• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.388-395
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• 2004

This study was carried out to determine the application rate of pig slurry for red pepper. Field experiment was designed with non-fertilizer, chemical fertilizer recommended by soil testing (CFRST) and pig slurry treatments. In pig slurry (PS) plots, pig slurry was applied as basal fertilizer with different equivalents to nitrogen of chemical fertilizer plot (60%: PS60, 80%: PS80, 100%: PS100, 120%: PS120) and chemical fertilizer was top-dressed additionally. Soil organic matter contents after 50 day of planting and after experiment in the plots treated with PS were higher than that of CFRST plot, whereas content of $NO_3-N$ of CFRST plot was higher than that of PS plot. Growth of red pepper were lowest in the non-fertilizer plot. Plant lengths of red pepper at 50 day after planting were similar among the different treatments, plant lengths of red pepper of PS100, PS120 and CFRST at 100 day after planting were higher than those of the PS60 and PS80 plots. But Main stem and stem diameter of red pepper were not different among the treatments. Uptake rate of N, P and K by red pepper plant were 27-44, 9-16 and 41-68% for total N, $P_2O_5$ and $K_2O$, respectively. Utilization of applied fertilizer ingredient by red pepper plant were in the order of PS80> PS60> FRST> PS100> PS120. Yield of red pepper tends to increase by 3% in the PS100 compared with the CFRST, but there was not significant difference between PS120 and CFRST. Chemical component of run-off collected from the furrow of the red pepper field was not different among the treatments. Greenhouse gases ($CH_4$ and $N_2O$) emission of non-fertilizer, PS100 and CFRST during the whole red pepper growth period were 4.0, 4.8 and $5.9kg\;CH_4\;ha^{-1}$, and 0.74, 6.68 and $8.38kg\;N_2O\;ha^{-1}$. Emission of $CH_4$ and $N_2O$ in PS100 was higher than those of CFRST by 23% and 26%, respectively. In this connection, to be used the pig slurry for red pepper, it is required that pig slurry must be decomposed for six months or more. Consequently, pig slurry equivalent to nitrogen of basal fertilizer of CFRST with additional top dressing of chemical fertilizer is recommend as an optimum application rate of pig slurry for red pepper.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.476-482
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• 2001

This experiment was conducted to evaluate the effect of slow-release fertilizer application on quality elevation of onion (Allium cepa L.) in southwestern sea. The slow-release fertilizers used were NIAST (National Institute of Agricultural Science and Technology) I, II, CDU (Crotonylidene Diurea), UF (Urea-Formaldehydes), and IBDU (Isobutylidene Diurea) 30, 50. Growth of the onion plant treated with slow-release fertilizer showed better than the control. However, a rate of infected plant to downy mildew was low as compared with control. Chlorophyll and total nitrogen contents were high in control, whereas firmness, soluble solid content, number and thickness of scaly leaves were high in slow-release fertilizer plot. In early maturing onion, total marketable bulb yield was higher in slow-release fertilizer plot than all other fertilizer treatments. Total marketable bulb yield in late maturing onion treated with slow-release fertilizer was slightly decreased. Decaying loss and the rate of sprouting during storage period decreased in slow-release fertilizer application. In summary, application of slow-release fertilizer increased marketable yield, storability after harvest and also reduced labor needs for top dressing.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.996-1002
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• 2003

A 6 (accession)${\times}$5 (cutting interval) factorial experiment was conducted over two years to investigate the effect of stage of growth on herbage production, nutritive value and water soluble carbohydrate (WSC) content of Napier grass and Napier grass${\times}$Pearl millet hybrids (hybrid Pennisetum). The purpose of the experiment was to determine the optimum stage of growth to harvest the Pennisetums for ensilage. Two Napier accessions (SDPP 8 and SDPP 19) and four hybrid Pennisetum (SDPN 3, SDPN 29, SDPN 38 and Bana grass) were compared at five harvest intervals (viz. 2, 4, 6, 8, and 10 weeks). Basal fertilizers were similar in all treatment plots, although nitrogen (N) top-dressing fertilizer was varied proportionately, depending on the harvesting interval. The application was based on a standard rate of 60 kg N/ha every six weeks. Stage of growth had significant effects on forage yield, WSC content and nutritive value of the Pennisetums. Herbage yields increased in a progressively linear manner, with age. Nutritive value declined as the harvesting interval increased. In particular, crude protein content declined rapidly (p<0.001) from $204g\;kg^{-1}$ DM at 2 weeks to $92g\;kg^{-1}$ DM at 8 weeks of growth. In vitro dry matter digestibility decreased from 728 to $636g\;kg^{-1}$ DM, whilst acid and neutral detergent fibre contents increased from 360 and 704 to 398 and $785g\;kg^{-1}$ DM, respectively. Rapid changes in nutritive value occurred after 6 weeks of growth. The concentration of WSC increased in a quadratic manner, with peaks ($136-182g\;kg^{-1}$ DM) at about 6 weeks. However, the DM content of the forage was low ($150-200g\;DM\;kg^{-1}$) at 6 weeks. Therefore, it was concluded that Pennisetums should be harvested between 6 and 7 weeks, to increase DM content and optimize herbage production without seriously affecting nutritive value and WSC content. Accessions SDPN 29 and SDPP 19 appeared to be most suited for ensilage. It was suggested that WSC content should be incorporated as a criterion in the agronomic evaluation and screening of Pennisetum varieties.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.183-183
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• 2017

