• 한국작물학회:학술대회논문집
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• 한국작물학회 1998년도 춘계 학술대회지
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• pp.87-88
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• 1998

• 한국작물학회:학술대회논문집
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• 한국작물학회 2004년도 춘계 학술대회지
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• pp.292-293
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• 2004

• 한국작물학회지
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• 제48권4호
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• pp.308-315
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• 2003

A field experiment was conducted to investigate the performance of three legume species in a zero-tillage, non-fertilized rice field in a temperate zone. Before the experiment for 5 years, from 1995 to 1999, plant growth patterns of three legume species grown as over-wintering (October-May) cover crops on a paddy field were maintained to study N balance and $\textrm{N}_2$ fixation. Decrease in plant density accelerated from after winter to flowering from 1,090, 320, and 5 to 732, 232, and 6 plants $\textrm{m}^{-2}$ in Chinese milk vetch (CMV), white clover (WC), and hairy vetch (HV), respectively. Total dry weights of plants above-ground level were 0.05, 0.11, and 2.43 g $\textrm{plant}^{-1}$. in WC, CMV and HV respectively but steeply increased at ripening up to 0.77, 2.33, and 26 g $\textrm{plant}^{-1}$. The root dry weight of HV and CMV rapidly increased while in WC, root dry weight increased slightly towards flowering. The highest nodule numbers were recorded in CMV to April thereafter WC produced the highest. Nodule size was distributed within 7mm in CMV but it was larger in HV varying from 1 to 10mm. Shoot N (g $\textrm{m}^{-2}$) greatly increased from over-wintering to flowering in CMV, HV and WC and it ranged from 1.66, 0.5 and 1.92 to 12.6, 3.1 and 13.02 g $\textrm{m}^{-2}$, respectively. After wintering, the initial shoot N content (%) was more in CMV. Root N content (%) was constant or slightly decreased in HV and WC. Soil total N in the control plot (clean fallow) was the highest on Mar. 2 then decreased rapidly to flowering. Soil N content was constant in HV plots whereas it was low in WC plots for the entire growth period except just after winter. Maximum nitrogenase activities were 9, 37.8, and 131 mol $\textrm{C}_2\textrm{H}_4$ $\textrm{plant}^{-1}$ $\textrm{hour}^{-1}$. in CMV, HV, and WC, respectively. Nitrogenase activity showed a direct correlation with nodule number, size and fresh weight. As a cover crop preceding a rice crop, CMV is more suited to colder regions due to its earlier ripening characteristics. Hairy vetch and WC are recommended for regions with a mild winter and a long summer owing to their late ripening and great N fixation activity.

• 드라이브 ㆍ 컨트롤
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• 제20권3호
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• pp.15-24
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• 2023

The aim of this study was to measure and evaluate the exhaust emission factors of agricultural tractors. Engine characteristics and three exhaust emissions (CO, NO_x, PM) were collected under actual agricultural operating conditions. Experiments were performed on idling, driving, plow tillage, and rotary tillage. The load factor (LF) was calculated using the collected engine data, and the emission factor was analyzed using the LF and exhaust emissions. The engine characteristics and exhaust emissions were significantly different for each working condition, and in particular, the LF was significantly different from the currently applied 0.48 LF. The data distribution of exhaust emissions was different depending on the engine speed. In some conditions, the emission factor was higher than the exhaust emission standards. However, since most emission limit standards are values calculated using an engine dynamometer, even if the emission factor measured under actual working conditions is higher, it cannot be regarded as wrong. It is expected that the results of this study can be used for the inventory construction of a calculation for domestic agricultural machinery emissions in the future.

• Journal of Biosystems Engineering
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• 제23권5호
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• pp.427-438
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• 1998

In Korea, rotary implements are mainly utilized in the tillage operation. The attitude control system for rolling phenominon of tractors, which in caused due to uneven ground surfaces and sinkage of tractor wheels, is one of the most important control systems in agricultural tractors. The attitude control system of a rotary implement, attached on tractors, was designed and fabricated in this study. The control system was largely composed of four main units; a setting unit, a detection unit, a controller and a hydraulic unit. The implement was controlled by control signals from a computer proportional to controlled errors, on/off action of two directional solenoide valve and lift cylinder on the right lift rod. Response characteristic experiments for the control system fabricated in this study were carried out indoors and outdoors. The results of experiments showed the response characteristics sufficient to use as the attitude control system of rotary implements for agricultural tractors.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.373-382
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• 1993

A non-contact sensor for detecting distance from field surface to a predetermined location of a tractor will be useful to control precise height of implements such as tillage machinery, mowers etc.. An optical and an ultrasonic sensors were designed and fabricated . The indoor and outdoor experiments were conducted to obtain the static and dynamic characteristics of the two sensors at several moisture levels of four soils and on the soil surface with a designed shape. The results revealed that the optical sensor is unsuitable for soils with high moisture content but showed better detecting accuracy on the irregularity of soil surface.

