• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.319-319
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• 2017

Methane is the main greenhouse gas released from rice paddy field. Methane from paddy fields accounts for 11 % of the global total methane emission. The global warming potential (GWP) of methane is 25 times more than that of carbon dioxide on a mass basis. It is well known that most effective practice to mitigate methane in paddy is related to the water management during rice growing season and the use of organic matters. This study was conducted to investigate the effects of tillage and cultivation method on methane emission in paddy. Tillage (tillage and no-tillage) and cultivation methods (transplanting and direct seeding) were combined tillage-transplanting (T-T), tillage-wet hill seeding (T-W), tillage-dry seeding (T-D) and no-till dry seeding (NT-D) to evaluate methane mitigation efficiency. Daily methane emission was decreased on seeding treatments (T-W, T-D, NT-D) than transplanting treatment (T-T). Amount of methane emission during rice growing season is highest in T-T ($411.7CH_4\;kg\;ha^{-1}y^{-1}$) and lowest in NT-D treatment (89.7). In T-W and T-D treatments, methane emissions were significantly decreased by 36 and 51 % respectively compared with T-T. Methane emissions were highly correlated with the dry weight of whole rice plant ($R^2=0.62{\sim}0.93$). T-T treatment showed highest $R^2$ (0.93) among the four treatments. Rice grain yields did not significantly differ with the tillage and cultivation methods used. These results suggest that direct seeding practice in rice production could mitigate the methane emissions without loss in grain yield.

• Journal of Agricultural Extension & Community Development
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• v.17 no.4
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• pp.919-931
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• 2010

Forage barley was developed for decreasing the import of forages, and increasing the farmer' income about ten years ago. Nevertheless of higher of farmer' income, the forage barley' area is slowly increased because of lacking of barely seeds. In order to suggest the plan of the urgent spreading on forage barley, the seed-gathering of forage barley was cultivated on 14-provinces and 291ha on 2009. The cultivation area of kyeungnam, kyeungbuk and chunnam province was more than other provence. The youngyang cultivar was cultivated more than orher cultivar. Seed-gathering amount of Youngyang, Uhoo and Yooyun cultiva was 364,213 and 303MT respectively. There were several problems for seed-gathering of forage barley which were the delay of seeding time and the more seeding amount, and the higher seed drying temperature than that of standard manual.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.6-11
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• 2001

In this lysimeter experiment, temporal changes of water percolation rate, irrigation requirement and ${No}_3$－-N leaching were investigated under different cultural practices that were no-till direct seeding on flooded paddy (NTDSF), till direct seeding on flooded paddy (TDSF), and transplanting. The highest water percolation rate of 3,001 l/$m^2$ was measured in NTDSF. Others were 2,551 l/$m^2$ and 2,210 l/$m^2$ in TDSF and transplanting. Water percolation rate in NTDSF and TDSF was increased by 36% and 15% compared to transplanting. Water percolation rates in all cultural practices were increased remarkably from the reproductive growth stage and relatively large amount of water loss through percolation was measured even after the reproductive growth stage. A total irrigation requirement was 3,469 l/$m^2$ in NTDSF and 2,898 l/$m^2$ in TDSF. That was equivalent to 45% and 21 % of increase compared to 2,389 l/$m^2$ in transplanting. The largest ${No}_3$－-N leaching through the entire rice growing period was 701 mg/$m^2$ in NTDSF and was followed by 494 mg/$m^2$ in TDSF and 465 mg/$m^2$ in transplanting. The ratios to the total amount of ${No}_3$－-N leaching at the vegetative growth stage, reproductive growth stage and ripening stage were 31 %, 41 % and 28% in NTDSF; 21 %, 48% and 31 % in TDSF; and 18%, 48% and 35 % in transplanting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.286-294
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• 1996

This experiment was conducted to determine the rice quality between slowlelease fertilizer(SRF) and conventional fertilizer (CF) with the amount of 100% and 80% under direct seeding on dry paddy field, respectively. In rice quality, the percentage of matured grain and immatured grain was higher in CF with machine transplanting than in SRF with direct seeding, and the less amount of fertilizer applied, the lower percentage of immatured grain was obtained. The percentage of carbohydrate showed the difference between CF and SRF, and higher at the level of 100% applicated than that of 80% application. The contents of fat and ash were higher in CF with less fertilizer, and there was no trend to different cultural methods but it was related to the amount of fertilizer in amylose content. The nitrogen and sodium content of milled rice was high in SRF under machine transplanting as well as direct seeding. Calcium and magnesium content showed high in direct seeding but there was not significantly difference between CF and SRF.

