변화를 파악하고, 사면토양과 유실토양의 성분분석을 수행하여 이화학적 특성을 파악하고자 한다. 산불 이후 10개의 조사구에서 강우에 의해 유실토양의 양을 측정한 후 토양을 건조시켜 보관하였다. 토양의 입도분석, 유기물함량, 건조밀도 등을 조사하였다. 그리고 전처리한 토양수는 ICP를 이용하여 Fe, Mn, P, Al, Zn, Na, Mg, K, Ca의 성분분석을 수행하였다. 산불 이후 시간경과에 따른 조사구별 식생 회복은 빠른 지역과 느린 지역으로 크게 구분한다. 재생이 불량한 지역은 재생이 왕성한 지역에 비해 상대적으로 많은 양의 토양이 유실되었다. 사면토양의 성분분석 결과 재생불량 지역의 성분함량이 가장 작았으며, 재생왕성 지역은 비피해지에 비해 성분함량이 대체로 높았다. 유실토양의 성분분석 결과 식생회복이 느린 조사구에서 영양염류 함량이 대체로 낮았다. 그러나 식생회복이 느린 조사구에서 많은 양의 토양이 유실되기 때문에 정량적인 영양염류의 소실량은 가장 많았다. 따라서 지표식생이 없는 지역은 다량의 토양유실로 인해 다량의 영양염류가 소실되어 식생 재생을 더디게 만드는 것으로 판단된다.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.2
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• pp.190-198
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• 2008

In this stduy, the column experiments were carried out assuming the soil was contaminated by leakage of gasoline containing MTBE from USTs and pipes around gas stations. Then, characteristics of MTBE transport in the soil were investigated using CXTFIT program. The column experiments with different soil properties, moisture content, organic matter content and flow rate were carried out. Some parameters(D, R, $\beta$, $\omega$) used in two-site non-equilibrium adsorption model were obtained from measuring the MTBE concentration in injection-liquid and in effluent and using CXTFIT program. In addition, The characteristics of MTBE transport in the soil was found using BTCs and obtained parameters. Consequently, the advection decreased as the increase of the content of fine particle and organic, while the MTBE transport by advection was enhanced as increasing flow rate and moisture content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.1
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• pp.49-55
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• 1997

For the labor-saving cultivation of barley in rice-barley double cropping system in paddy field, a series of expriments on the effect of rice straw application were carried out at the National Yeongnam Agricultural Experiment Station from 1992 to 1993. The affection of phenol compounds released from fresh rice straw could be lessened when seeded under rice straw in the soil and that made emergence rate increase by 11％, compared with that on application on the rice straw. Although utilization of rice straw as an organic material caused the poor growth of barley in early stage, it could be enhanced the culm breaking strength. On this reason, affected by rice straw, grain yield was increased from 8％ in common barley and up to 20％ in malting barley. The more nitrogen, CaO$_2$2 and SiO$_2$ applied, the more decomposition of rice straw accelerated from 2％ to 6.9％. On the application of rice straw as an organic material in malting barely cultivation, the content of crude protein was decreased while 1,000-grain-weight and grain assortment was increased.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.123-131
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• 2005

This study was focused on adsorption, leaching, photolysis, and hydrolysis of the fungicide procymidone in soils. Adsorption type of procymidone on three different soil were well fitted to Linear and Freundlich isotherm. Distribution coefficients (Kd) were ranged from 2.75 to 12.18 and Freundlich isotherm Kf value $1.99{\sim}9.98$, 1/n value $0.74{\sim}0.89$. Desorption rates were $20.1{\sim}34.0%$ (Namgye), $26.3{\sim}44.6%$ (Jigog) and $31.6{\sim}50.9%$ (Baegsan series) and desorption hysteresis were $0.65{\sim}0.79,\;0.55{\sim}0.73\;and\;0.49{\sim}0.68$. Procymidone seemed to be stable to photolysis in acidic and neutral solutions but hydrolyzed rapidly in alkaline solution. Considering leaching properties procymidone mobility low in soils.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.67-71
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• 1997

To grasp the physico-chemical properties on the management groups of upland soil, the data obtained from the detailed soil survey which conducted from 1964 to 1979 by Agricultural sciences Institute, were analyzed and classified. The clay content in A horizon soil was low in sandy textured and well adapted types and high in heavy clayey type, and that in B horizon was lowest in volcanic ash type and highest in heavy clayey type. High organic matter content was found in the volcanic ash and plateau type. The correlations among soil physico-chemical properties were significant. Especially canon exchange capacity of B horizon soil was highly correlated with the content of available water, clay, silt and organic matter positively.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.466-466
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• 2023

