• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.125-136
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• 1981

This experiment was conducted to study the influence of different cultivation periods on some morphological and agronomic characteristics of rice plant at Iri, the Honam plain, in 1979. Early maturing varieties showed little delay in heading with late transplanting, but intermediate and late maturing varieties showed more than 7 day delay in heading. The number of days required to reach heading was over 55 and 67 days after transplanting in early and intermediate-late maturing varieties, respectively. There was significantly postitive correlation between the length of vegetative stage and the grain yield. The mean temperature during ripening period was significantly correlated with the grain yield and the percentage of filled grains. The length, width, and thickness of leaf increased with earlier transplanting and the elongation degree between upper and lower leaves showed the same tendency. The productivity of dry matter and the translocation rate of photosynthate to spikelet decreased with late transplanting mainly due to low temperature. LAI was also influenced by transplanting date showing close correlation with yield. Early transplanting was desirable for assimilation and dry matter accumulation.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.460-464
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• 2007

This study was carried out to elucidate the proper split application method of nitrogen fertilizer for early dry seeding culture of rice in Honam plain area from 1997 to 1998 in Korea. Dongjinbyeo was selected as rice variety for this experiment. The rate of $160kg\;ha^{-1}$ of nitrogen was split as 40-30-30% of total nitrogen at three different application time combination ; T1) basal-5th leaf-panicle formation(PF) stage, T2) 3rd leaf-5th leaf-PF, and T3) 3rd leaf-7th leaf-PF. The content of $NH_4-N$ in soil at 5th leaf stage was higher in top dressing plots(T2, T3) compared with basal application(T1), at 7th leaf stage it was most in top dressed at 3rd leaf and 5th leaf stage, but there was no difference at heading stage. Amount of nitrogen uptake and nitrogen use efficiency was higher in the order of T3, T2 and T1(basal application). Spikelet number per unit area was more in the order of T3, T2 and T1, but rate of ripened grain and 1,000 grain weight were not significantly different among three nitrogen split application methods. Milled rice yields were higher in top dressed plots compared with basal nitrogen application plots. From the results of this experiment, reasonable nitrogen split application method for early dry seeding culture of rice could be 40-30-30% of total nitrogen at 3rd leaf, 7th leaf and panicle formation stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.459-463
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• 2001

Changes of rice yield and soil physicochemical properties of the dry-seeded rice-barley double cropping system were investigated for 10 years from 1990 to 1999. Generally, seedling stand was more unstable in the rice-barley cropping system regardless of barley straw addition or removal than in the rice single cultivation as indicated by higher standard deviation of seedling stand across year. Rice yield in rice-barley double cropping cultivation was increased due to barley straw application starting from the second year, recording 2 to 19％ increase (average of 9％ for 10 years) due to higher spikelet number. Protein content and Mg/K equivalent ratio were similiar among the barley straw applied field, rice single crop and barley straw removed plots. Also, amylose content was not significantly different among cropping patterns. Physicochemical properties of soil was improved by applying the barley straw; soil porosity was higher and content of organic matter and cation exchange capacity of Ca increased but those of Mg and K did not differ.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.473-478
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• 2003

This study was conducted to clarify the effects of duck free-ranging time on the growth and behavior patterns of duck, pH and dissolved oxygen of irrigation water, and growth and yield of the rice plants in paddy fields. Two paddy fields with each 5 aye were used for 12 hours duck free-ranging plot (12HFR) and 24 hours duck free-ranging plot(24HFR). Body weight gain of the duck was not different between 12HFR and 24HFR. Eating and feather grooming behavior in the 12HFR were significantly longer than those of 24HFR, but other behavior patterns were not so. Working behavior and activities of duck in paddy fields tended to be longer in the 12HFR than in 24HFR. However, any difference was not found on staying time of duck in paddy fields. Although it was not statistically significant, pH and dissolved oxygen of irrigation water tended to be higher in the 12HFR than in 24HFR. The plant height of rice in the 12HFR was significantly shorter than that of 24HFR during the latter half period. The number of tillers per hill was significantly increased in the 24HFR than in 12HFR. The shoot dry weight of rice in the 12HFR was significantly less than in the 24HFR during the heading stage of rice plant, but the root dry weight was not different. The number of spikelets per panicle was significantly less in the 12HFR than in 24HFR, however the percentage of ripened grains was significantly higher in the 12HFR. The yield of rice was not significantly different between the treatments. In conclusion, the free-ranging time of duck for 12 hours in paddy fields promoted eating and working behavior of the ducks. Free-ranging time did give effects on rice traits such as the number of tillers per hill, plant height, shoot dry weight of the rice plant, and spikelet number and percentage of ripened grain. However, the duck growth, pH and dissolved oxygen of irrigation water, and paddy rice yield were not affected by duck free-ranging time. These results might suggest that almost same effect as in 24 hours of free-ranging can be obtained with only 12 hours of free-ranging in daytime.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.156-165
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• 1983

