• Korean Journal of Soil Science and Fertilizer
• /
• v.30 no.4
• /
• pp.309-313
• /
• 1997

Field experiments were conducted on Jeonbug series (Fine silty, mesic family of Aeric Fluventic Haplaquepts), to study the effect of split application of N fertilizer in combination with rice straw on N use efficiency of dry-soil-direct seeded paddy rice. Treatments involved conventional application of N (in three splits; 40% at planting, 30% at five leaf stage and at heading stage) without rice straw, all basal application of N with straw application (5000 kg/ha), N application in two splits (70% at planting and 30% at heading stage) with rice straw application and N application in three splits (40% at planting, 30% at five leaf stage, 30% at heading stage) with application of rice straw. There was Zero N plot too for the estimation of N use efficiency. Seeding was done on dry soil and the filed was flooded 32 days after seeding. The fertilizer application rates were 160, 70, and 80 kg/ha of N, $P_2O_5$ and $K_2O$, respectively. The experiment was conducted for two years, in the same filed. The apparent use efficiency of fertilizer N by rice tended to be higher under the application of rice straw when N was applied in three splits. This, however, did not increase the yield of rice significantly. Even under the application of rice straw, the apparent N use efficiency was lower when N fertilizer was applied in one dose at the planting and in two splits. The lower N use efficiency in these cases, did not yield of rice significantly. The periodical analysis of mineral N in the soil suggested that higher mineral N in the soil at the early stages was responsible for the lower apparent N use efficiency.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.32 no.1
• /
• pp.57-64
• /
• 2000

As a method to reduce the sue of agricultural chemicals mulching with thin plastic films has been commonly practised for many years. Although use of plastic films for mulching is very effective in preventing herb growth it is almost impossible to remove all of the plastic films from the agricultural lands and the remaining films eventually contaminate the soils. Therefore, it is very imperative to develop a mulching material that decomposes completely to prevent soil pollution problems and to enhance the competitive edge of domestic agriculture. In this paper the possibilities of using strength resins for improving strength properties of mulch papers made from old corrugated containers were examined. Also mulch papers have been produced and applied for practical farming in upland as well as paddy field. Result showed that the usage of 0.7% of wet strength additives was effective for wet and dry strength of mulch paper. Changes of various process parameters including freeness, cationic demand, one pass retention, nitrogen content, etc. that occurred during trial production of mulch paper have been examined and discussed . It was found that paper mulching was very effective for weed control both in upland field and paddy filed.

• Korean Journal of Environment and Ecology
• /
• v.30 no.2
• /
• pp.146-154
• /
• 2016

In this study, understanding the habitats on spot-billed duck that wintering-breed in the korea, which using the GPS-Mobile based Telemtry (WT-200), I tried to take advantage as the basic data of the protection and management of the habitats of the waterbirds of Korea. Study area is Gyeonggi-do Bokhacheon, Chonmichon, Chungcheongnam-do Gokugyochon, Chungcheongbuk-do Byeongcheoncheon, Jeollabuk-do Mangyunggang, which Five rivers and Jeju Island reservoir, I have attached the tracking of the location(WT -200) to the twenty-five spot-billed ducks. among twenty five ducks, twelve ducks moved to overseas countries, the arrival site was China, North Korea, Russia. Moving average distance was 683km, the largest distance was 1,238km. The average northbound starting date was April 26. The average daily movement distance of thirteen ducks remaining in the domestic country is $1.0{\pm}0.89km$, maximum travel distance was 23.8km. The average daily movement distance of wintering prior to average going north dating is a 0.9km, is the largest 14.6km, the breeding season is an average 1.3km, maximum was 14.4km. Spot-billed duck used the rivers in domestic country most frequently, following was rice field, a filed, reservoir. It used the river most frequently during the wintering period, in the breeding season it used paddy paddies most frequently. While wintering, during the day and night's utilization rate was the highest in the river, but utilization rate was incleased on filed, paddy filed at night. During breeding season, daytime and night's utilization rate was the highest but, utilization rate was increased on river and utilization rate was decreased on river. In accordance with time change, spot-billed duck showed different tendency in paddy fields, and they utilized the filed adjacent to rivers mostly.