In the early part of rice growth, root volume primarily limits the amount of plant-accessible nitrogen (N). Therefore, knowledge of the root development is important for modeling N uptake of rice. The timing when the volume of rhizosphere cover the whole soil is also important to carry out timely top dressing. However, information about initial root expansion and associated N uptake is limited due to intrinsic technical difficulties in assessing below-ground processes. Some studies, however, showed a close relationship between below-ground root and above-ground leaf development, suggesting a possibility that above-ground attributes could serve as surrogates for the root processes. In this study, we investigated the relationship between below-ground and above-ground development of rice. Field experiments were conducted where we cultivated Koshihikari (a leading cultivar in Japan) for four different cropping schedules in 2012. In 2016, Gimbozu (HEG4) and three flowering time mutant lines of Gimbozu (X61 (se13), HS276 (ef7), DMG9 (se13, ef7)) were examined for a single season. Experiments were performed with three replications in a completely randomized design. We monitored ammonium-N concentration ([NH4+-N]) in soil solution by repeatedly taking samples from a porous tubing (10-cm long) vertically inserted at the most distant point from surrounding rice hills. Samples were taken in triplicate (= triplicate tubes) and every three days from transplanting in each experimental unit. For above-ground attributes, leaf area index (LAI) was measured in 2012, whereas soil coverage ratio was estimated by image processing in 2016. Results showed that [NH4+-N] increased gradually after transplanting and then rapidly decreased from a certain day. This distinct drop in [NH4+-N] informed us the timing at which the rice root system reached the point of porous tubing and thus essentially covered the whole soil volume. The LAI at the dropping point was about 0.43 regardless of the cropping schedules in 2012 experiment. In 2016, the coverage ratio at the N dropping point was within the range of 0.12 to 0.19 for four genotypes having different growth durations. In addition, the coverage ratios at seven weeks after the transplanting showed a good correspondence to LAI across the four genotypes. We therefore conclude that both LAI and coverage ratio may serve as robust indicators for root development and might be useful to estimate the timing when the root system fully cover the soil volume. Results obtained here will also contribute to develop models that can predict not only above-ground canopy development but also associated below-ground processes.

• Korean Journal of Environmental Agriculture
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• v.20 no.1
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• pp.15-19
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• 2001

This study was carried out to investigate the effect of application time and amount of rice bran on rice yield, weed occurrence, and chemical change in water as applied at the level of 1.8 Mg/ha (1.8RB) and 3.5 Mg/ha (3.5RB) through field and pot experiment. $Nitrate(NO_3\;^-)$ in the surface water and the percolated water through pot were high in application of 3.5RB, and similar in application of 1.8RB as compared to chemical fertilization. Electric conductivity in surface water were higher by application of rice bran until 25 days after rice bran application. $NH_4-N$ in soil were lower in application of rice bran, and $NO_3-N$ in soil were higher in 3.5RB at tillering stage and panicle formation stage of rice. Rice bran application(3.5RB) showed 68% of weed occurrence as compared to that of chemical fertilization. Rice yield were increased by heavy application of rice bran; 4.41 Mg/ha in 1.8RB and 4.87 Mg/ha in 3.5RB, and top dressing of nitrogen at panicle formation stage caused to increased rice yield by $14{\sim}15%$. Rice yield was also increased by early application of rice bran.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.105-109
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• 2001

Poorly drained coarse textured paddy soils has harmful substances(e.g. $Fe^{2+}$, $H_2S$, organic acid etc.) due to reduction condition, and lower soil temperature during early stage of rice crop. The roots of the rice plant usually were distributed in the surface layer, and prone to lodged. To solve the problems, the study was carried out in the typical poorly drained, sandy loam textured paddy soils during 1997-1998. Coated urea and urea fertilizers were applied on the surface and whole layer mixed respectively. Yield of the surface fertilization of coated urea had increasing tendency but not significant. Advantages of this experiment was saving of about 30% of nitrogen fertilizer and top dressing labour, which would reduce possibility of water pollution.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.1
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• pp.1-11
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• 1971

1. Rice plant grown with silica had more elect leaves and heading was one week earlier with silica than without silica grown in both water culture and Akiochi soil. 2. Silica content of rice plant was apparently increased by silica application and the increase insilica was more increased by bassal application of silica than top dressing. The content of other eements in plant decreased with silica application and the trend was most noticeable in iron. 3. Rice plant low in silica were more susceptible to reaf blast, Helminthosporium, mites and smaller brown plant hopper. 4. There was no significant effect of silica on increasing the dry matter production of rice plant grown on water culture, but silica remarkerbly increased the dry matter production of rice plant grown on Akiochi soil. The increasing effect of silica on rice grown on Akiochi fields was more noticeable than that of grown on Pots. 5. In rice plant grown on Akiochi soil, number of spikelets and percentage of ripened grains were increased by application of silica. The silica effects can be increased by application of well balanced nitrogen and potassium ratio. 6. From these results, it can be concluded that silica seems to have no direct effect on rice growth, but application of silica to Akiochi soil associated with low silica supply may be critical for healthy growth of rice plant, and silica directly related to rice agronomy.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.81-87
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• 1975

