• 한국농공학회지
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• 제43권5호
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• pp.153-162
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• 2001

A study was carried out to investigate the water balance and losses of nutrients at a paddy plot located at the southern Korea. The observed amount of precipitation, irrigation, runoff, evapotranspiration and percolation for the experimental paddy plot during cropping period were 1,030, 566, 701, 551. and 310 mm for 1999 and 1.214, 413, 710, 682, and 234 mm for 2000 year, respectively. The measured input quantities of N and P into the paddy field during cropping period were 122 to 140 kg N $ha^-1$ and 29 to 30 kg $P_2O_5$ kg $ha^-1$ by chemical fertilizer, 20 to 28 kg N $ha^-1$ and 0.35 to 0.36 kg P $ha^-1$ by precipitation, and 26 to 35 kg N $ha^-1$ and 0.57 to 0.72 kg P$ha^-1$ by irrigation water. respectively. The output amounts of N and P from paddy field were measured as follows. They were 48 to 52 kg N $ha^-1$ and 1.1 to 1.6 kg P $ha^-1$by runoff water, and 9 to 12 kg N $ha^-1$ and 0.04 to 0.05 kg $ha^-1$ by percolation water. When the runoff losses of nutrients were compared to applied chemical fertilizer. it was found that 34.3 % to 42.6 % of nitrogen lost via runoff while runoff losses of phosphorus account for 3.8 % to 5.3 % of the total applied amount. When the ratio was calculated between nutrients losses by percolation water and the applied of chemical fertilizer, two year results showed 6.4 % to 9.8 % for the nitrogen and 0.1% to 0.2% phosphorus, respectively.

• Journal of Biosystems Engineering
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• 제7권2호
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• pp.36-44
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• 1983

Farm population was rapidly decreasing due to shift of the people from farm sector to the non-farm sector caused by the economic growth of the country. Especially, a great shortage of farm labor in busy farming period in June and October is becoming a serious problem in maintaining or promoting land productivity. The peak of labor requirement in summer is caused by rice transplanting and barley harvesting. In order to reduce the restrictions imposed on farm management by the concurrence of labor requirement and the lack of labor, the experimental study for mechanization of barley harvesting has been carried out in the fields. 1. The machines for barley harvesting were knap-sack type reapers, windrow reaper (power tiller attachment), binder and combine. The order of higher efficiency of machine for barley harvesting was combine, binder, windrow reaper (WR), knapsack type reaper 1(KSTR1), and knap sack type reaper 2(KSTR2; mist and duster attachment). 2. The ratio of grain loss for the manual, binder, and combine plot was about four percent of total field yield. 3. The total yield of barley in 35 days and 40 days harvesting after heading were 514 kg and 507kg per 10 ares respectively. The yield of 35 days-plot was higher than other experimental plots. 4. The lowest yield was recorded in 30 days-plot due to the large quantity of immatured grains and having lighter 1000-grain weight. The ratio of immatured grains was 2.66 percent and 1000-grain weight was 29.4 grams. 5. The total harvesting cost of the windrow reaper was 10,178 won per 10 ares. It was the lowest value compared to other machines. The next were combine, binder, KSTR1, KSTR2, and manual in sequence. As a result, the optimum time of barley harvesting for mechanization was 35-40 days after heading. Combine, binder, and windrow reaper were recommended as the suitable machines for barley harvesting in the work efficiency. However, in total harvesting cost, the windrow reaper was the most promising machine for barley harvesting.

• 한국작물학회지
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• 제52권2호
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• pp.183-197
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• 2007

Field trial was conducted at the Research Farm of the Katsina State Agricultural and Rural Development Authority during the farming season of 2004 with a view to evaluate/determine the efficacy of some selected plant-derived biopesticides against the insect pests of cowpea as well as their effect on yield. The variety of the cowpea used was IT86D-719 and the plant derived biopesticides evaluated during the trial were chilli pepper, garlic, ginger, neem, sweetsop and tobacco. The experimental field was ploughed, harrowed and thereafter ridged before the commencement of the 2004 planting season. A total of twenty one (21) experimental plots were demarcated and arranged into seven treatment plots. The size of each plot was $5m{\times}4m$ while interspaces between adjacent plot and blocks were 1m and 2m, respectively. Results of the experiments showed that all the plant-derived biopesticide treatments were significantly (p>0.05) better than control treatment. The order of effectiveness of the treatments was tobacco (80-90%), sweetsop (75-85%), garlic (70-80), neem (72-78%), chilli pepper (60-70%) and ginger (30-50%). Furthermore, yield result corresponded positively with the effectiveness of the treatments. Results of the present finding suggest the use of tobacco, sweetsop and garlic as promising biopesticides in the control of cowpea insect pests.