• Korean Journal of Environment and Ecology
• /
• v.13 no.3
• /
• pp.261-270
• /
• 1999

낙산복원사업 대상지의 생태계 회복을 위한 계획수립의 기초자료로 사용하기 위하여 부지 내 식생조사를 통해 자연환경을 평가하였다 현존식생도 녹지자연도 및 Hemeroby 등급을 통해 자연성을 평가한 결과 많은 면적이 산림으로서의 기능을 상실한 인공화된 지역이었다. 식생이 존재하는 지역 중 산림의 형태를 유지한 지역은 아까시나무군락을 유지하고 있었고 기타 지역은 휴경지, 논.밭 잡초군락이며 동시에 ruderal 식물군락으로 판명되었다. 성과주변에 식재한 수목은 총 67종 1,243개체였으며 그중 자생종이 27종(40.3%) 544개체(43.8%)였고 도입종과 귀화종 재배종이 각각 17%, 8.8%, 15.4%로 나타났다. 생활형 분석에서는 1,2년생 초본식물이 47%를 차지하였고 귀화율은 24.1%로 나타나 매우 불안정하고 교란된 환경인 것으로 판단되었다.

• Current Research on Agriculture and Life Sciences
• /
• v.15
• /
• pp.7-16
• /
• 1997

The effects of liming and inoculation of nodule bacteria on the growth and yield of soybeans in the 1st and 3rd year paddy-upland rotated paddy fields was investigated. Compared with the 1st rotated field, the degree of nodulation was much higher in the 3rd rotated one with greater difference at flowering stage than at the early stage of soybean growth. At the same time, greater difference in the degree of nodulation was also recognized between soybean varieties. In the 3rd year rotated field, a great deal of nodulation effect was recognized in the no-limed field but not in the limed one. The growth of soybean was not much affected by liming and nodulation at early stage but it was much increased by liming at flowering stage, especially in Williams 79, indeterminate type variety. Most of yield components and yield of soybean at maturity was much increased by liming with greater in Williams 79 than in Namhaekong. Nodulation effect on the yield components and yield was great in the no-limed filed but not in the limed one for both varieties. The yield and yield components of soybean, without no relation with liming and nodulation, was much great in the 3rd year rotated paddy fields than in the 1st year one, which was inferred that the more rotated fields the more yield and better growth of soybeans could be possible in the paddy-upland rotatonal soybean croppings.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.7
• /
• pp.480-487
• /
• 2012

The field study was carried out to investigate runoff characteristics of non-point source (NPS) by cultivation activity in river district. Two sites were selected mainly as G region (paddy field, green house), located in Kwangju, Gyeonggi Province, and S region (ordinary field), located in Namyangju, Gyeonggi Province, those belong to Paldang reservoir watershed. The paddy field with water storage capacity showed a slow increase in runoff as rainfall intensity increases. Meanwhile, both green house and ordinary filed revealed a rapid increase. The average BOD runoff concentration of paddy field, green house, and ordinary field was 2.0 mg/L, 2.8 mg/L, 7.9 mg/L, respectively. It indicates that ordinary field shows the highest value in BOD, SS, T-N, and T-P concentration due to the soil loss during rainfall. As a result of runoff load estimation according to the field, a T-N runoff load of paddy field was 1,793.9 kg/year, higher than that of ordinary field. It was estimated that a SS runoff load of ordinary field was 69,704 kg/year and accounts for more than 70% of overall runoff load.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.14 no.2
• /
• pp.2634-2648
• /
• 1972