A pot experiment was conducted to study the effect of two methods of applying potassium fertilizer to rice. One basic application was compared with the split of same total quantity into four applications as follows: 15 days after transplanting (40%), Ear formation stage (30%), 13 days before heading (20%) and 7 days after heading (10%) Each of these two treatments was carried out on both untreated soil and soil to which wollastonite and lime material had been added. The number of ripened grains or the 1,000 grain weight was increased by application of potassium to untreated soil. However, on soil treated with lime and wollastonite only the number of total grains was increased by potassium application. In both cases, split application of the potassium was more affective than a single basic application. No significant increase in yield was obtained from a single basic application of potassium. However, split application of the same total quantity of potassium did give a significant increase in yield. A negative correlation was found between the content of $K_2O$ and that of other nutrients in the rice plant at two stages of growth. Significant negative correlation was obtained between the content of $K_2O$ and magnesium, phosphorus and nitrogen at ear formation stage, and between the content of $K_2O$ and calcium and silicate including magnesium, phosphorus and nitrogen at heading stage. This result also indicated that the depression of uptake of phosphorus and magnesium at ear formation stage and that of calcium and silicate at heading stage were decreased by potassium split application. However, the degression of uptake of nitrogen at ear formation stage and that of magnesium at heading stage were increased by potassium split application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.3
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• pp.204-212
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• 2019

The optimal application rate of a controlled release fertilizer (CRF) on the growth, yield, and seeding time of rice grown on seedling trays was investigated. The experimental field was located at $37^{\circ}22^{\prime}10^{{\prime}{\prime}}N$ latitude and $127^{\circ}03^{\prime}85^{{\prime}{\prime}}E$ longitude in Hwaseong, Gyeonggi-do, Republic of Korea. The soil in the paddy field was a clay loam. The CRF used in the experiment contained $300g\;kg^{-1}$ of nitrogen, $60g\;kg^{-1}$ of phosphate, and $60g\;kg^{-1}$ of potassium, respectively. The CRF was applied at the rate of 0, 200, 300, 400, 500, and 600 grams on rice seedling tray compared with the field application based on soil testing (control), respectively. The CRF can be applied as single application(which can replace basal fertilizer application and two top dressing application) directly to the seedling tray, and showed the minimum release at the seedling period. Considering the plant growth, nitrogen use efficency and yield of rice, the optimal application rate of developed CRF was 500 g per seedling tray and the yield of rice at this application rate was $4.92{\sim}5.04Mg\;ha^{-1}$. The regression formula between the rice yield and application rates of CRF was as follows ; "$Y=0.0002{\chi}^2+0.0963{\chi}+411.6$($R^2$ : 0.9922) in 2010 and $Y=8E-6{\chi}^2+0.2723{\chi}+344.04$($R^2$:0.9864) in 2011, Y : Rice yield ($Mg\;ha^{-1}$), ${\chi}$ : Application rate (grams) of controlled release fertilizer". The optimum application rates of CRF per rice seedling tray by regression formula was 498 grams in 2010 and 513 grams in 2011.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.1-15
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• 2014

The cultivation situation of Korean wheat of 175 farmers in nationwide for two years, 2010/2011 and 2011/2012, was analyzed to obtain basic data for extension cultivated area and enhancing the self-sufficiency ratio of Korean wheat. Compared to the mean temperature and precipitation in the normal year, the mean temperature was lower before the heading stage and higher amount of precipitation after the heading stage in 2010/2011 and higher the mean temperature and lower amount of precipitation after the heading stage in 2011/2012. Average cultivation career and area were 7.7years and 2.4~3.3ha, Keumkang cv. was mainly cultivated for two years and Jokyung and Baekjoong cvs. were increased cultivation areas in southern part of Korea, Gyeongsangnam-do, Jeolllanambuk-do and Kwangju metropolitan city, including in 2011/2012. Most farmers (144) sown wheat seeds from late October to the beginning November with broadcasting method and the other famers were sown using the drill method. Average amount for basal fertilizer was 29.7 kg/10a with complex fertilizer mixed for wheat and barley cultivation, which was higher amount compared to recommended rate of fertilizer amount by rural development administration. Top dressing using nitrogen fertilizer was applied from in the late February to the beginning March. Heading date was the beginning May in 2011 and the late April in 2012, which the mean temperature from regeneration stage to tillering stage in 2011 was higher than that of 2012. Most farmers harvested wheat in mid-June and Pre-harvest sprouting and Fusarium head blight were occurred in 2011 due to the high amount precipitation during grain filling period.