• Journal of Ecology and Environment
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• 제35권4호
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• pp.343-349
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• 2012

The use of growth medium is often recommended milkweed seedlings to grow and develop after emergence, and it is affected by growth medium and local habitat conditions. The effects of growth medium and partial shade on early growth of milkweed under drought stress (Calotropis procera L.) were studied in a field experiment. A split-split plot experimental design with three replications was carried out in the nursery. The main treatment plot was divided into two levels of shade; (no shading and partial shading). Sub treatment plot1 included growth medium at four levels (G1 = clay [suitable for milkweed growth], G2 = clay + sand, G3 = clay + perlite, G4 = clay + perlite + sand) and sub treatment plot2 included drought (irrigation intervals) at six levels (D1 = 2 [control], D2 = 4, D3 = 6, D4 = 8, D5 = 10, and D6 = 12 days per for three month). The results showed that drought stress significantly decreased emergence percentage, shoot length, shoot dry weight (SDW1), root dry weight (RDW), seedling dry weight (SDW2) and vigor index (VI). The use of growth medium increased all seedling characteristics. The G3 (clay + perlite) growth medium showed the highest performance, especially in terms of emergence percentage and seedling dry weight. Partial shade improved shoot length, shoot dry weight, and vigor index. Our results showed that the best treatment for high-vigor milkweed seedlings under drought stress was G3 (clay + perlite) growth medium and partial shade.

• 한국농공학회지
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• 제11권1호
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• pp.1598-1603
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• 1969

본실험(本實驗) 관개방법(灌漑方法)을 합리화(合理化) 시켜서 관개용수(灌漑用水)를 절약(節約)하고 보수력(保水力)을 증대(增大)시키는 동시(同時)에 증수(增收)를 꾀하는 방법(方法)으로서 시험결과(試驗結果)를 요약(要約)하면 다음과 같다. 1. 토양(土壤)의 이화학적성질(理化學的性質)에는 별차이(別差異)가 없었으며 관개수질(灌漑水質) 기타(其他) 기온(氣溫) 강우량등(降雨量等) 모든 값이 각처리구(各處理區)에 모두 동질(同質)이었다. 2. 엽간중(葉稈重)은 각처리구간(各處理區間)에 유의성(有意性)이 없었다. 3. 밑다짐의 두께에 있어서는 9cm 두께구(區)가 다소(多少) 성적(成績)이 좋았으나 경제성(經濟性)으로 보아 3cm구(區)가 가장 적당(適當)한 것으로 생각된다. 4. 수량(收量)에 있어서는 밀집(區)가 우월(優越)하였으나 이것은 다비(多肥)의 효과(效果)가 발효(發效)된 것으로 보며 그내용한(耐用限)이 문제점(問題點)이며 $2{\sim}3$년(年)마다 반복작업(反復作業)을 해야 할것으로 보며 노력(勞力)이 많이 소요(所要) 될 것이다. 5. 금년도(今年度)에는 시험구작성관계(試驗區作成關係)로 인(因)하여 표토(表土)와 심토(心土)가 다소(多少) 이동혼합(移動混合) 되었을 것이므로 완성(完成)한 시험결과(試驗結果)인가 의문(疑問)되나 일주수수(一株穗數)와 일수입수(一穗粒數)의 변화(變化)에는 유의차(有意差)를 보였다. 6. 본시험(本試驗)은 밑다짐한 후(後) 보통재배법(普通栽培法)에 의(依)하여 관개(灌漑)하였는데 $5{\sim}6$일(日) 1회(回)의 관개(灌漑)로서 밑다짐90cm구(區)에서 44.9% 밑다짐6cm 구(區)에서 39.7% 밑다짐 3cm 구(區)에서 36.3%의 용수절약(用水節約)을 보았다. 7. 수량(收量)에 있어서 밀짚(區)가 23.8% 밑다짐 90cm 구(區)에서 20.1% 밑다짐3cm구(區)에서 12%의 증수(增收)를 보았고 비닐 $3cm/m^3$ 구멍구(區)에서 12.5%의 증수(增收)를 보았다. 8. 임실율(稔實率)이 양호(良好)하였으며 도정율(搗精率)이 75%로서 품질(品質)이 향상(向上)되었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.75-75
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• 2022