The aim of this Study is to bring Light on the effect of irrigation water temperature to the growth and harvest of Paddy rice in Various water Sources. 1. This research was completed in the writer's home nursery garden Located in Chungyoung-Ri, Hoeng sung-Myun, Hoengusung-Konn, Kangwan-Do. 2. The variety of Paddy rice was the IR667. 3. Practice was done by the treatment I .e river water, reservoir, tube well cold and tuke well warm with 3 riplications each. 4. The Paddy was transplanted in a pot 0.9 meter height and 1 meter Square without hottom filled with paddy soil to a planting depth 0.5 meter. The pot was laid underground and Covered with a film of polyethylene to keep of the rain. 5. The method of Cultivation was that used by the Filed Crops Experiment Station of the Office of Rural Development. 6. Atmospheric temperature was recorded every day of the growing period. The precipitation and Sun light was quoted by the KF-46 of Hoengsung. 7. The Soils in the test plots was relatively fortile, being Similar to ordinary paddy soils. 8. The charactor of irrigation water of surface and underground was both normal. 9. During the period of growth the average temperature of the underground water as $14.2^{\circ}C$ and that of the Surface was $24.1^{\circ}$. 10. The most useful water for the rice growing was that of river and reservoir while underground water was found to be generally injurious to the paddy growth because of low temperature. 11. In the case of underground water, there proved to be such harmful effects as reduction of culm length, rate of mature grain, panicle Length and grain weight and delay of tillering time, and heading time. Reading Therefore the writer conduded that the harvest of rice irrigated with underground water Showed a reduction of 15.8% compered with the rice irrigated by surface water.

• Journal of Biosystems Engineering
• /
• v.29 no.3
• /
• pp.267-274
• /
• 2004

Using geo-statistical method, yield data of different fields were analyzed to examine their field variability according to examining year, analysis method. Semivariogram and Kriged maps of geo-statistical analysis were used to examine their spatial dependence within a filed. The results obtained were as follows. 1) Descriptive statistical results of the yield showed that the yield and the difference of yield ranged from 100 to 946kg/10a and from 272 to 653kg/10a, respectively within a field. The coefficient of variation also ranged from 5.9 to 22.4 %. 2) More than 90% of yield data were placed between 350 to 850kg/10a. e results indicated that the gram mass flow sensor should have the measuring range from 0.34 to 0.82kg/s considering the yields when 4 rows head-feeding combine with 0.8 m/s of working speed was utilized. 3) A high spatial dependence was found within paddy field. The Q values ranged from 0.20 to 0.97, and the range of spatial dependence was from 6.9 to 53.3m. From this result, the rational sampling interval for yield investigation was estimated 6.9m. 4) Yields within a field between observation years showed considerable variability even if the field was evenly cultivated and managed. To apply precision agriculture in a paddy field, the field test should be continued to build a solid data-base including meteorological data, blight damage and insect damage.