This experiment was conducted to find out the effect of competitive duration and density of Cyperus serotinus Rottb. on rice growth and yield. In plant height of both rice and flatsedge, the compacter density of flatsedge, the higher was plant height. Rice in the 50 days competition with flatsedge had shorter culm than in other competition plots at all density. The panicle number was affected during the tillering stage. The spikelet number per panicle was influenced from 25 days to 50 days after transplanting. Grain maturity ratio and 1,000 grain-weight didn't decrease under competition before 50 days after transplanting. The competition during the tillering stage to the young panicle initiation stage decreased significantly rice yield. The rice competed with low density of flat sedge showed small decrement of yield and its components. The period reaching to maximum stem number of flatsedge become shorter as flatsedge density increased. Number of flatsedge tubers competed with rice produced was 40.1, 16.8 and 11.4 times as much in 1: 1, 1:3 and 1:5 density ratio of rice to flatsedge, respectively. Flatsedge dry matter weight and rough rice yield had the relationship of Y = 601. 95-$0.67x^{**}$.

• 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 CROP SCIENCE
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• v.68 no.2
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• pp.69-80
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• 2023

This study investigated the differences in barley growth at different growth stages (Dec, Feb, and Apr) and the yield at harvest in three groups (G1, G2, and G3) with different climates. Additionally, we measured meteorological differences between areas during the growing season to determine which factors were related to growth and yield differences. We evaluated the chemical composition of soil and the mineral content in leaves during the heading stages. We also recorded the main constituents, amino acids, and mineral compositions of barley seeds grown in different areas. Tiller number/m² in G1 areas was higher than in G2 and G3 when measured before and after overwintering. However, tiller number/m² and dry aboveground plant parts/m² in G2 and G3 areas were higher than in G1. Regrowth, panicle formation, and heading days in G2 areas occurred slightly later than in G1 and G3. However, there was no difference in chlorophyll content (SPAD value) between groups. The yield in G1 areas was 9~15% less than in G1 and G3. The decrease in yield in G2 areas could be due to lower panicle number, spikelet number, and ripening rate. In addition, the decrease in yield in G2 areas is likely because maximum, minimum, and average daily temperatures during the growing season were lower than those in G1 and G3. However, mineral nutrients in the soil were higher in the G2 area than in G1 and G3. The overall mineral content in plants tended to be higher in G1 areas than in G2 and G3. Mineral content such as Cu, K, Mg, and P in G3 areas and crude protein and most amino acids in G2 areas tended to be relatively low compared to other areas. Thus, the G1 area may be suitable for barley cultivation without adverse impacts on barley yield, main constituents, amino acids, and mineral contents compared to the main producing areas in G3.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.5-18
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• 2018

