• 한국초지조사료학회지
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• 제14권2호
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• pp.69-75
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• 1994

This experiment was canied out to study the effect of cutting frequencies (3, 4 and 5 cuts per year) and mineral nitrogen fertilization on dry matter yields, in order to estimate optimum level of fertilizing mineral nitrogen in orchardgrass(Dacry1is glomerafa L.). The results are as follows: 1. Dry matter yields were the highest in the 1st cut at 3 cutting frequency and in the 2nd cut at 4 and 5 cutting frequencies, and they shared 49.7, 37.0 and 37.0% of annual dry matter yield respectively. 2. When only phosphorus and potassium were applied, annual dry matter yields were between 9.4 and 11.5 tons per ha and the highest yield was observed at 3 cutting frequency. 3. Dry matter yield in relation to fertilization of mineral nitrogen was highly increased when more nitrogen was applied as 360 kg per ha compared to 240 kg per ha at 3 cutting frequency. At 4 and 5 cutting frequencies, increases in dry matter yield, to large extent, were showed at 120 and 150 kg of nitrogen per ha(30 kg Nlcutlha) compared to no application of nitrogen. The efficiencies of mineral nitrogen fertilization (kg DM/kg N) were 28.0, 22.7 and 20.6 kg dry matter yields per nitrogen(kg) respectively). 4. At 4 and 5 cutting frequencies, dry matter yields were reduced when 360 kg and 300 kg of mineral nitrogen per ha(90 kg and 60 kg Nlcutlha) were applied respectively. 5. Particularly at 4 and 5 cutting frequencies of this study, maximum marginal yields reached at 129.9 kg and 148.0 kg of fertilizing mineral nitrogen per ha, and economical borden of mineral nitrogen fertilization were between 222.4 and 250.0 kg and between 244.8 and 276.8 kg respectively. At the same cutting frequencies, the highest dry matter yields were obtained at 365.4 and 433.8 kg of fertilizing mineral nitrogen respectively.

• 한국유기농업학회지
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• 제12권4호
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• pp.411-425
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• 2004

The aim of this experiment was to investigate the effects of applying times and dilution rates of cattle slurry with water on dry matter yields and feed values of orchard grass. Cattle slurry was applied at the rates of average nitrogen fertilizer equivalent to 150kg/ha/year in 3 cutting frequency. Significantly higher dry matter yields than that of no fertilization (7.36 ton DM/ha) were recorded in the application of diluted cattle slurry (10.74~13.54 ton DM/ha) (p<0.05). Especially, this tendency was shown with higher annual dry matter yields at the partitioned dressing times, such as at the applications for 1st and 3rd growth, 2nd and 3rd growth, and 1st, 2nd and 3rd growth respectively. The yields of annual dry matter at fertilizing phosphorus, potassium and nitrogen were higher than no fertilization as 12.42 tons per ha. However, with application of diluted cattle slurry, dry matter yields per year (11.96 ton DM/ha) were significantly higher than those of fertilizing phosphorus and potassium (7.52 ton DM/ha) (p<0.05). The efficiencies of dry matter production with mineral and cattle slurry nitrogen application (kg DM/kg N) were 32.7 and 13.4~26.9kg DM/kg N respectively. Especially, these tendencies were higher in diluted application plots than in no-diluted application plots of cattle slurry. The contents of crude protein (CP, %), neutral detergent Eber (NDF, %), acid detergent fiber (ADF, %), annual yields of CP (kg/ha) and total digestible nutrient (TDNY, kg/ha) of orchardgrass were significantly higher at the application of diluted cattle Slurry than those at non-fertilizer application (p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.261-264
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• 1994

The lactation milk yields of 209 buffaloes and cattle were measured on farms in Taplejung and Dhankuta Districts in East Nepal. This includes local and crossbred buffaloes and cows. The average milk yield (${\pm}\;SD$) of 97 local buffaloes was $833\;{\pm}\;94.6\;kg$ whereas that for 83 local cows was only $455\;{\pm}\;61.5\;kg$. The milk yield of buffaloes decreased with number of calvings, but that for the cows increased. The milk yields of 18 Murrah crossbreds were on average 215 kg higher than the yields of local buffaloes, and the yields of 11 Jersey crossbred cows averaged 247 kg more than the local cows. Lactation length (${\pm}\;SD$) which averaged $326\;{\pm}\;100$ days for the buffaloes and $292\;{\pm}\;98$ days for the cows, was not affected by crossbreeding. The milk yields of the crossbreds were more variable than the local buffaloes and cows. In addition to milk yield the overall productivity of a milking animal depends on calf mortality, age at first calving, calving interval, longevity, food intake, the work performance of male cattle and the meat production of male buffaloes. Among these parameters, the work performance of Jersey crossbred and local male cattle was studied later. However, other factors could not be measured.

