• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.5
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• pp.405-412
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• 1992

Growth characters of dry seeded paddy rice was studied at different levels of nitrogen(N) split application (basal : immediately after irrigation : 2 weeks after irrigation: 25 days before heading: heading stage with 10 : 20 : 30 : 20 : 20%, 20 : 30 : 20 : 20 : 10%, 30 : 40 : 0 : 20 : 10%, and 100% basal of slow release urea) in tillage and no-tillage systems. On May 17 in 1990, 6kg /10a of dry seeds of a breeding line of Milyang 95 was broadcasted and covered with a power tiller. Between tillage and no-tillage systems yield and its components, lodging related characteristics, and contents of cellulose, hemicellulose and lignin of culm base were similar. Leaf area index at heading stage was higher in tillage, but lodging index was lower compared with those in no-tillage plot. Culm length, effective tiller ratio, culm base weight, 1000-grain weight, harvest index in slow release N applied plot were higher compared with those in other N treatments. Grain yield of rice among levels of N split applications was similar in tillage, but it was higher in slow release N applied plot in no-tillage if 1kg /10a of additional N was applied as urea at panicle formation stage. At early growth stage N concentration and N uptake were lower in the slow release N applied plot, but higher after heading stage compared with other N treatments. The number of tillers was lowest in slow release N applied plot during the tillering stage, but the number of panicles per hill was similar to other N treatments.

• KCID journal
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• v.11 no.1
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• pp.45-56
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• 2004

This study was performed In order to analyze the changes of electrical conductivity (EC) by the fertilization treatments during the rice owing period in Saemangeum reclaimed tidal land soils. The objective of this study was to offer fundamental data for i

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1004-1008
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• 2012

The importance of environment-friendly agriculture is being magnified as a new growth engine industry in pursuit of low carbon, green growth policies. Since 2010, the Korean government has been promoting the supply of customized fertilizers which were manufactured based on chemical properties of agricultural soils. This aims focused to improve the efficiency of fertilizer used and to protect the agricultural environment. In order to provide technical supports for pushing ahead with the environment-friendly agriculture policies, we have estimated the effects of customized fertilization (CF) on growth and yield of rice and fertilizer reduction compared to conventional fertilization (farm practice fertilization) and single-element fertilization. In rice plant growth and rice yield, no statistically significant difference between the three fertilization treatments was observed. The fertilizer reduction rate with CF compared to conventional fertilization of investigated farms was on average 17%, which covered 6% through 33%. With split ratio, CF 70 reduced the amounts of fertilizer ingredient by 5% compare to CF 50. This paper shows that the customized fertilizer application reduced the amounts of fertilizer used in rice cultivation without decrease of yields.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.731-737
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• 1995

This experiment was carried out at National Crop Experiment Station in 1994 to obtain basic information of growth characters and yield of rice under various nitrogen split application methods on different soil textures in direct seeding on dry paddy. Hwaseongbyeo sown on April 27 by flat drill seeding, and irrigation was done at 3 leaf stage after seedling establishment. Number of seedling stand was 159~177 seedlings per $m^2$ regardless of soil texture and nitrogen application method. Number of panicle per unit area in loam was higher than in sandy loam, and it also was higher in top dressing plots, which were 3 times application at rate of 40-30-30% (3rd leaf stage -7th leaf stage -panicle initiation stage) and 4 times application 10-30-30-30%(basal-3rd leaf stage -7th leaf stage -panicle initiation stage), than in conventional method. Leaf colour, leaf area index and dry matter production at heading stage were highest at top dressing plots among the nitrogen application methods in both sandy loam and loam. Lodging index in top dressing plots increased by low breaking weight with long culm. There were field lodging of degree 3 in top dressing plots. Rice yield in sandy loam, loam increased by 7~9%, 6~9% in top dressing of nitrogen, respectively.

• Korean Journal of Medicinal Crop Science
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• v.6 no.4
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• pp.271-276
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• 1998

This experiment was carried out to determine the effects of topping time and fertilizer split application on the growth and root yield of Scutellaria baicalensis G. In case of stem cutting at 25cm above the soil surface early in July and middle in August, plant height was reduced by 37cm compared with nontreatment, but stem diameter, the number of branch per plant and the growth of root increased. Topping treatment twice produced the highest dry root yield (182kg/10a) of all, 15% higher than nontreatment. When nitrogen and potassium were applied by the basal dressing with 60% and by the top dressing early in July and middle in August with 20% in each time, the growth of plant (both top and root) increased. The dry root yield per 10a in top dressing twice was 12% higher than once.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.1
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• pp.48-54
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• 1987