• Atmosphere
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• v.34 no.1
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• pp.35-53
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• 2024

Under the leadership of the National Institute of Meteorological Sciences (NIMS), the first domestic autonomous flight-type weather modification experimental drone for fog and lower-level cloud seeding was developed in 2021. This drone is designed based on a multi-copter configuration with a maximum takeoff weight of approximately 25 kg, enabling the installation of up to four burning flares for seeding materials and facilitating weather observations (temperature, pressure, humidity, and wind) as well as aerosol (PM₁₀, PM_2.5, and PM_1.0) particle measurements. This research aims to introduce the construction of the drone and its recent applications over the past two years, providing insights into the experimental procedures, effectiveness verification, and improvement directions of the weather modification drone-based rain enhancement. In particular, partial confirmation of the experimental effects was obtained through the fog dissipation experiment on December 10, 2021, and the lower-level cloud seeding case study on October 5, 2022. To enhance the scope and rainfall amount of weather modification experiments using drones, various technological approaches, including adjustments to experimental altitude, seeding lines, seeding amount, and verification methods are necessary. Through this research, we aim to propose the development direction for weather modification drone technology, which will serve as foundational technology for practical application of domestic rain enhancement technology.

• Current Research on Agriculture and Life Sciences
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• v.19
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• pp.1-8
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• 2001

This experiment was conducted to determine the effect of nursery soils and seeding density on seedling growth characteristics in automatic facility for raising of rice seedlings. The seedling characteristics were evaluated for the 10-day and 15-day old seedlings grown in six different nursery soils including farm-made soils. Two levels of seeding amount, 250 g and 300 g/tray ($60{\times}30{\times}2.5$ cm), were applied to compare the seedling characteristics according to seeding density on different nursery soils. There were wide difference in soil components among the nursery soils tested. In acidity of nursery soils, 'Bunoog 2' was the highest, pH 5.1, and 'Samkyung' was the lowest, pH 8.6. The content of available phosphate was the highest value, 843 ppm, in 'Bunong 1' and the lowest (74 ppm) in farm-made soils. The total nitrogen content of 'Bunong 1, 2, 3' and 'Weonjo' soils was higher than there of 'Samkyung' and farm-made soils. There was no difference in plant height among three types of 'Bunong' soils (Bunong 1, 2, 3), but the seedling height grown in farm-made soils was shorter than there in other nursery soils. The plant heigh was slightly taller as the increase of seeding amount from 250 g to 300 g/tray, and the difference in plant height was larger in 15-day old seedlings as compared with 10-day old seedlings. Dry weight of seedlings grown for 15 days in three 'Bunong' soils was heavier than those in other nursery soils. Based on the growing characteristics of seedlings grown in different nursery soils, the heat result was obtained from a nursery soil, 'Bunoog 2', among six marketing nursery soils tested.

• Journal of The Korean Society of Grassland and Forage Science
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• v.3 no.1
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• pp.17-25
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• 1982

To clarify the direct effect of potassium and interactions with nitrogen and phosphorus on the yield of pasture plants, fertilizer experiment with varied levels of potassium and nitrogen treatment to grass single seeding, legume single seeding and grass-legume mixed seeding, was conducted for three years from 1977 to 1980. The summary of obtained experimental result may be described as below: 1. Potassium application, at any level of amount, did not show its effect to the establishment of plant population, however potash application responded to help winter hardiness at grass single seeding plot. 2. Potassium effect on the fresh yield at grass single seeding was distinct however, not clear effect was observed at legume single seeding and grass-legume mixed seeding plots. 3. For drymatter yield, the highest yield at legume single seeding was recorded 1.152 Kilograms per 10a are at treatment #4 and the highest yields of grass-legume mixed seeding and grass were recorded 1,093 kilograms (Treatment #3) and 834 kilograms (Treatment #5) respectively. 4. In observation of plant succession, they were found that orchardgrass and tall fescue have increased at grass single seeding plot and Alfalfa was dominant over 90 per cent of plant population at legume single seeding and grass-legume mixed seeding plots. It seems that potash effect was distinct in increasing orchardgrass population. 5. The results of this experiment shown that the maximum yield from grass single seeding was obtained at the plat where applied 20-20-30 kg/10a, $N-P_2O_5-K_2O$ and the maximum yield from legume single seeding was obtained at the plot applied with 8-20-20 kg/10a, $N-P_2O_5-K_2O$. 6. Fertilizer cost for producing one kilogram of dry matter in this experiment was lowest at treatment #1 of grass-legume mixed seeding and highest at treatment #5 of grass single seeding. The largest gross income was obtained from the plots where phosphate application was omitted. 7. From the results of this experiment, it may be recommended that economically optimum fertilizer application for grass single seeding will be 20-20-20- kg/10a, $N-P_2O_5-K_2O$ and for legume single seeding and grass-legume mixed seeding will be 8-20-20 kg/10a, $N-P_2O_5-K_2O$.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.200-222
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• 1992