• 한국유기농업학회지
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• 제12권2호
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• pp.209-217
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• 2004

The aim of this experiment was to investigate the effects of applying times and dilution rates of cattle slurry on dry matter yields of orchard grass. Cattle slurry was applied at the rates of average mineral nitrogen fertilizer equivalent to 150 kg/ha/year in 3 cutting frequency. Significantly higher dry matter yields than that of no fertilization (3.04 ton DM/ha) were recorded in the application of diluted cattle slurry(5.38~6.25 ton DM/ha) (p<0.05). Especially, this tendency was shown with higher annual dry matter yields at the partitioned dressing times, such as at the applications for 1st and 2nd growth, 1st and 3rd growth, and 1st, 2nd and 3rd growth respectively. The yields of annual dry matter both at fertilizing phosphorus and potassium, and phosphorus, potassium and nitrogen were higher than no fertilization as 5.41 tons and 8.78 tons per ha respectively. However, with application of diluted cattle slurry, dry matter yield par year (5.84 ton DM/ha) was higher than those of fertilizing phosphorus and potassium. The efficiencies of dry matter production with mineral and cattle slurry nitrogen application (kg DM/kg N) were 225 and 15.8~18.7 kg DM/kg N respectively. Especially, these tendencies were higher in diluted application plots than in no-diluted application plots of cattle slurry.

• 한국초지조사료학회지
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• 제20권1호
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• pp.31-40
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• 2000

This study was conducted to investigate the effects of application levels of swine manure fermented with sawdust(SMFS) and degree of the slope on productivity of corn, and nitrogen and organic matter runoff in corn cultivation soil. Main plots were consisted of the degree of slope, such as 0, 5 and 10, and the subplots consisted of application levels of SMFS, such as control, 200kgNha and 400kgNha. Lysimeter was constructed with 0.33m width, 3m length and 0.4m height. Dry matter(DM) yields of corn decreased as the slope increased but there was no significant differences between the degree of the slope. DM yields increased significantly as application levels of SMFS increased (pc0.05). DM yields decreased according to continuous cultivation of corn. Total nitrogen(TN) contents of the whole corn decreased as the slope increased(p<0.05). TN content in SMFS treatments was higher than that of non-SMFS treatment but there was no significantly different between SMFS treatments. TN yields decreased significantly as the slope and the application level of SMFS increased(p<0.05). Nitrogen and organic matter yields in the runoff waters increased as the slope and application levels of SMFS increased. The runoff of nitrogen and organic matter was more affected by the increase of the slope than application levels of SMFS. (Key words : Corn, Runoff, Swine manure, Degree of slope, Lysimeter)

• 한국유기농업학회지
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• 제12권4호
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• pp.437-450
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• 2004

This study was conducted with two objectives ; one was to select the suitable soybean cultivars for cultivation in paddy field and the other was to establish the environment-friendly rotational cropping system of soybean instead of rice in paddy field. In order to evaluate growth adaptation and yields, Eve soybean cultivars were cultivated in Yeoncheon, Keonggi province, with two cultivation methods such as level row and high ridge. Growth of the top plants, such as stem length, number of branches, diameter of stem, were higher in high ridge than in level row, however, the differences among the cultivars were bigger than those between the cultivation methods. Dry weight of top plant was significantly different among the cultivars during whole growth stages, however, it was higher in level row than in high ridge at V5 stage while it became higher in high ridge as growth progressed. Roots were more developed in high ridge than in level row during whole growth stages. T/R ratio in level row was higher than that in high ridge. During whole growth stages, significant differences were observed among the cultivars in growth and yields in each cultivation method and yields of Eunhakong was the highest. In results, number of nodules and T/R ratio at V5 stage, number of pods at R2 stage, and number of seeds and T/R ratio at R5 stage had highly correlated with yields, respectively.

• 한국기후변화학회지
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• 제8권3호
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• pp.187-199
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• 2017

We attempted to assess the impact of climate change on rice yields in Cambodia and to investigate adaptation strategies to climate change including more drastically shifting the planting dates and considering more fertilizer application levels. The potential yields of two wet season rice cultivars (Sen Pidao and Phka Rumduol) under two climate change scenarios in Cambodia were simulated using the CERES-Rice model. Field experiments conducted at the Cambodian Agricultural Research and Development Institute (CARDI), in 2010, 2011, and 2013 and climate variables from the HadGEM3-RA model were collected for this study. Compared with the baseline (1991-2000), yields of Sen Pidao rice will decrease under climate change and yields of Phka Rumduol rice could increase or decrease depending on fertilizer rates and the periods (2040s, 2050s, and 2080s). In general, the variations in the simulated effects of climate change on yields were more sensitive at fertilizer N100-N200 and less sensitive at fertilizer N0-N50. It is likely that forward shifts of planting date from the baseline plating date for the two cultivars in the future can be more benefitted than backward shifts. It is concluded that the CERES-Rice model can be useful to provide efficacious adaptation strategies in Cambodia.