Traditional agriculture mostly focused on activity in the field, but current agriculture faces problems such as reduction of agricultural inputs, labor shortage and so on. Accordingly, traditional agricultural experiments generally considered the simple treatment effects, but current agricultural experiments need to consider the several and complicate treatment effects. To analyze such several and complicate treatment effects, data collection has the first priority. Remote sensing is a quite effective tool to collect information in agriculture, and recent easier availability of UAVs (Unmanned Aerial Vehicles) enhances the effectiveness. LAI (Leaf Area Index) is one of the most important information for evaluating the condition of crop growth. In this study, we utilized UAV with multispectral camera to evaluate plant-based LAI of sweetcorn in a small-scale field experiment and discussed the feasibility of a new experimental design to analyze the several and complicate treatment effects. The plant-based SR measured by UAV showed the highest correlation coefficient with LAI measured by a canopy analyzer in 2018 and 2019. Application of linear mix model showed that plant-based SR data had higher detection power due to its huge number of data although SR was inferior to evaluate LAI than the canopy analyzer. The distribution of plant-based data also statistically revealed the border effect in treatment plots in the traditional experimental design. These results suggest that remote sensing with UAVs has the advantage even in a small-scale experimental plot and has a possibility to provide a new experimental design if combined with various analytical applications such as plant size, shape, and color.

• 한국대기환경학회지
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• 제7권3호
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• pp.208-218
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• 1991

To compare the resistance of landscape trees by acid rain, simulated acid rain was treated on the seeds of 6 coniferous species (Pinus densiflora, Pinus thunbergii, Pinus koraiensis, Taxus cuspidata, Cedrus deodara, Thuja occidentalis) and 6 broad-leafed species (Ligustrum obtusifolium, Acer Buergerianum, Acer Ginnala, Styrax obassia, Cornus Kousa, Magnolia obovata). The experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agri-Tech Junior College. The seeds of 12 tree species were planted on the nursery soil in the early spring of 1991. The regime of artificial acid rain, in terms of spray frequency per monthly and spray amount at year records. Simulated acid rain (pH 2.0, pH 4.0, pH 5.6 as control) containing sulfuric and nitric acid in the ratio of 3:2 (chemical equivalant basis) diluted ground water, were treated on the experimental plants under condition of cutting off the natural precipitation with vinyl tunnel, during the growing season (April 8 to August 31) in 1991. Seedling establishment, seedling growth and nutrient contents in needles and leaves were measured and compared among the treatment. The results were summerized as follows; 1. In general, coniferous species were more resistant than broad-leafed species in the resistant comparisons of landscape trees by simulated acid rain. But there were resistant tree species to acid rain among the broad-leafed species. 2. Among 6 coniferous species used in this experiment, Pinus densiflora, Pinus koraiensis, Taxus cuspidata, Cedrus deodara and Pinus thunbergii revealed the resistant tree species to acid rain. But Thuja occidentalis was very susceptible to acid rain, because of no germination in pH 2.0 treatment plot of acid rain. 3. Among 6 broad-leafed species used in this study, Magnolia obovata, Styrax obassia and Ligustrum obtusifolium showed relative resistant tree species to acid rain. But Acer Buergerianum, Acer Ginnala and Cornus Kousa were very susceptible to acid rain, because of no germination in pH 2.0 plot of acid rain treatment.

• 한국농공학회논문집
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• 제55권2호
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• pp.29-36
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• 2013

The objective of the research was to describe the effect of straw mat cover and soil amendments on the reduction of runoff and non-point source load from steep sloped highland agricultural fields. Four $5{\times}30$ m plots on sandy loam soil with 28 % slope were prepared. Experimental treatments were bare (control), rice straw mat cover (3,000 kg/ha) (S), PAM (5 kg/ha)+Gypsum (1 ton/ha) (PG) and rice straw mat cover+PAM+Gypsum (SPG). A variety of lettuce was cultivated and runoff was monitored during a growing season in 2011. Natural monitoring was conducted to three times. Runoff rate of S, PG and SPG plots were significantly lower than those of control plot. Especially, the runoff rate is zero in SPG plot at a first rainfall events. The reduction rate of runoff from the S, PG and SPG plots was 30.8 %, 29.0 % and 81.8 % compared to control plots, respectively. The reduction rate of NPS pollution load of S, PG and SPG was ranged of 50~90 %, 30~70 % and 90~100 %, respectively. Yield of lettuce from S, PG and SPG plots was respectively 400 (567 kg/ha), 320 (453 kg/ha) and 760 (1,067 kg/ha) that of compared to control plots greater than that from control plots (140 kg/ha). We speculated that the experimental treated plots could hold more nutrients and moisture than the control and helped the crop grow healthier. When analyzing the above results, in terms of reduction of runoff and NPS pollution load and crop yields, SPG experimental treatment had the best effect. It was concluded that the use of rice straw mats cover and soil amendments on soil surface could not only reduce the NPS pollution loads in receiving waters but also help increase the crop yield.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.338-338
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• 2017

