• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.85-92
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• 2015

The experiment was conducted to evaluate rice growth and yield as affected by different coating and covering materials such as a iron, silicate, iron and silicate mixture of rice seeds in farmer's rice growing field. The tiller number was 36.7 at iron-coated seeds, 32.8 at silicate-covered seeds, 30.3 at iron and silicate mixture coated seeds and 30.2 at untreated control in 44days after seeding. The seedling height was 38.2cm of iron and silicate mixture, 37.7cm of untreated control, 36cm of iron-coated and 35.7cm of silicate covered seeds in 43days after seeding. At 75days after seeding rice tiller number was 153 of iron-coated seeds, 152 of silicate-covered seeds, 147 of untreated seeds and 141 of iron and silicate mixture-coated seeds and also there were different plant height growth of 87.4cm in silicate-covered seeds, 85.7cm in iron and silicate mixture, 85.4cm in untreated control and 83.0cm in iron-coated seeds. The panicle length was of 21.0cm in iron and silicate mixture coated seeds, 20.8cm in silicate covered seeds, 20.7cm in untreated control seeds and 20.6cm in iron-coated seeds. The panicle number was 464 at iron-coated seeds, 404 at untreated control seeds, 427 at silicate-covered seeds and 412 at iron and silicate mixture coated seeds. The spikelet number per m² was of 32,503 in iron-coated seeds, 31,813 in silicate-covered seeds, 29,646 in untreated control, 28,896 in iron and silicate mixture coated seeds. The ripened ratio of rice grain was of 94.5% at iron-coated seeds, 93.9% at iron and silicate mixture coated seeds, 93.6% at silicate covered seeds and 93.2% at untreated control seeds. The rice yield was of 591kg/10a at iron-coated seeds, 580kg/10a at silicate-covered seeds, 571kg/10a at iron and silicate mixture-coated seeds and 539kg/10a at untreated control.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.313-318
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• 2014

The remote monitoring system of water salinity was assessed in Wando reclaimed land lake during a farming season in 2009. Increasing of water salinity in this lake used to bring about salt damage on rice plant occasionally. At the early stage of the rice growing period, rice growth was not damaged due to enough rainfall with more than 120 mm from the mid-May to the first ten days of June. Data collection using on-site water salinity measuring sensors every 2 hours and real-time transmission in system were carried out for the experiment. We compared the transmitted values from the sensor system with water sample values collected and analyzed by a local technical office. Salt concentrations measured by sensor in real-time monitoring system were available data. The regression equation between rainfall and water salinity was presented as (water salinity after rainfall) = $0.621{\times}$(water salinity before rainfall)${\times}exp(-0.0139{\times}rainfall)$, ($r^2=0.579$, p<0.01). It is suggested that the system is useful for stable farming in the area where farmer use water in reclaimed lakes as an irrigation source.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.336-336
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• 2017

High mortality and slow growth of seedling generally occurred in tray due to cold, foggy weather and severe seedling blight. Mechanical transplanting is hampered, farmers having economic loss. A sustainable method for raising mat type seedling is necessary. Experiments were conducted on disease control and seedling growth in dry seasons. Fungicides treated/untreated seeds were sown 120-130g in each tray containing pulverized fine grain loam/sandy loam soils. Seed covered with a thin layer of soil and irrigated. It was polythene covered (PC) for 72h and then every night along with 2/3 sprinkler irrigation (SI) per day. Untreated seedlings infected 53-93%. Pyraclostrobin, Azoxystrobin and Azoxystrobin+Difeconazole treated seeds/sprayed (72h) seedlings had no disease. Seedling height was 11.7-13.2 cm with compact and thick root mat at 25 days. Seeds treated at 0.2-0.3% (18-20h) showed no disease but severely in untreated seeds in all locations. Seedling height (13.8 cm), leaf age (3.7) and root number (8.5) were better when NPK were applied at 3-4-3 g/tray. Spraying of urea (1%) in addition with MOP, theovit and $ZnSo_4$ at 0.6-0.6-0.2% on 7 and $15^{th}$ days was also effective. PC showed significant growth (29.1-34.5%). Root mat was not good in flooded irrigation (FI). Disease was higher in SI (66.7-97.3%) than FI (0.7-3.7%) in untreated seeds regardless of polythene use. The protocol would be effective for raising mat type seedling in cold environment.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.4
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• pp.55-64
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• 2021

