유박의 줄뿌림 시비가 옥수수 생육 및 양분이용효율에 미치는 영향

옥정훈,조정래,이병모,안난희,신재훈,이연 한국유기농업학회 2016 韓國有機農業學會誌 Vol.24 No.4

This study aimed at improving the method of oil cake application in maize. The experiment was conducted during 2 years at NAS (National Institute of Agricultural Sciences) experimental field, located in Wanju-kun, Jeollabuk-do. Growth factors and nutrient use efficiency were evaluated depending on oil cake application depth, placement, and application rate. Difference in oil cake application method and depth was tested in 2012 and different placements of oil cake application were compared in 2013. Plant height, SPAD value, and dry weight of stem and corn were investigated. SPAD value, dry weight of stem and corn were significantly higher in oil cake banding treatment (OB5, 5 cm depth) as compared to others application methods, i.e. spreading (OS0), deep banding (OB10) and banding + spreading (OB5S). In addition, dry weight of stem and corn of banding treatments (OBL, OBLL) on rhizosphere and in between row (OBR) were higher than spreading treatment (OSP). Furthermore, in case of reduced application rate in additional fertilization did not decrease dry weight of corn and increased nutrient use efficiency. Therefore, it is concluded that banding application in 5 cm-depth and rhizosphere can improve growth and nutrient use efficiency in maize production.

시설재배지에서의 영양염류 유출 특성

옥정훈,이근후,유찬 경상대학교 농업생명과학연구원 2006 농업생명과학연구 Vol.40 No.3

중량식 라이시미터에서 물관리에 따른 배추, 옥수수의 적정 및 최소 물 필요량 산정

옥정훈,한경화,허승오,황선아,김동진 한국농림기상학회 2020 한국농림기상학회지 Vol.22 No.3

본 연구에서는 중량식 라이시미터를 이용하여 토양 및 물관리 방법에 따라 배추와 옥수수 재배기간 동안 물수지를 평가하였으며, 작물 생산성과 물 부족 상황을 고려하여 작물 수분스트레스 계수와 최소 물 필요량을 산정하였다. 2018 년 배추 재배는 정식 2 주 후 빈번한 강우로 인해 관개가 실시되지 않아 무관개구와 적습관개구의 관개량 차이가 없었으며, 생산량 차이 또한 나타나지 않았다. 2018 년 배추 재배를 제외하고 배추와 옥수수 재배에서 적습관개구가 무관개구보다 생산량이 높게 나타났으며 대체적으로 증발산량 또한 높게 나타났다. 생산량과 증발산량은 밀접한 관련이 있으며 바이오매스 증가에 따라 증산작용이 활발해짐을 알 수 있었다. 작물 수분스트레스 계수는 배추 중기 0.8, 후기 0.8, 옥수수 중기 0.8, 후기 0.5로 산정되었다. 배추와 옥수수의 최소 물 필요량(2017 년 배추 196.2 mm, 2018 년 옥수수 321.0 mm)은 적정 물 필요량(배추 239.4 mm, 2018 년 옥수수 466.9 mm) 대비 각각 82.0%, 68.8% 수준으로 나타났다. 이러한 산정 결과는 물부족 시기에 최소 관수량을 확보하여 작물 재배를 위한 물관리의 기초자료로 활용할 수 있을 것으로 생각된다. In this study, we performed to evaluate the water balance during the cultivation of Chinese cabbage and maize according to the soil type and water management method using weighable lysimeters, and to estimate the crop water stress coefficient and minimal water requirement by considering crop productivity and water deficiency. In 2018, Chinese cabbage cultivation period was not irrigated due to frequent rainfall two weeks after planting, so there was no difference in irrigation amount between the non-irrigated and the irrigated and little difference in crop yield. Excluding the Chinese cabbage cultivation in 2018, in the cultivation of Chinese cabbage and maize, the crop yield of irrigated plots was higher than that of non-irrigated plots. The evapotranspiration of irrigated plots was also generally higher than non-irrigated plots. Crop yield and evapotranspiration are closely related, and transpiration is active as biomass increases. The crop water stress coefficients in the middle and the late stage were 0.8 and 0.8 for Chinese cabbage and 0.8 and 0.5 for maize, respectively. The minimal water requirements for Chinese cabbage and maize were 82.0% and 68.8%, respectively, compared to the optimal water requirements (239.4 mm for Chinese cabbage and 466.9 mm for maize). These results can be used as basic data for water management for crop cultivation by securing the minimum amount of irrigation in case of water deficiency.