One of the problems in increasing rice production is getting lines or varieties that have high adaptability so that able to produce maximum production in a variety of environmental conditions. One strategy that can be done to get adaptive varieties is through the improvement of native varieties. This research was conducted in rain fed paddy field, Aceh province, Indonesia from June to September 2014. The texture of the soil was clay-loam with the soil pH ranged from 6.5-6.7. Five potential progenies of rice from crossing between native Indonesian rice with introduced rice varieties consist of C3, C4, S3, S5, S6 were used in this study. Besides that, one national rice variety Ciherang also used as a comparison. The plants were growth in the plot with the size of $2m{\times}1.4m$ with plant distance was $20cm{\times}20cm$. The fertilizers used in this study were Urea, NPK, and KCl. Randomized block design with 6 rice progenies/variety and 3 replications were used in this study. There were 18 experimental units and each experimental unit had 10 samples for the sources of data. The variables that were observed in this study including plant height at harvesting time, number of productive tiller, the percentage of empty grains and filled grain per panicle, weight of filled grains per hill, weight of filled grain per plot and yield potential per hectare. Analyzed were also conducted for the depth of root penetration, dry-root weight, dry-shoot weight, shoot-root weight ratio and its correlation with the weight of filled grain per hill. The research results show that there was significant difference on plant height at harvesting time, number of productive tillers, the percentage of empty grains and filled grain per panicle, weight of filled grains per hill, weight of filled grain per plot and yield potential per ha (p>0.01) among the treatments. In addition, depth root penetration, dry-root weight, dry-shoot weight, shoot-root weight ratio also had significant difference (p>0.01) among the treatment. The highest plant at harvesting time was found in S6, reaching 129.8 cm and the shortest plants was found in C3 reaching 107.5 cm. The largest number of productive tillers and the highest percentage of filled grains per panicle were found in Ciherang reaching 10.5 tillers and 80.7% respectively. Ciherang also had the heaviest weight of filled grains per hill and per plot reaching 21.1 g and 2.18 kg respectively. Whereas, S6 had the lowest number of tillers and the lowest percentage of filled grain per panicle.. The highest yield potential per ha was found in Ciherang reaching 7.79 tons. Among the progenies, S5 had the highest yield potential reaching 5 tons/Ha. The result also showed significant relationship between shoot-root weight ratio with weight of filled grains per hill. The highest value of shoot-root weight ratio (1.57) in Ciherang is thought had closed relationship with its yield potential.

• 한국토양비료학회지
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• 제43권1호
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• pp.25-35
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• 2010

약간 경사가 있고 침식 가능성이 높은 배나무 과수원 포장에서 2가지 종류의 제초제를 처리하여 유거수와 토양침식의 변화를 관찰하였다 : (1)발아 전 처리 제초제 - Glyphosate; (2)발아 후 처리 제초제 - Paraquat. 조사지 포자의 고도는 125 m 경사도는 5.5% ~ 10.2%의 분포를 보였다. 한편 조사기간인 2006년 6월과 2008년 11월 사이의 강우 횟수는 각각 47, 52, 52회로 조사되었다. 정상적인 침투율은 보통 잡초가 모두 제거된 맨땅에서 증가하지만 제초제가 처리된 땅에서는 감소했다. 대조구에서 유거수는 항상 제초제를 처리한 땅과 맨땅에서 보다 더 적었다. 같은 강우강도에서 유거수는 대조구, glyphosate 그리고 paraquat 순으로 증가하였다. 강우의 강도가 센 경우에 유거수 차이는 조사 첫해에 약간 더 높았다. 토양 유실은 연구기간 3년 동안 약간씩 다르나 조립질 토양보다 미세질토양에서 유실이 더 많았다. 하지만 토양유실은 총강우량과 유거수와는 밀접한 연관이 없는 것으로 조사되었다. 동일 강우강도에서 토양침식률은 대조구, glyphosate, paraquat 그리고 glyphosate가 처리된 맨땅 순으로 증가하였다. 상대적으로 30 mm $day^{-1}$보다 낮은 강우량에서 제초제 처리와 상관없이 토양유실에 미치는 영향은 차이가 없었다. 결과적으로 토양침식에서 중요한 요인은 강우강도이다.