The expansion of upland crop cultivation in rice paddy fields is recommended by the Korean government to solve the problem of falling rice price and reduction of rice farmer's income due to oversupply of rice. However, water use efficiency is significantly influenced by the land use change from paddy field to upland. Therefore, this study aimed to evaluate the water budget of soybean grown in using APEX (Agricultural Policy and Environmental eXtender) model. The amount of runoff was measured in a test bed located in Iksan, Jeollabu-do and used to calibrate and validate the simulated runoff by APEX model. From 2019 to 2020, the water budget of soybean grown in uplands were estimated and compared with the one grown in paddy fields. The calibration result of AP EX model for runoff showed that R² (Coefficient of determination) and NSE (Nash-Sutcliffe efficiency) were 0.90 and 0.89, respectively. In addition, the validated results of R² and NSE were 0.81 and 0.62, respectively. The comparative study of each component in water budget showed that the amounts of evapotranspiration and percolation estimated by APEX model were 549.1 mm and 375.8mm, respectively. The direct runoff amount from upland was 390.1 mm, which was less than that from paddy fields. The average amount of irrigation water was 28.7 mm, which was very small compared to the one from paddy fields.

• Plant Resources
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• v.7 no.2
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• pp.141-146
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• 2004

Frequent occurrence of off-type plants in a given cultivar has been a serious problem in both breeder's and farmer's fields. An experiment was designed to examine the differences in rate of occurrence of off-type plants among Tongil-type cultivars (high yielding cultivars derived from indica/japonica hybridization) from which the possible cause of higher occurrence of off-type plant in a specific cultivar was deduced. Among five Tongil-type cultivars examined for morphological variant in the field, only one cultivar, Dasanbyeo, had off-type plants. When analyzed with SSR markers, off-type plants showed different band patterns from original cultivar, having several extra bands in addition to cultivar-specific band, suggesting that off-type plants were originated from Dasanbyeo, rather than originated from mixing or mishandling of seed materials with other cultivars. The possible cause of off-type occurrence seems to be natural pollination with other cuItivars adjacent to the original cultivar during seed multiplication. This was supported from the observation that self-crossed progeny of the off type plants showed a wide range of variation of agronomic traits which could not be observed when there was a smaller introduction of genes to the fixed germplasm as happened in the case of cultivar mutation. Another evidence supported this idea that Dasanbyeo showed much of difference in floral organ and behavior to other cultivar to be subjected to higher out-crossing than other cultivars examined.

• Korean Journal of Agricultural Science
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• v.21 no.1
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• pp.67-80
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• 1994

Farm land is considered the most important production factor in farm production. Land is not only one of the most scarce resource but also the size of land holding is the key factor in determining the size of farm income in Korea. To increase farm productivity by accepting bio-chemical and mechnical technology, the qualitative improvement of farm land through land consolidation and on-farm development have been carried out by the Korean government. Land consolidation with water resource development makes possible the high-tech-capital intensive farming, internal expansion of farm land and hightening the rate of land intensity in connection with UR problems. This paper contained the present status of farm land base development, allocation of investment by types of farm land development and the econome-trical analysis on the effects of the investment on rice productivity during the past 27 years since 1965. The rate of irrigated paddy area had been increased from 42% in 1965 to 74% in 1991. Land consolidated area out of the total paddy area had been achieved 44.9% and the improved rate of poor drained paddy area was shown 43.5% in 1991. To carry out the above farm land base development projects, the government had procured financial budgets consisting of the G't subsidy, long term loan, foreign loan, the provincial G't subsidy, WFP counter fund and farmer's burden.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.2
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• pp.15-23
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• 2021