토양수분관측망을 활용한 토양수분의 실측값과 추정값 상관성 평가

옥정훈,김동진,한경화,정강호,이경도,장용선,조희래,황선아 한국농림기상학회 2019 한국농림기상학회지 Vol.21 No.4

Soil moisture monitoring is an important task to cope with climate change, and soil water prediction can provide large-scale soil moisture information. Therefore, this study was conducted to evaluate the relationship between the measured and predicted soil water content, and to estimate the correlation between the soil characteristics and soil water content. The selected sites in soil moisture monitoring network were 76, and the soil with high sand content (sand, loamy sand, and sandy loam in soil texture) accounted for 77% of the total. Organic matter and bulk density were 0.03 to 3.50% and 1.01 to 1.69 Mg m-3, respectively. Predicting values of field capacity and wilting point were lower than the measured soil water content, and the correlation coefficient between the measured and predicted values were low as 0.548 to 0.748. However, a significantly high positive correlation (p<0.01) found between the measured and predicted soil water content. Soil water (field water capacity and wilting point) content was highly positively correlated with silt, clay, and organic matter (p<0.01) and highly negatively correlated with sand (p<0.01). 기후변화 대응을 위한 토양수분 관리는 중요한 과제이며, 최적의 토양수분 함량을 예측할 수 있다면 대단위 토양수분 정보를 제공할 수 있다. 본 연구에서는 포장용수량 및 위조점의 실측값과 추정값에 대한 상관관계를 분석하였으며, 토양특성 인자와 토양수분 간 상관성을 조사하였다. 선정된 토양수분관측망 지점은 76 개이며, 모래함량이 높은 사토, 양질사토, 사양토가 77%를 차지하였으며, 유기물은 0.03∼3.50%, 용적밀도는 1.01∼1.69 Mg m-3 범위로 조사되었다. 포장용수량 및 위조점의 추정값은 실측값과 상관계수가 낮고 실측값보다 과소 평가되었으나 추정값과 실측값 간에는 고도로 유의한 정의상관관계(p<0.01)가 나타났다. 토양수분(포장용수량 및 위조점)은 미사, 점토, 유기물과는 고도로 유의한 정의상관(p<0.01)이었으며, 모래와는 고도로 유의한 부의상관(p<0.01)이었다. 하지만 본 연구에서 조사된 토양수분관측망 토양은 농업기상대 설치를 위하여 인위적으로 조성된 지점이 포함되어 있어 일반농경지 토양 특성을 그대로 반영하기 다소 어려움이 있다. 따라서 토양수분 측정 조사지점을 농경지까지 포함하여 표본수를 확대하고 토양 인자를 적절하게 활용할 경우 국내 실정에 맞는 토양수분 추정식을 도출할 수 있을 것으로 기대된다.

The Study of Improvement of Measurement Precision on Bulk Density, Soil Hardness and Air Permeability in Upland Soils

옥정훈,한경화,조희래,장용선,서영호,정강호,이협성,김기선 한국토양비료학회 2017 한국토양비료학회지 Vol.50 No.5

The measurement based on reliable standard operating procedures (SOPs) is important for consistentinformation. The objective of this study is to investigate reliable SOPs of soil physical methods, includingcore method for bulk density, Yamanaka hardness, and air permeameter method for air permeability. Thecoefficients of variation in bulk density (core method), Yamanaka hardness, and air permeability were rangedof 1~6%, 8~13%, and 10~84%, respectively. The variation in situ measurement such as bulk density, hardness,and air permeability due to spatial variability at measuring site was larger due to the number of replicates,organic matter content, and soil texture. Nevertheless, air permeability had different values as differentnumber of replicates, and thus, it is thought that more replicates can result in higher reliability. It suggestedthat investigation of soil physical properties for the target sites should required to consider about soil texture,organic matter content, and number of replications before measurement. In conclusion, core sampling for bulkdensity measurement in upland soil recommended to perform in 3 repetitions with 2 inch core, and 3 inch coresampling for higher organic matter content.

Weighable Lysimeter Study for Water Balance Estimation of Chinese Cabbage in the Fall Season

옥정훈,한경화,조희래,황선아,김동진 한국토양비료학회 2019 한국토양비료학회지 Vol.52 No.4

In this study, we estimated and compared the water balance and total water requirement for Chinese cabbage cultivation in the fall season using weighable lysimeters. The water balance of input and output were investigated according to by two different upland soils. In Chinese cabbage cultivation, the total input was different in precipitation and irrigation, and total output was different in evapotranspiration and drainage. The estimated total water requirement for Chinese cabbage cultivation in the fall season in 2017 and 2018 were lower as compared to that in normal years (1981 - 2010) because of large amount rainfall around transplanting in 2017 and several rainfall events in 2018. The total water requirements for normal years, 2017, and 2018 were 147.2 mm, 143.6 mm, and 135.5 mm, respectively, compared to the normal years, it decreased by 2% in 2017 and by 8% in 2018. The weighable lysimeter has provided a useful tool for the water balance and water requirement estimation of Chinese cabbage and could be developed for several crops in upland condition based on obtained data.

