• 한국농공학회지
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• 제44권7호
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• pp.53-63
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• 2002

Runoff, sediments and nutrient losses were studied under different patterns of paddy field management: (1) fall and spring plowing (Plowing)i (2) fall plowing for half of plot and spring plowing (Semi-plowing); (3) no-till for fall and spring plowing (Un-plowing) during the non-cropping period in the southern Korea for two years. The runoff amount and initial abstract were significantly affected by plowing practices. Un-plowing plot showed the highest runoff amount among treatments. The concentrations of sediment from Plowing plot were much higher than those from Un-plowing plot, especially after (all plowing. Sediment losses from Plowing plot were 25% more than those from Un-plowing plot. There was significant difference in nutrient losses via runoff water and sediment according to plowing practice. Two-year average of losses of N from paddy field during non-cropping period were 9.42 kg ha$\^$-1/, 8.17kg ha$\^$-1/, and 7.76 kg ha$\^$-l/ for Un-plowing, Semi-plowing, and Plowing plot, respectively, while losses of P were 0.64 kg ha$\^$-1/, 0.58 kg ha$\^$-1/, and 0.58 kg ha$\^$-1/ for each tillage system. Losses of total-N, ammonia-N, nitrate-N, Total-P from Un-plowing plot was larger than those from Plowing and Semi-plowing plots during study period.

• Journal of Biosystems Engineering
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• 제29권3호
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• pp.207-216
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• 2004

This study was intended to investigate the characteristics of ride vibrations transmitted to tractor operator during rotary tillage and plowing operations. Seat accelerations of a 41 ps diesel tractor in rotary tillage and plowing were measured and evaluated as specified in the ISO 2631-1. Effects of working speed and tilling depth on ride vibration were investigated. The level of ride vibration was also evaluated in terms of health guidance caution zones. Some of the results of the study are as follows: 1. The level of ride vibration in plowing was about 4.3 times greater than in rotary tillage. 2. The effect of working speed in rotary tillage differs depending upon the tillage depth. The level of ride vibration was increased with the speed, but it decreased over a certain tillage depth. Fore and aft vibration was 2.2-2.7 times severer than horizontal and vertical vibrations. Dominant frequency band was 1-3.15 ㎐ in fore and aft, 1-3.15㎐ and 16-25㎐ in horizontal, and 16-25㎐ in vertical directions. 3. Plowing reduced the ride vibration by 42.8-50.2%. But its positive effect decreased as the plowing speed increased. In plowing operation, ride vibration was similar degrees in fore and aft, horizontal and vertical directions. The dominant frequency band in plowing operation was 1-2.5㎐ in fore and aft, 1-2.5㎐ in horizontal, and 1-8㎐ in vertical directions. 4. On a basis of daily work hours of 4, total level of ride vibrations in plowing operation is likely to be harmful to operator's health.

• 한국연초학회지
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• 제1권2호
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• pp.111-119
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• 1979

심경과 多肥栽培가 버어리種 담배의 收量 및 品質에 미치는 영향을 구명하고자 耕土깊이를 10,20,30cm로 하고 施肥水準을 標準施肥(138kg/10a), 20%增肥, 40%增肥로 하여 3년간(1976-1978) 實驗한 결과 收量 및 品質 공히 심경 다비할수록 증가하여 수량은 耕土깊이 30cm 구에서 5%, 40%增肥區에서 13%가 증가하였으며 품질은 심경과 다비로 각각 2%씩 증가하였다.

• Journal of Biosystems Engineering
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• 제24권3호
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• pp.195-208
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• 1999

A computer simulation was carried out to investigate draft characteristics of Korean paddy field for obtaining the basic reference to the selection of optimum moldboard type suitable for Korean paddy field conditions. Cylindrical, cylindroidal, semihelical moldboard plows, and one type of oriental Janggi were used for simulation. A series of soil bin experiments was conducted to compare the experimental results with the predicted drafts from computer simulation using the cylindroidal moldboard plow. The computer model predicted draft force with 1~12% error at 12~16cm plowing depth which is the most conventional plowing depth in the rural area in Korea. Thus, the computer model was considered to be good enough for simulation. Due to the different plowing width of experimental plows, specific draft was selected for comparison by computer simulations. Specific draft of cylindrical moldboard plow was ranged from 3 to 6 N/$\textrm{cm}^2$ according to the soil conditions, plowing speed and plowing depth, 2.5~3.0 N/$\textrm{cm}^2$ for semihelical moldboard plow.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2001년도 학술발표회 발표논문집
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• pp.484-487
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• 2001