• Journal of Biosystems Engineering
• /
• v.3 no.1
• /
• pp.47-63
• /
• 1978

This study was conducted to obtain a basic information necessary to assess present rice milling technology in Korea The profiles for milling plants was analyzed by survey work.For the private custom-work mills, which process about 80 percent of domestic rice consumption ,their actual milling test for the identical samples as used for filed mills was conducted. Two rice varieties Japonica and Tongil-type were associated with the experiments. The results are summarized as follows: 1. Analyses for private custom-work mills showed their general aspects as; about 91 percent of the mills belonged to an individual owner ship ; more than 93 percent of the mills was established earlier than 1950 ; about 80 percent of the mills was powered with electric motor; mills having less than two employees were about 75 percent; about 45 percent of the mills provided for warehouse in storing customers cereal grains. 2. The polishers installed in 1,255mills within the surveyed area (7 counties) have been supplied by 44 different domestic manufacturers ;in but about 60 percent of which was supplied by 6major manufacturers. The polishers could be classified into two categories in terms of principles of their polishing actions ;jet-pearler and friction types. About 51 percent of the mills was equipped with the former which has been recognized as giving greater milling recovery than the friction types. 3. Reason for owners of private mills to supplement new machines was due mainly to pgrading their mills to meet the requirements that established by the Government. However, about 60 percent of the mill owners intended to replace with new pearler by their own needs to meet with new high yielding varieties. 4. Processing systems of each previate rice mills surveyed could be classified into three categories, depending upon whether the systems posessed such components as precleaner and paddy separator or not. Only 36.7 percent of mills was installed with both precleanr ad paddy seperrator, 5.0 percent of mills did have neither percleaner nor paddy seperator, and rest of them equipped only one of the two. Hence,it is needed for about 63% of rice miils to be supplemented with these basic facilities to meet with the requirements for the standaized system. 5. Actual milling capacity measured at each field rice mills was shown a wide variation, having range from about 190 to 1,210 kg/hr. The percentages of mills classified according to daily milling capacity based on this hourly capacity were 24.3% for the capacity less than 3 M/T a day; 20.0% for 3-4 M/T; 15.6% for 4-5 M/T; 6.7% for 5-6 M/T; 22.3% for 6-7 M/T; and 11.0% for more than 7 M/T a day. 6. Actual amount of rice processed was about 310 M/T a year in average. About 42% of total milled rice was processed during October to Decembear, which formed a peak demand period for rice mills. The amount of rice milled during January to May was relatively small, but it had still a large amount compared to that during June to September. 7. Utilization rate of milling facility, i. e., percentage of the actual amount of milled rice to the capacity of rice mills, was about 18% on the year round average, about 41% in the peak demand season, and about 10% during June to September. Average number of operating days for mills surveyed was about 250 days a year, and about 21 days a month. 8. Moisture contents of paddy at the time of field mill tests were ranged 14.5% to 19.5% for both Japonica and Tong-i] varieties, majority of paddy grains having moisture level much higher than 1530. To aviod potential reduction of milling recovery while milling and deterioration of milled rice while storage due to these high grain mJisture contents, it may be very important for farmers holding rice to dry by an artificial drying method. 9. Milling recovery of JapJnica varieties in rice mills was 75.0% in average and it was widely ranged from 69.0% to 78.0 % according to mills. Potential increase in milJing recovery of Japonica variety with improvement of mill facilities was estimated to about 1.9%. On the other hand, milling recovery of Tong-il varieties in the field mill tests was 69.8% in average and it ranged from 62% to 77 %, which is much wider than that of Japonica varieties. It is noticed that the average milling recovery of Tong-il variety of 69.8% was much less than that of the Japonica-type. It was estimated th3.t up to about 5.0% of milling recovery for Tong-il variety could be improved by improving the present lo'.ver graded milling technology. 10. Head rice recoveries, as a factor of representing the quality of commercial goods, of Japonica and Tong-il varieties were 65.9% and 53.8% in average, and they were widely ranged from 52% to 73% and from 44% to 65% , respectively. It was assessed that head rice recovery of Japonica varieties can be improved up 3.3% and that of Tong-il varieties by 7.0% by improving mill components and systems.

• Journal of Biosystems Engineering
• /
• v.3 no.2
• /
• pp.88-99
• /
• 1978

In this study, rice harvesting systems suitable to Korean situations and the optimum timing of these systems were determined, respectively, based on experimentally determined factors such as filed yield and the milling quantity and quality measured at various levels of the grain moisture content at harvest. Rice varieties used for the experiment were the AKIBARE (Japonica-type) and the SUWEON 251 (high yielding TONGIL sister-line variety), The harvesting systems studied by the experimental work of this study were traditional system with both the wet material and dry-material threshing system by use of binder with both the dry-material and wet-material threshings, and system by use of combine. Grain samples were taken from final products of the paddy rice harvested from the experiment a fields for each system to measure the recovery rates of the milled rice. The results may be summarized as follows; 1. The milling recovery rate of the AKIBARE variety had highest value within the range of the grain moisture at harvest, showing from 21 to 26 percent. The head-rice recovery for the same variety was a little greater in the wet-material threshing than in the dry-material threshing , higher values of which , were 20 to 25 percent , seen within the range of grain moisture at harvest regardless of the harvesting systems tested. 2. The milling recovery of the SUWEON 251 , when tested for different harvesting systems and harvesting grain moisture, did not show a statistically significant different. In contrast , head-rice recovery for the systems operated by the wet-material threshing was much greater than that by the -material threshing. The difference of the recoveries between these systems range from 2.6 to 4.7 percent. 3. An assessment of the optimum period of -harvest timing for each of the harve\ulcornersting systems tested were made bJ.sed on (a) the maximum total milled-rise yield and (b) the percentage reduction in the total milled-rice yield due to untimely harvest operations. The optimum period determined are: 23-19% for the ATD, AC, STD, SBW, STW systems, 25-21% for the ATW ani ABW systems, and 27-18% for the ABD, SBD, and SC systems, respectively.