• 한국기후변화학회지
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• 제6권1호
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• pp.21-31
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• 2015

Various crop models have been extensively used for estimation of the crop yields. Compared to the other models, the EPIC model uses a unified approach to simulate more than 100 types of crops. It has been successfully applied in simulating crop yields for various combinations of weather conditions, soil properties, crops, and management schemes in many countries. The objective of this study was to estimate the rice and maize yield in South Korea using the EPIC model. The input datasets for the 30 types in the 11 categories were created for the EPIC model. The EPIC model simulated rice and maize yields. The performance of the EPIC model was evaluated with the goodness-of-fit measures including Root Mean Square Error (RMSE), Relative Error (RE), Nash-Sutcliffe Efficiency Coefficient (NSEC), Mean Absolute Error (MAE), and Pearson Correelation Coefficient (r). The rice yield showed to more high accuracy than maize yield on four type of method without NSEC. Theses results showed that the EPIC model better simulated rice yields than maize yields. The results suggest that the EPIC crop model can be useful to estimate crop yield in South Korea.

• 한국초지조사료학회지
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• 제24권3호
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• pp.193-200
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• 2004

Orchardgrass 및 white clover에서 미량요소 Fe, Mn, Cu 및 Zn의 systematic variation 시비가 목초의 생육, 개화, 수량 및 양분 함량 등에 미치는 영향 등을 구명하였다. 다량요소 양분을 동일량 시비한 조건에서 시험군-1(Fe/Cu), 시험군-2(Mn/Zn), 시험군-3(Fe+Cu/Mn+Zn)의 처리내용은 시험군별 처리양분의 총 시비량($100\%$)을 systematic variation 방법으로 각각 0/100, 25/75, 50/50, 75/25, $100/0\%$ 비율로 나누어 시비처리 하였고, 시험군-4(Fe/Mn/Cu/Zn)에서는 각 기준양분 $70\%$, 기타 양분은 각각 $10\%$(합계 $100\%$) 비율로 시비처리 하였다. 1. 일반적으로 처리별 수량에 미치는 영향은 초종간 큰 차이를 보였으며 white clover는 orchardgrass 보다 더 크게 영향을 받았다. white clover의 처리별 수량변화는 뿌리/근류의 생육 및 개화특성 등과 연관성을 보였다(I보). 2. Fe/Cu 비율시험에서 orchardgrass의 수량은 $100/0\%$ 처리에서, white clover는 75/25 처리에서 다소 높은 수량을 보였다. 또한 white clover의 양호한 생육과 수량은 Cu 비율에 더 크게 영향을 받았고 orchardgrass는 Fe 비율에 더 영향을 받는 경향 이였다. 3. Mn/Zn 비율시험에서 두 초종 공히 높은 Mn 비율에서 양호한 수량을 보였다. 그러나 Mn-결핍조건에서는 white clover가 orchardgrass보다 상대적으로 더 수량감소를 보였다. 이에 비해서 Zn-함량의 변화와 이의 수량에 미치는 영향은 경미하였다. 4. Fe+Cu/Mn+Zn 비율시험에서 orchardgrass는 처리간 수량 차이가 경미하였다. white clover는 orchardgrass에 비해서 처리별 수량차이가 크게 나타났다. 75/25 처리에서 높은 수량을 보였으며 100/0 처리에서는 후반기에 심한 수량감소를 나타냈다. Fe/Mn/Cu/Zn 비율시험에서 white clover는 Cu와 Zn 처리에서 다소 양호한 수량을 보였고 이는 아마도 균형된 Fe/Mn 비율과도 연관된 것으로 보였다.

• 한국경영과학회지
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• 제22권1호
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• pp.51-58
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• 1997

In this paper, we propose a stochastic LP model for determining an optimal input quantity in a single-product multi-stage production system with random yields. Due to the random yields in our model, each stage of the production system can result in defective items, which can be re-processed or scrapped at certain costs. We assume that the random yield at each stage follows an independent discrete empirical distribution. Compared to dynamic programming models that prevail in the literature, our model can easily handle problems of larger sizes.