전세계적으로 2050년까지 탄소 배출량을 0으로 만들기 위한 탄소중립을 선언하였고, 우리나라에서는 온실가스 감축 목표 달성을 위해 논물관리기술 확산, 가축분뇨 자원순환 등 농업 분야 탄소 저감 계획을 수립하였다. 특히, 논물관리기술을 통한 탄소 저감 목표를 달성하기 위해서는 지역별 적합한 논물관리기술 모델이 개발되어야 한다. 이에 본 연구에서는 강원도 지역에 적합한 논물관리기술 모델 개발을 위해 강원도 원주시 일대 6개의 시험포를 조성하여 메탄 발생량을 모니터링 하였다. 각 시험포는 상시담수(S1), 4주 중간 물떼기+얕게 걸러 대기(S2), 4주 중간 물떼기+얕게 대기(S3), 3주 중간 물떼기+얕게 걸러 대기(S4), 2주 중간 물떼기+얕게 걸러 대기(S5), 2주 중간 물떼기+얕게 대기(S6)로 논물관리기간을 다르게 설정하였다. 그리고 각 시험포에는 메탄 발생량 모니터링을 위해 각각 3개의 챔버와 논물관리를 위한 자동물꼬조절장치를 설치하였다. 메탄발생량 모니터링은 2022년 5월부터 2022년 9월까지 총 5개월 동안 25회 진행하였다. 메탄 발생량 모니터링 결과 S1은 423.1 kg/ha, S2는 348.4 kg/ha, S3은 396.4 kg/ha, S4는 164.7 kg/ha, S5는 347.9 kg/ha, S6은 234.1 kg/ha 의 메탄이 배출된 것으로 분석되었다. 분석결과와 같이 S1에서 메탄 발생량이 가장 많았으며, S4에서 가장 적게 발생한 것으로 분석되었다. 논에서 발생되는 메탄에 영향을 주는 인자는 토양 유기물, 토양 산도 등이 중요한 요인으로 알려져 있으며, 이앙 전과 수확 후 토양분석을 진행한 결과 시험포별 인자별 변화량 차이가 나타났다. 따라서 장기적인 모니터링을 통해 논물관리기술에 따른 토양유기물 및 토양 산도 변화에 대한 보완이 필요할 것으로 판단되며, 지속적인 메탄 발생량 모니터링을 통해 강원도 지역에 적합한 논물관리기술을 적용해야 할 것으로 보여진다.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.5
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• pp.293-303
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• 2004

This experiment was conducted to investigate the direction or orientation of clay particle movement in argillic horizons (Bt) for clarifying the soil classification of soils. Soil samples were collected from 22 soil series containing Bt horizons. Physical and chemical characteristics and mineral and chemical compositions of clay in the soils were analyzed. Micoromorphological characteristics of the Bt horizons were also investigated with thin sections of the natural undisturbed and oriented soil samples. Average clay content in the Bt horizons was 28% and 1.33 times higher comparing to that in the surface layer. Soil pH was higher, but cation exchange capacity (CEC) and organic matter content were lower in Bt horizon than those in the surface layer. There was an evidence of clay accumulation in Bt horizons of all soil series examined except Bangog series. Although there was an increase of clay content in the horizons in Bangog series, the clay was not originated from illuviation process. The translocation of clay was in the order of an 2:1 expandable clay minerals > 2:1 non-expandable clay minerals > 1:1 clay minerals. The illuvial substances in argillic horizon were composed with clay, amorphous iron and opaque mineral. The micoromorphological features of Bt horizon were void coating, channel infilling and grain coating. There was an apparent boundary between clay coating and the groundmass in residuum and colluvium, but Bt horizon of alluvium was composed of a skew plane amputated by the physical operation.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.96-106
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• 1998

Rice plants were grown for 42 days in the specially made micro-ecosystem(pot) containing two different soils treated with fresh and 60-day-aged residues of [$^{14}C$]quinclorac, respectively, to elucidate the behaviour of the herbicide quinclorac residues in the soils. Amounts of $^{14}CO_{2}$ evolved from two soils treated with different residues with and without vegetation were all less than 2.2% of the total $^{14}C$, indicating that there was little microbial degradation of quinclorac in soil. $^{14}C$-Radioactivity absorbed and translocated into rice plants from soil A and B containing fresh quinclorac residues was 8.4 and 24.2%, respectively, of the originally applied $^{14}C$, while 5.5 and 17.7%, in aged residue soils. These results indicate that larger amounts of $^{14}C$ were absorbed by rice plants from soil B with less organic matter and clay than soil A, and the uptake of [$^{14}C$]quinclorac and its degradation products decreased with aging in soil. After 42 days of rice growing, 84.5 and 61.8% of the $^{14}C$ applied freshly to soil A and B, respectively, remained in soil, whereas, in the case of aged soils, 86.3 and 67.7% of the $^{14}C$ applied did. Meanwhile, without vegetation, more than 98.3% of the $^{14}C$ applied, in both fresh and aged residues, remained in soil, suggesting that quinclorac was relatively persistent chemically and microbiologically. Most of the non-extractable soil-bound residues of [$^{14}C$]quinclorac were incorporated into the organic matter and largely distributed in the fulvic acid portion.