• 한국잡초학회지
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• 제17권1호
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• pp.10-23
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• 1997

본(本) 연구(硏究)는 최근(最近) 우점화(優占化)되어 방제(防除)가 어려운 다년생잡초(多年生雜草) 올방개의 방제체계(防除體系)를 확립(確立)하기 위한 일환으로 괴경의 분포(分布) 및 괴경 형성특성(形成特性)을 구명(究明)하여 1993~1994에 시험(試驗)한 결과(結果)이다. 1. 올방개는 조식(早植)할수록 괴경형성수(塊莖形成數)가 증가(增加)하고 괴경중(塊莖重)도 증가(增加)하는 경향(傾向)이었으나, 이들 괴경(塊莖)은 주로 표층(表層)에 분포(分布)하였다. 2. 괴경(塊莖)의 토중분포(土中分布)는 0~10cm의 표층(表層)에 가장 많았고, 20cm 이하(以下)의 심토(深土)에는 10---- 내외(內外)의 괴경(塊莖)이 분포(分布)하였는데, 후기(後期)에 형성(形成)된 괴경(塊莖)들은 주로 표토(表土)에 분포(分布)하는 경향(傾向)이었다. 3. 경운(耕耘) 작업(作業)을 생략(省略)한 무경운(無耕耘) 정지(整地)및 무경운(無耕耘) 무정지구(無整地區)에서 괴경형성(塊莖形成)이 많아졌고, 무경운(無耕耘) 정지(整地)의 경우 0~10cm의 표층(表層)에서의 분포비율(分布比率)이 높았다. 4. 지하관정(地下管井)으로부터의 냉수관개(冷水灌漑)에 의하여 형성괴경수(形成塊莖數)는 약간 증대(增大)되는 경향(傾向)이었으나, 괴경(塊莖)의 크기는 현저히 감소(減少)되는 것으로 나타났다. 5. 착색(着色) 셀로판 필름을 이용(利用)한 차광(遮光)은 괴경중(塊莖重)과 맹아율(萌芽率)의 감소(減少)로 나타났는데, 특히 녹색(綠色)의 경우 괴경수(塊莖數)의 감소(減少)도 현저하여 차광효과(遮光效果)가 가장 크게 나타났다.

• 한국토양비료학회지
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• 제42권Spc호
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• pp.40-44
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• 2009

이 연구는 Rock-dust로 채워진 농업 용지(Technosol)의 환경에서 물이 보이는 침투성과 삼투성의 특정을 파악하고자 수행되었다. 이 실험은 A와 B 두 장소에서 이루어졌으며 피실험지의 토양층은 각각 4가지 층으로 분류되었다. 모든 토양층의 토성은 미사질 양토로 분석되었으며 장소 A의 가장 낮은 층에서만은 양질사토였다. 두 토양에서, 각 토양층에 대한 용적밀도는 $1.49g{\cdot}cm^{-3}$을 대체로 상회하였으며, 이는 통상적인 medium textured mineral soil의 $1.25g{\cdot}cm^{-3}$을 크게 웃도는 값이다. 경운 직후 측정된 장소 A의 표토는 이보다 낮았다. 두 토양 표면에서의 $P_2O_5$의 집적은 각각 1962 (A), 1613 (B)$mg{\cdot}kg^{-1}$이었다. 이러한 집적은 3.2~6.5번에 걸쳐서 $300{\sim}500mg{\cdot}kg^{-1}$만큼 작물 생장에 알맞은 규모로 이루어졌다. 두 토양 표변에서의 Infiltration rate는 3.54 (A), 2.85 (B)$cm{\cdot}hr^{-1}$이었으나 각 토양층에 대한 percolation rate는 0.3 이하 (A), 0.003 이하 (B)$cm{\cdot}hr^{-1}$였다. 이러한 결과들은 표토가 동의 작용을 받은 반면 심토는 암분의 농업용지 형성 과정에서 생겨난 구조적인 문제인 바위 부스러기의 응집과 농업기계에 대한 다짐현상으로 인한 것임을 의미한다고 여겨진다.