The results of recent researches for improvement of seedling stand in direct seeded rice on the dry paddy in Korea were summarized as the following ; a variety to be cultivated should be chosen the characteristics of high percentage germination under low temperature, shorter period of shoot emergence, and better growth of the mesocotyl and shoots. Meanwhile, there was 40% increase in seedling stand at the treatment of removal of the seed awn under using the drill seeder. After seeding the rice seed covered with soil of 3cm depth was better seedling emergence and also there was the hightest seedling emergence at the 70% of moisture content of the soil. In addition, the application of the Release containing GA 10% enabled to increase the seedling stand and furthermore it was effective under deep seeding depth. The optimum seeding date should be seeded around May 10 when mean air temperature is above 12-13$^{\circ}C$ so that may establish more less 70% in seedling stand. Based on an appropriate seedling stand of 150/$m^2$, the optimum seeding rate was 5kg/10a. It was the best in seeding method using drill seeder and the most desirable recommended seeding method was the drill seeder in terms of seedling stand. In order to improve seedling stand water management was more effective in canal irrigation and in drainage at 6hr after irrigation following by the seeding process. On the other hand, for the increase of seedling stand under flooded condition a variety might have characters being better germination at low concentration of dissolved oxygen and vertically deeper growing of the crown root. Also, seedling stand was able to increase with the seed coating of $CaO_2$in the flooded soil. It was possible to be seeded on the early part of May being mean air temperature of avove 10$^{\circ}C$ and the optimum seeding rate was 5kg/10a. For an effective water management water would be flooded up to 3cm depth for 2-3 weeks after seeding. The rice plant grown under the direct seeded cultivation might be not so much strong in lodging resistance compared to that grown under the transplanting and moreover direct seeded rice cultivation under flooded condition would be more weak growth of the rice plant than that on dry paddy. Meanwhile, the lodging would be affected by the seeding rate, the soil depth after seeding. and seeding method even in the same variety. In particular, roots in the lodging pattern of direct seeded rice cultivation under flooded condition were largely distributed on the soil surface so that resulted easily in the lodging. In general, the lodging resistance would be greater as seeding rate and amount of N fertilizer application are lower and soil depth after seeding is higher. Among the introduction of different seeding method the high ridged drill seeding method on dry paddy soil resulted in the lowest in the lodging index and also it was lower in the drill seeding method than in the scattering seeding method under flooded condition. In case of more than 150 seedlings per $m^2$ there was a severe lodging due to high lodging index at the 3rd and 4th internodes. The effective lodging prevention was able to at the treatment of the Inabenfide at 45 days before heading and the Uniconazol at 15 days before heading which caused the shortage by 10-15cm in culm length. Also, fertilizer management using split application of nitrogen would be contributed the reduction of lodging at the rate of 20-30-20-20-10%(basal-5th leaf stage-7th leaf stage-panicle initiation stage-heading stage) on the dry paddy soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.1
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• pp.49-53
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• 1998

Direct-seeding has major advantages such as labor and cost saving by eliminating preparation of seed bed and transplanting. But, it required increased input of fertilizers and pesticides because of the extended paddy period. Direct seeding in wet paddy (DSWP) gives faster growth and more uniform seedling emergence than direct-seeding in dry paddy. This research had an objective to develop an efficient N management practices for DSWP with split application of N fertilizer. A paddy field experiment was conducted to evaluate effects of starter N and N-topdressing which was delayed N application until 5-leaf stage, with comparison to transplanting (TP). Total amount of N application were two levels; 110kg and 77kg/ha. The N applications were split four times during rice growth stages; starter, topdressing at 5-leaf stage, top dressing at tillering stage, and topdressing at panicle initiation stage. DSWP had more tillers/$m^2$ than TP, but with the delayed heading. The DSWP plots which received N-topdressing at 5-leaf stage without starter N had higher leaf area index (LAI) and leaf greenness than the TP plot. Also, these DSWP plots had high leaf-N concentration at the heading stage, as calculated from leaf chlorophyll meter readings. Rice yield in DSWP with N-topdressing at 5-leaf stage was significantly higher than that in TP and in DSWP with starter N. Energy and N use efficiency were improved in DSWP with N-topdressing at 5-leaf stage. But, there were no significant differences in grain yield between the two levels of total amounts of N applications, 77kg and 110kg/ha. We concluded that starter N could not be used effectively by rice seedlings, but topdressing N at 5-leaf stage was an efficient N management for rice growth and yield in DSWP system.

• Journal of Practical Agriculture & Fisheries Research
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• v.12 no.1
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• pp.29-38
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• 2010

This research was conducted to improve a hill seeding technology under puddled wet soil condition for direct seeded rice. There were severe constrains in hill sowing method under puddled wet soil such as a bird damages, dryness of seeds sown due to strong sunlight in May and buoyancy of seeds and young seedlings after raining and irrigation particular under strong wind. Thus, we have adopted a sandy type(<2mm) silicate covering method in Bokto drill seeding technology for a hill seeding method as well. The average silicate amount in order to cover seeds sown was of 840kg/ha which was evaluated to a proper volume for those problem solution and farmer's handling during sowing operation. In this experiment there was an additional problem like a precious hill drop of rice seeds, covering of silicate over hill seeded rice and seed broken during roller operation.