The field trial was performed to evaluate the rice growth and yield in direct seeding cultivation with iron-coated rice seeds. The required time for seed emergence was for 9~11days in the tested direct seeding methods. That was 1~2days earlier in direct seeding with pregerminated seeds than that of direct seeding with iron-coated seeds. The seedling establishment was highest in water seeding with iron-coated seeds but there was not significant difference in terms of statistical analysis. The rice plant height was taller in water seeding with broadcasting method than that of wet hill-seeding methods and in direct seeding with iron-coated seeds than that of direct seeding with pregerminated seeds. The tiller number in the rice plant was the highest in machine transplanting at 30days after direct seeding(June 17) and in water seeding with iron-coated seeds at 45days after seeding(DAS) and 60DAS. The tiller number of 75 and 90DAS in the tested rice cultivation methods being with 352~405/m² was not significantly different in terms of statistical analysis. The heading time was not different in rice direct seeding methods but 2 day earlier in direct seeding with iron-coated seeds than that of direct seeding with pregerminated seeds. The culm length was the highest in water seeding with iron-coated seeds and the panicle length was the longest in wet hill-seeding with pregerminated seeds. The panicle number per m² was highest in water seeding with iron-coated seeds but not significant difference among the tested rice cultivation methods. The water seeding with iron-coated seeds resulted in the highest spikelet number per m² and the heaviest grain weight of brown rice. Percentage of ripened kernel was the highest in wet hill-seeding with iron-coated seeds. But there were not significant among the tested rice cultivation methods. The milled rice yield in direct seeding methods was 3~21% higher than that in machine transplanting. Water seeding with iron-coated seeds recorded the highest milled rice yield being with 6.86t/ha.The occurrence of sheath blight was high according to machine transplanting>wet hill-seeding>water seeding. Weed occurrence was the highest in water seeding with pregerminated seeds. Weedy rice occurred not in machine transplanting but occured 0.6~0.7% in direct seeding methods with pregerminated seeds and 0.1% in direct seeding with iron-coated seeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.144-150
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• 2010

The agricultural techniques of environmental friendly using the green manure crops have been required recently more to have the safety agricultural products and to reduce the use of fertilizers and agricultural chemicals. The utilization of green manure crops related closely to cropping system would be very important. The purposes of this study are both to investigate the effects of green manure crops of hairy vetch, legume, and rye, gramineae, and to compare the effects between them in rice cultivation. The hairy vetch and rye were treated as green manure crops into paddy soil at 10 days before the rice transplanting. The plant height was increased gradually from the maximum tillering to the heading growth stage, showing that it was the highest with treatment of conventional cultivation in 2007 and the highest with hairy vetch in 2008. The number of tillers was higher with treatment of hairy vetch and hairy vetch+rye than those with the conventional cultivation. Dry weight was also higher with hairy vetch than that with the conventional, while it was lower clearly in rye than those in hairy vetch and conventional. According to the high tilller number and spikelet number per panicle out of the yield components relatively, the yield of rough rice was increased to about 6% and 8% in 2007 and 2008, respectively, comparing with the yield in the conventional cultivation. Based on these results, the hairy vetch would be a good green manure crop in rice cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.151-157
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• 1998

Fly ash application with a rate of 0, 50, 100, $150Mg\;ha^{-1}$ in clay loam paddy, which had properties of pH 5.3 and low contents of silicate and boron, gave a strongly positive effects on the growth and yields of malting barley showing better responses in bituminous coal fly ash(BCFA) than anthracite fly ash(AFA). Especially, soil chemical characteristics improved greatly by fly ash were pH, available phosphate, exchangeable calcium, available silicate, and boron. Shoot length and the number of tiller till defrosting season appeared the most positive responses by application of BCFA $50Mg\;ha^{-1}$ and AFA $100Mg\;ha^{-1}$. However, the number of spikelet per panicle at heading stage was proportionally increased to the rates of each fly ash. As a result, the grain yields of malting barley were increased to $13.8(4.221Mg\;ha^{-1}){\sim}37.7%(5.106Mg\;ha^{-1})$ by application of BCFA and to $1.1(3.75Mg\;ha^{-1})-20.6%(4.473Mg\;ha^{-1})$ by application of AFA. Protein contents in the grain was the highest in $150Mg\;ha^{-1}$ plot, showing 10.5 and 10.8% by BCFA and AFA application, which were suitable for malting. At harvesting, plants showed 49 and 58% of lodging indices by application of BCFA 100 and $150Mg\;ha^{-1}$, respectively, which were equivalent to two fold values of those by AFA.