• 한국농공학회지
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• 제22권4호
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• pp.108-114
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• 1980

A deterministic conceptual erosion model which simulates detachment, entrainment, transport and deposition of eroded soil particles by rainfall impact and flowing water is presented. Both upland and channel phases of sediment yield are incorporated into the erosion model. The algorithms for the soil erosion and sedimentation processes including land and crop management effects are taken from the literature and then solved using a digital computer. The erosion model is used in conjunction with the modified Kentucky Watershed Model which simulates the hydrologic characteristics from watershed data. The two models are linked together by using the appropriate computer code. Calibrations for both the watershed and erosion model parameters are made by comparing the simulated results with actual field measurements in the Four Mile Creek watershed near Traer, Iowa using 1976 and 1977 water year data. Two water years, 1970 and 1978 are used as test years for model verification. There is good agreement between the mean daily simulated and recorded streamflow and between the simulated and recorded suspended sediment load except few partial differences. The following conclusions were drawn from the results after testing the watershed and erosion model. 1. The watershed and erosion model is a deterministic lumped parameter model, and is capable of simulating the daily mean streamflow and suspended sediment load within a 20 percent error, when the correct watershed and erosion parameters are supplied. 2. It is found that soil erosion is sensitive to errors in simulation of occurrence and intensity of precipitation and of overland flow. Therefore, representative precipitation data and a watershed model which provides an accurate simulation of soil moisture and resulting overland flow are essential for the accurate simulation of soil erosion and subsequent sediment transport prediction. 3. Erroneous prediction of snowmelt in terms of time and magnitute in conjunction with The frozen ground could be the reason for the poor simulation of streamflow as well as sediment yield in the snowmelt period. More elaborate and accurate snowmelt submodels will greatly improve accuracy. 4. Poor simulation results can be attributed to deficiencies in erosion model and to errors in the observed data such as the recorded daily streamflow and the sediment concentration. 5. Crop management and tillage operations are two major factors that have a great effect on soil erosion simulation. The erosion model attempts to evaluate the impact of crop management and tillage effects on sediment production. These effects on sediment yield appear to be somewhat equivalent to the effect of overland flow. 6. Application and testing of the watershed and erosion model on watersheds in a variety of regions with different soils and meteorological characteristics may be recommended to verify its general applicability and to detact the deficiencies of the model. Futhermore, by further modification and expansion with additional data, the watershed and erosion model developed through this study can be used as a planning tool for watershed management and for solving agricultural non-point pollution problems.

• 한국초지조사료학회지
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• 제43권1호
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• pp.28-34
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• 2023

본 시험은 하계자생작물인 사료 피 '제주피', 강아지풀(국내 생태형), 바랭이(국내 생태형)의 파종량에 따른 생육특성 및 생산성을 조사하기 위해 충청남도 천안시 소재 국립축산과학원 축산자원개발부 초지사료포장 무경운 논에서 2020년 부터 2022년 까지 3년 동안 수행하였다. 사료 피와 강아지풀은 파종량이 증가함에 따라 증가하는 경향을 보였으며 사료 피는 40 kg ha^-1 처리에서, 강아지풀은 60 kg ha^-1 처리에서 최대 수량을 보였다. 그러나 바랭이는 4-16 kg ha^-1 처리에서는 비슷한 수량을 보였으며 60 kg ha^-1 처리에서 최대 수량을 보였다. 그리고 건물수량은 사료 피(9,681~11,092 kg ha^-1) > 바랭이(8,311~9,023 kg ha^-1) > 강아지풀(3,145~4,749 kg ha^-1) 순으로 나타났다. 하계자생작물인 사료 피, 강아지풀, 바랭이의 파종량에 따른 단백질함량은 바랭이 > 사료 피 > 강아지풀 순으로 ADF와 NDF 함량은 사료 피 > 바랭이 > 강아지풀 나타났으며 통계적인 차이는 보이지 않았다. 이상의 결과에서 제시한 바와 같이 논을 이용한 이모작 작부체계에서 안정적으로 조사료를 생산하기 위해서는 자생하계사료작물 도입은 매우 중요할 것으로 판단된다.