This study was conducted to evaluate the field application of the developed recommendation system in organic rice (Oriza sativa L.) paddy and to investigate the mineral nitrogen content in soil and rice productivity. According to the developed system, hairy vetch (HV), rye+rapeseed oil cake (R+OC), rapeseed oil cake (OC) for only basal fertilization (OC-B), OC for split application (OC-S), pig manure compost (PMC), and chemical fertilizer (CHM) were applied to paddy soil at the rate of 107~133 kg N/ha. Results were followed, unhulled rice yield of OC-S (111%), OC-B (110), R+OC (106), HV (101), and PMC (96) were no significantly different with CHM (100). Also there was positive correlation (R²=0.803^*) between unhulled rice yield and cumulative inorganic N in soil. For nitrogen use efficiency of rice, OC-B, OC-S, and R+OC were not significantly different with CHM. In conclusions, the developed organic materials use recommendation system was effective for organic rice productivity. It could be useful for organic farmer to apply the organic materials use recommendation system for rice.

• Korean Journal of Agricultural Science
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• v.23 no.2
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• pp.301-322
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• 1996

This study is first aimed at identifying the possibility of labour saving and production cost decreasing in rice production with respect to seed broad casting technology. Comparison of labour inputs and production costs of rice in-between USA and Korea and recommendation of policy guidelines for the continous rice cultivation are the second objective of this study. Under the WTO system, rice enterprice is the most vulnerable crop in the sense of labour productivity and price competitiveness in the international market. How to adapt labour saving technology and how to decrease production costs are the most imminent problems to be solved in rice production. To achieve the objectives, survey on nine rice enterprice farms were made in Daeho tidal farmland with respect to the size of farm, labour inputs, productivity, farm mechanization and farm land base development. The existing data on labour saving technology by seed broadcasting which had surveyed by Rural Development Administration were collected to compare the surveyed data from Daeho tidal farm land The study results and policy recommendation are summarized as follows; 1. Labour requirements per 10a for rice enterprise farms with seed broadcasting and with transplanting were estimated 11.4 and 18.5hours respectively. 'This above labour inputs were equivalent to 1/3-1/5 of the national average labour inputs of 53.6 hours which were included transplanting and harvesting by machinery. Considering the labour requirement of 1.7 hours per 10a for the USA rice production, Korea rice culture has possibility to decrease labour demand upto USA level of labour inputs. 2. Production cost of rice in Korea were estimated US$4,181 per ha which were higher than that of USA by 3.00 times and production costs per ton were shown as US$313 for USA rice and US$1,018 for Korean rice. 3. Land productivity of rice per 10a in America was reached to 4,325kg and the counterpart of Korea was about 4,181kg in recent year. In the sense of land productivity, both yields of rice were comparable. 4. The price of japonica type rice similar to Korean traditional rice in international market in 1994 was f.o.b US$466 per ton which was equivalent to import parity price of US$830 per ton in domestic market. The price of rice purchased by Korean G't and received by farmers were amounted to US$ 2,013 and US$ 1,663 respectively in the same year. Domestic prices mentioned above were higher than the import parity price as US$830 by 2.0-2.4 times. 5. American rice production competitive to Korean rice was equivalent to 17,012 thousand tons, 1.28% of the world production of rice in 1991 and consumption of rice in America was amounted to 2,633 thousand tons. Exportable quantity of USA rice were estimated as 4,379 thousand tons of which 52.3%, 2,300 thousand tons, were exported indeed in the same year. 6. The quantity of Korean rice produced in 1991 was estimated 1.00% of the world production. The world amount of rice exported in 1991 was reached to 2.45% of the world production of which 34.2% was occupied by USA The remaining quantities of world exported rice were dominated by Tiland, Pakistan and Vietnam where produced indica variety. 7. Under the given technology, labour inputs per 10a for rice production could be possible to save by 70% of the national average labour requirement of 53.6 hours through implmenting complete farm mechanization with land consolidation and on-farm development and improvement of fanning practices like seedbroad casting txchnology etc. On the other hand, prduction costs of rice could be decreased by 10% rather than 49% as target indicated in the Rural Development Counter Measures of Korean Government in 1994 owing to increasing farm mechanization cost and interest on land service with high price. Accordingly production cost of rice per kg could be decreased only by 10% of the 1994 production cost. 8. Rice policy of Korean government in the future should take into account the labour saving technology to solve labour shortage in rural area and to enhance off-farm incomes by creating job opportunities in agro-industrial zones and special production area. On account of the staple food and main energy source for people's health, rice production even encountered vulnerable economic settings should be continued without price distortion policies and discouraging farmer's intention to cultivate rice by importing institutionally the direct income subsidy system.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.300-300
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• 2017