To search for the optimal nitrogen application method for the machine transplanting to Dongjinbyeo, compared to conventional method, in the various methods of nitrogen split application at different growth stages of rice plant. This experiment was performed at Honam Crop Experiment Station, in 1985 year. The results were as followed; the nitrogen contents of leaf blade was the highest at maximum tillering stage under the conventional method and reduction division stage under the nitrogen top-dressing at panicle initiation and 5 times split application of nitrogen for the whole rice growth stages. CGR, RGR and NAR after heading was highest under 5 times split application of nitrogen for the whole rice growth stages. Relationships between CGR and NAR, NAR and RGR, CGR and RGR showed the positive correlation significantly at each rice growth stage, respectively, and showed more high correlation according to further rice growth stages. The degree of contribution of CGR to rice grain yield was the highest at 20 days after heading. Rice grail: yield was higher under top-dressing of nitrogen at panicle initiation and basal application (30%) + 4 times equal dispensing top-dressing after basal application of nitrogen than conventional method.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.318-324
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• 2000

Field experiment was conducted on a sandy clay loam paddy field in the Experimental Farm of the Kangwon National University for four years from 1995 to 1998 to evaluate the effect of different nitrogen fertilizers on soil property and rice yield. The size of each experimental plot was 75 m2. Basal application of fertilizer to the paddy field was on late April, and rice (cv. Odae) was sown with drill seeding on early May. Irrigation was done at 3 leaf stages after rice seeding. Electrical conductivity in soils treated with phosphate- and resin coated slow release fertilizers were relatively greater than those of the other fertilizer application. Available $P_2O_5$ concentration in soils after rice harvest increased significantly compared that in soil before field trial. Rice yield in transplanting culture were $6.516kg\;ha^{-1}$. The rice yield in the direct seeded paddy was 81.9 percents of the yield in the transplanted paddy. The rice yield in phosphate coated slow release fertilizer was the highest among various fertilizer trials in directly seeded dry paddy, while rice yield was the lowest in the organic fertilizer plus urea application. Rice yield between organic fertilizer plus urea and organic fertilizer application were not significantly different. The green manuring effect of rye in the direct seeded rice paddy in Chuncheon was low due to low temperature and short growth period.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.315-320
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• 1986

The investigation was conducted to find out amounts and ratios of N, P and K fertilizers applied on rice in 410 farmers' fields. The application ranges of N, P and K fertilizers, respectively, were 15.4-16.3, 7.6-8.0 and 8.2-8.5kg/10a for high yielding varieties, and 13.1-13.8, 7.0-7.1 and 6.4-7.7kg/10a for ordinary varieties. N fertilizer was applied in the ratio of 56% at basal dressing, 34% at tillering, 9% at panicle formation and 1% at heading stage. The amounts of soil amendment application were 179-192kg/10a for silicate, 1,031-1,360kg/10a for compost, 420-540kg/10a for rice straw, and 17.8-25.2 ton/10a for red earth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.239-243
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• 2008

This experiment was carried out to elucidate the appropriate split application method of nitrogen fertilizer in infant rice seedlings which show poor seedling growth resulted from extended seedling nursery duration more than 12 days. The 16 day-old infant rice seedling (DOIRS) showed poor seedling growth than 8 day-old seedling. Early growth of transplanted 16 DOIRS was poor, compared with that of transplanted 8 DOIRS. However, the poor plant growth estimated by plant height, tiller number, and the number of newly developed roots was compensated by 70-0-30% (basaltillering-panicle initiation) of nitrogen split application. In 70-0-30% plots among split nitrogen application methods, tiller number, biomass, and leaf area at heading stage of rice showed the highest values. Sixteen DOIRS plots showed lower grain filling and 1000-grain weight, resulted in lower yield of rice than 8 DOIRS plots in the same nitrogen split application. However the lower yield in 16 DOIRS plots was recovered by 70-0-30% of nitrogen split application method to a similar level in 8 DOIRS plots in which nitrogen was split applied by 40-30-30%.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.108-113
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• 1997

A field experiment was conducted to evaluate effect of phosphate coated slow release fertilizer on the directly seeded rice. Odae byeo was seeded by drill under dry condition. The soil was a sandy clay loam soil located in the Experimental Farm of the Kangweon National University, Chuncheon, Kangweon-Do. The yield of rice from the urea applicated directly seeded field was 84.9% of the yield from the transplanted field, and showed no difference between split application treatments. The yield from the phosphate coated slow release fertilizer was the highest showing 110.7% of the yield from the urea application. The yield from the polymer coated slow release fertilizer was 90.4%. The yield from the organic fertilizer 400kg/10a treatment was 81.8% and was 94.8% from the organic fertilizer 600kg/10a treatment. In 1996 experiment, the yield from the phosphate coated slow release fertilizer was higher than the yield from the transplanted field. The $NO_3-N$ and $NH_4-N$ concentrations in soil solution at the depth of 15cm revealed that nitrogen leaching was the highest from the urea N40-0-30-30 treatment, and the lowest from the phosphate coated slow release fertilizer. The phosphorus concentration showed similar pattern. Therefore, use of phosphate coated slow release fertilizer increased rice yield and decreased loss of nitrogen and phosphorus loss.