신규 개간 유기농경지에서 가축분 퇴비와 녹비작물 연용에 따른 밭 토양의 이화학적 특성 변화 모니터링

옥정훈,조정래,이병모,안난희,신재훈 한국유기농업학회 2015 韓國有機農業學會誌 Vol.23 No.4

This study was conducted to evaluate the effect of organic inputs on soil properties in a newly reclaimed organic soils. The soil of the experiment site was very low in soil fertility and the physico-chemical properties were poor. Several organic input treatments with different source of nutrient were placed, including compost in combination with green manures for organic agricultural practices, chemical fertilizers for conventional agricultural practices, and control without fertilizer. The experiment was conducted with continuous cropping system during 3 years. The chemical properties concentration in compost+green manure treatment was increased continually compare to control and chemical fertilizer treatment, and closed to the recommended rate of fertilizer. The organic matter value for compost+ green manure treatment was increased from 0.86~0.96% to 2.00~2.29% by continuous nutrient supply of compost and green manure. However, further investigation on increasing of organic matter value for 3 years is necessary to monitor carefully during the long-term because it will help to clarify the all mechanisms of organic matter on organic input application way. The available phosphate value for compost+ green manure treatment was generally increased from 21.9~27.1 mg/kg to 182.0~ 394.1 mg/kg. In case of exchange cation, the concentration for compost+ green manure treatment was increased during 2 years within the range to the recommended rate of fertilizer, however, it is expected to cause a rather over supply for 3 years.

밭토양 라이시미터에서 관개방법에 따른 토양수분의 이동변화 모니터링

옥정훈(Jung-hun Ok),한경화(Kyung-hwa Han),김동진(Dong-Jin Kim),장용선(Yong-seon Zhang),조희래(Hee-rae Cho),황선아(Seon-ah Hwang),이진희(Jin-hee Lee),김순선(Soon-sun Kim) 한국토양비료학회 2019 한국토양비료학회 학술발표회 초록집 Vol.2019 No.8

벼 2기작에서 작물재배시기에 따른 제초제의 유출특성 모니터링

옥정훈 ( Junghun Ok ),뉴엔하이도안 ( Nguyen Hai Doan ),와타나베히로즈미 ( Hirozumi Watanabe ),당궉듀엣 ( Dang Quoc Thuyet ) 한국농공학회 2013 한국농공학회 학술대회초록집 Vol.2013 No.-

아열대 기후 등에서 이루어지고 있는 벼 2기작재배에서 비점오염원인 농약의 유출특성을 파악하기 위하여, 논에서 봄과 여름의 작물재배시기에 따라 두 제초제 butachlor와 pyrazosulfuron-ethyl의 농약유출특성을 온도변화에 따라 조사하였다. 주요 목적을 수행하기 위하여 세부적인 연구항목으로 실제 논 환경에서 작물재배시기에 따른 두 제초제의 농약유출특성 모니터링, 소형 라이시메타를 이용하여 인위적인 수문조건조절에서 작물재배시기의 온도 차이에 따른 두 제초제의 농약유출특성 모니터링, 온도 변화 및 자연광에 의한 두 제초제의 저감과정 실험 등을 수행하였다. 그 결과를 요약하면 다음과 같다. 실제 논 환경에서의 모니터링을 2년동안 수행하여 논에서의 물과 토양내의 두 제초제의 농도변화를 비교ㆍ분석했다. 현장 실험에서는 강우이벤트가 제초제 농도 및 손실에 주요한 영향 요인으로 작용하였다. 이에 따라, 실제 논에서 봄과 여름동안 농약유출특성에 대한 온도의 영향은 여러 환경요인으로 인하여 그 영향을 평가하는 것이 어려웠다. 온도에 따른 두 제초제의 농약유출특성을 명확히 평가하기 위하여 소형 라이시메타를 이용하여 인위적으로 수문조건을 컨트롤하여 봄과 여름작물재배시기 동안에 두 제초제의 온도 변화에 따른 영향을 알아보았다. 소형 라이시메타 실험에서는 여름에서 물 샘플에서의 두 제초제의 손실이 봄과 비교하여 보다 빠르게 일어났으며, 물 샘플에 두 제초제의 주요 손실은 온도차이에 의한 저감속도 차이에 의해서 이루어진 것으로 판단된다. 물 샘플에서의 두 제초제의 저감 과정을 여러 온도 조건 및 자연광 등에서 실험을 통하여 알아보았다. 그 결과로, 이 두 제초제에 대한 저감과정의 기여도는 온도 및 자연광 등에 따라 각각 다르게 영향을 받았다. 물 샘플에서 pyrazosulfuron-ethyl의 저감 속도는 온도의 증가에 의해 증가되었든 반면, butachlor경우에는 자연광에 의한 저감이 뚜렷하게 발생하는 것을 확인할 수 있었다.

중량식 라이시미터 활용 고추 재배시 비닐피복 여부에 따른 물수지 산정

옥정훈(Jung-hun Ok),이세인(Se-in Lee),허승오(Seung-oh Hur),오부영(Bu-yeong Oh),황선아(Seon-ah Hwang),손정우(Jeong-woo Son) 한국토양비료학회 2022 한국토양비료학회 학술발표회 초록집 Vol.2022 No.10