Runoff, sediments and nutrient losses were studied under different patterns of paddy field management: (1) fall and spring plowing (PL); (2) fall plowing for half of plot and spring plowing (SPL); (3) no-till for fall and spring plowing (NPL) during the non-cropping period in the southern Korea. Sediment losses from PL plot were 25% more than those from NPL plot. There was significant difference in nutrient losses via runoff water and sediment according to plowing practice (P < 0.01). Losses of total-N, ammonia-N, nitrate-N, total-P from NPL plot were larger than PL and SPL plots during study period. Sediment and total-P losses from SPL plot were close to those of PL plot.

• Journal of Biosystems Engineering
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• 제31권3호
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• pp.188-193
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• 2006

Elevation differences within a paddy field relate strongly to plant health, crop homogeneity, and pest control. For precision agriculture (PA), the elevation within a field should be precisely controlled. We analyzed variation in elevation within a rice paddy field over one crop cycle. The study took place in a rectangular plot (100 m x 30 m). Elevations within the a plots was measured by a laser-equipped surveying instrument, that could determine elevations to precisions of I mm. The test field was divided into grids with 30 squares; elevation was measured at the center of each 5 x 10-m grid square. This study measured elevation during nine observation periods from pre-plowing to post-harvest. Descriptive statistics showed the highest elevations after plowing due to soil disturbance. One-way analysis of variance (ANOVA) revealed significant elevation differences before and after plowing and transplanting, although elevations were similar over the period of crop growth. Comparison of pre-plowing and post-harvest data showed differences in elevations, indicating that elevation changes occurred during plowing, rice transplanting, plant growth, and harvesting. In summary, the above statistical analysis indicated that elevation changes occurred due to plowing but not during the plant growth season or due to harvesting.

• 한국작물학회지
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• 제1권1호
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• pp.26-31
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• 1963

1. 본시험은 심경, 밀식, 다시의 3요인으로 된 36조합중 최고의 증수를 기할 수 있는 합리적인 조합을 발견하려는데 목적이 있다. 2. 수량구성요소인 평당수수와 평당입수의 비교에서는 표준시비구에서 심경 15cm 400주구, 2배시비구에서 30cm 300주구가, 그리고 3배시비구에서는 30cm 300주구와 45cm 400주구가 큰 값을 보였다. 3. 현미중에서 볼 때 각요인별 분산비는 시비량, 경운심도, 평당수수의 순이고 모두 유의성을 보였다. 요인상호간 교호작용에서는 심도x비료, 심도x밀도, 비료x밀도의 순이었으며 모두 유의성을 나타냈다. 3요인으로 된 36조합중 30cm의 심경작토에 200∼300주의 밀식을 하고 2배의 시비를 한 구가 최고의 수량을 보임으로써 적합조합으로 인정되었다. 4. 본시험은 충북청주에 위치한 식양토의 포장에서 행하여진 것이다.

• 한국농공학회지
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• 제12권3호
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• pp.2019-2028
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• 1970