'Saemimyeon' a Tongil-type rice variety (Indica ${\times}$ Japonica), which contains high amylose contents is suitable for rice noodle production. Nowadays, the major parts of rice processing industry that includes products like rice flour and noodles are expected to partially replace wheat flour market. The volume of rice noodle market is getting bigger and can contribute to the rice surplus and farmer's income. This study was carried out to promote productivity and flour-making quality of 'Saemimyeon' by finding the most suitable transplanting and harvesting times. The transplanting days used were May $10^{th}$, May $17^{th}$, May $24^{th}$, May $31^{th}$, June $7^{th}$ and June $14^{th}$ and the planting distance used was 30 x 12cm. In addition, harvesting time was determined by days after heading time (40, 45, 50, 55 and 60 days). The field experiment was conducted at the experimental field in Miryang (Southern plain area of Korea) from 2015 to 2016. Our results suggest that the optimum transplanting days were from May $24^{th}$ to May $31^{th}$ which resulted to an average yield of 748~751kg/10a. Interestingly, yield was sharply decreased below 700kg/10a before May $10^{th}$ and after June $7^{th}$. The average grain filling rate before May $31^{th}$ was more than 83% but it declined to 75% after June $7^{th}$. The average temperature ranges from heading time to harvesting time was $ 21\sim25^{\circ}C$ and the estimated optimal temperature was $23.4^{\circ}C$ which is similar to May $24^{th}$ by regression equation. We found that the optimal harvest time was 45~50 days after heading time. It is hypothesized that low temperature at seed maturation time caused the lower grain filling rate therefore 'Saemimyeon' need to be transplanted before May $31^{th}$ for higher productivity. We found no statistical variation in amylose contents among experimental plots (28.2~30.4%). We conclude that the productivity of 'Saemimyeon' highly depends on temperature that is critical for grain filling stage controlled by transplanting time.

• Korean Journal of Organic Agriculture
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• v.20 no.4
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• pp.631-642
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• 2012

This study was carried out to determine the effect of SCB compost leachate on the growth and yield of rice. Field experiment was conducted on sandy loam soil under the different fertilizer management; 80%, 100%, 130% N level of SCB leachate based on 13kg N/10a of conventional farmer application level and chemical fertilizer as control. The plant height and tiller's number of 80 and 100% N levels of SCB leachate were lower than that of the chemical fertilizer plot. But in the plot of 130% N level of SCB leachate the plant height and tillers was higher than that of chemical fertilizer. And the SPAD reading value of leaf in plot of 130% N level was higher than that of the chemical fertilizer. Rice yield in the 80% and 100% SCB leachate was increased from 12 to 13% that of plot of chemical fertilizer. But rice yield of 130% N-level was decreased 7% compared with chemical fertilizer. Rice quality of the application levels of 80 and 100% SCB leachate levels was significantly better than those of chemical fertilizer and 130% level of SCB leachate. In conclusion, the 100% N application of SCB leachate was improved yield and quality of rice.