1. 트랙터에 의(依)한 효율적(效率的) 경기방법(耕起方法)을 실험(實驗) 고찰(考察)하여 다음과 같은 결과(結果)를 얻었다. 가. 포장내측경기(圃場內側耕起)에 있어서 선회소요시간(旋回所要時間)을 최소(最少)하는 효율적(效率的) 선회법(旋回法)은 선회간격(旋回間隔)이 zr(r=최소선회반경(最少旋回半徑))보다 작을때는 Q 자형(字型), 클때는 U 자형(字型)이다. 나. 포장내측경기(圃場內側耕起)의 단위선회구(單位旋回區) 건(巾) w는 2.5r 시(時) 가장 효율적(效率的)이다. 다. 포장주변부(圃場周邊部) 경기(耕起)에 있어서는 W>-0.0345L + 35.84 시(時)는 혼합경법(混合耕法)이 능률적(能率的)이고 W<-0.0345 + 35.84 시(時)는 반접속경법(半接續耕法)이 능률적(能率的)이다. 라. 포장주변부(圃場周邊部)의 건(巾)l는 내측경기시(內側 耕起時)와 주변경기시(周邊耕起時)에 있어서 모두 적을수록 효과적임으로 최소치(最少値)인 2r가 가장 적합(適合)하다. 2. 트랙터에 의(依)한 단위포장(單位圃場)과 경기능률(耕起能率)과의 관계(關係)를 고찰(考察)하여 다음과 같은 결과(結果)를 얻었다. 가. 종횡비(縱橫比)$\frac{L}{W}$ 및 면적(面積) A가 크면 일반적(一般的)으로 경기능률(耕起能率)은 증가(增加)한다. 나. 경기능률(耕起能率)의 증가율(增加率)은 종횡비(縱橫比) 및 면적(面積)이 크면 클수록 증가율(增加率)이 점차적으로 감소(減少)한다. 다. $\frac{L}{W}-T$ 곡선(曲線)에서 $\frac{L}{W}$에 대(對)한 T의 변화(變化)가 큰 범위(範圍)는 대략(大略) 20a에서 6, 30a에서 5, 50a에서 4, 80a에서 3, 100a에서 2.5 이내(以內)이다. 라. T-A 곡선(曲線)의 변화율(變化率)은 $\frac{L}{W}$의 영향(影響)을 받으나 대략(大略) $T=A^{-\frac{2}{3}}$ 곡선(曲線)의 변화율(變化率)과 같다. 마. 종횡비(縱橫比)가 3이상(以上)일때는 면적(面積)의 크기에 상관(相關)없이 경기능률(耕起能率)에 미치는 10a 면적증가(面積增加)의 효과는 약(約) 5 정도(程度)의 종횡비(縱橫比) 증가효과와 같다. 바. 종횡비(縱橫比)가 $2{\sim}3$일때는 면적(面積)의 크기에 상관(相關)없이 경기능률(耕起能率)에 미치는 10a 면적증가(面積增加)의 효과는 약(約) $4{\sim}2$ 정도(程度)의 종횡비(縱橫比) 증가효과와 같으면 이는 종횡비(縱橫比)가 적을수록, 면적(面積)이 클수록 차차(次次) 감소(減少)한다.

• Journal of Ecology and Environment
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• 제33권2호
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• pp.149-155
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• 2010

This study was conducted to investigate the feeding efficiency of the cattle egret (Bubulcus ibis) and the intermediate egret (Ardea intermedia) in relation to the stage of rice culture during two breeding seasons, 2006 and 2007, in Asan city, Chungcheongnam-do, South Korea. Cattle egrets caught mainly small invertebrate prey (insects and spiders, 98.4%) during all stages of rice cultivation, and had a higher prey capture rate in the plowing stage (14.98 prey/min) than in other stages (2.82-3.51 prey/min). Therefore, the biomass intake rate of cattle egrets was highest in the plowing stage. The intermediate egret captured both loaches (43.4%) and small invertebrates (50.6%). The prey capture rates of intermediate egrets increased gradually from the flooding stage (0.38 prey/min) to the planting stage (1.09 prey/min), and decreased in the growing stage (1.04 prey/min). However, intermediate egrets had the highest biomass intake rates in the plowing stage because more loaches were caught in the plowing stage (0.54 loaches/min) than other stages (0.23-0.36 loaches/min). Consequently, both intermediate egrets and cattle egrets had high energy intakes in the plowing stage and rice fields provided an important feeding habitat for both species.

• Journal of Biosystems Engineering
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• 제35권1호
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• pp.10-14
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• 2010

Biodiesel of 20% (BD20) and 100% (BD100), alterative fuels for tractor, were tested for its power and competitiveness in the various farm operations including plowing and rotary tilling in the paddy fields. No troubles such as engine ignition or abrupt stopping were monitored during the works of plowing, rotary tilling and travelling on the road. According to the tractor PTO test in accordance with OECD tractor PTO test codes, no significant PTO output difference was found between the three fuels. However, fuel consumption rates were different between the biodiesels and diesel fuel in the paddy works, where as biodiesel percentage increased more fuels were spent than the diesel fuel. The reason for this phenomenon seems came from density difference of the three fuels. Maximum fuel consumption difference occurred between BD100 and diesel fuel was about 10% in the plowing. More energy was spent on the rotary tilling operations than the plowing, where 35~40 % more fuel needed on rotary tilling than plowing. Of the exhaust gases, more $CO_2$ was discharged from diesel fuel than biodiesels, but more NOx from biodiesels and CO was hard to determine which fuel produce more amount.