• Korean Journal of Soil Science and Fertilizer
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• v.39 no.2
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• pp.102-108
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• 2006

It is very important to improve fertilizer use efficiency for the saving of fertilizers and for environmental purposes as well. However, there was no effective ways for the fertilization in the mid of growth under the plastic film mulching cultivation so far. For this, a Band Spotty Fertilization (BSF) machine was developed recently. So, we tried to establish a low input fertilization technique using this BSF machine in the vinyl mulching cultivation of onion (Allium cepa L.). Fertilization efficiency, soil properties, and crop yield were examined and compared among treatments from 2000 to 2001. The content of exchangeable K in soils were higher after fertilization but that of available $P_2O_5$ was lower than before the experiment in all plots. The content of nitrate-N was highest at the early growth stage, and higher in BSF plots than that of conventional fertilization (CF). BSF plot showed higher growth rate, and uptake amount of nitrogen of onion by 59-69% than that of CF. N use efficiency in BSF was higher in the order of two time-split application, one time-split application, and three time application. K use efficiency was high 13-17% BSF plots than that in CF($63kg\;ha^{-1}$) plots. The amount of residual N in soils was high by 8-14% in BSF plots compared to that in CF plots, and the loss of N was lowered 26-34% by BSF. Also, the amount of residual K in soils was high by 13-18% and the loss of K was low by 29-31% in BSF plots compared to that in CF plots. The yield of onions increased by 7-13% by BSF due to increased diameter and weight of bulbs. As the results, N fertilization efficiency increased by 22-42% by BSF.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.8-14
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• 2013

The newly developed fertilizer is the slow-releasing fertilizer which can be used as a basal fertilizer without no additional fertilization at tillering stage. It has 30-4-6% of $N-P_2O_5-K_2O$ and was coated with mixture of LDPE (Low density polyethylene), EVA (Ethylene vinyl acetate), BDP (Bio degraded polymer), TALC and nonionic surfactant for the controlled release up to 50 days after application. Coating materials were designed to be decomposed naturally. This fertilizer can be applied directly to the seedling tray mechanically just before transplanting, resulting in significant labor saving effect. The developed slow-release fertilizer, which can replace both basal fertilization and top dressing at tillering stage by single application directly to seedling tray, showed the highest release at 14~21 days after transplanting. Considering the plant growth at different growth stages and yield, the optimal application rate of developed slow-release fertilizer was 300 g per rice nursery tray and the yield of rice at this application rate was 5.25 MT/ha. Rice quality in terms of head rice grain ratio, amylose content, whiteness, and taste value decreased as fertilization rate increased from 200 g to 500 g per nursery tray. Fertilization rate based on quantity of fertilizer ingredients (N, P, K) was reduced by 49.3% compared to the standard application rate and there was 49.2% reduction in labor input for fertilization.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.352-357
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• 2007

We investigated effects of concentration and duration were investigated in order to promote efficiency of $CO_2$ enrichment in winter. The treatments were conducted with two levels of $CO_2$ concentration, namely 400 ppm, 700 ppm, two levels of duration, 3 h (9:00-12:00), 6 h (9:00-15:00), and control (nonenrichment $CO_2$). Fresh weight of leaves increased under longer exposure to $CO_2$ and higher $CO_2$ concentration. Fresh weight of stem and root increased under longer exposure to $CO_2$, but decreased under higher $CO_2$ concentration. Total dry weight increased under longer exposure to $CO_2$ and higher $CO_2$ concentration. Combination treatment of longer exposure to $CO_2$ and higher $CO_2$ concentration showed the largest decrease of Root : Shoot dry weight ratio. The $700ppm{\times}6h$ treatment showed higher fruit number and yield than control. The results suggested that the growth under longer exposure to 400 ppm $CO_2$ was better than that under higher $CO_2$ concentration.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.3
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• pp.193-200
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• 2004

This pot experiment was conducted to investigate the effects of systematic variation application of Fe, Mn, Cu, and Zn on forage performance of orchardgrass and white clover. The treatments of systematic variation were 0/100, 25/75, 50/50, 75/25, and $100/0\%$ in the Fe/Cu(trial-1), Mn/Zn(trial-2), and Fe+Cu/Mn+Zn(trial-3), respectively. The treatments of Fe/Mn/Cu/Zn(trial-4) were composed of $70\%$ in main element and $10\%$ in other 3 elements, respectively. 1. By the systematic variations of Fe, Mn, Cu, and Zn, the yields were more significantly influenced in white clover than in orchardgrass. In addition, the yields of white clover were closely correlated to the trends of root/nodule growth and flowering. In the Fe/Cu trial, the relatively high yields were obtained at the $100/0\%$ in orchardgrass and at the $75/25\%$ in white clover. The yields of white clover were more negatively influenced by the 100/0(Cu control) than by the 0/100(Fe control). The yields of orchardgrass, however, tended to be opposite to the above trends. 2. In the Mn/Zn trial, both forages showed generally high yields at the high ratios of Mn/Zn. Compared with orchardgrass, the yields of white clover were greatly decreased by the Mn-deficiency(low ratio of Mn/Zn). The effects of Zn on forage yields, however, were not recognized. 3. In the Fe+Cu/Mn+Zn trial, the yields of orchardgrass tended to be slightly different among the treatments. The yields of white clover, however, were relatively' high at the 75/25, and showed a severe decrease at the 100/0 in the 2nd half cuts. In the Fe/Mn/Cu/Zn trial, the yields of white clover tended to be relatively high at the Cu and Zn treatments. It was likely to be caused by the balanced Fe/Mn ratio.

• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.354-358
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• 2014

Field study was conducted to evaluate the agronomic effectiveness of sulphur-bentonite fertilizer. Soil pH was slightly lower tendency to the increase of sulphur-bentonite fertilization, but did not indicate a sharp decline in soil pH. The T-N contents in the $6kg/1000m^2$ plot was higher to 700 mg/kg and the organic matter content was 1.29% in the $3kg/1000m^2$ plot. The content of available-P was also increased to 289 mg/kg in the $6kg/1000m^2$ plot. The growth characteristics of the young radish (Raphanus sativus L.) has significantly more in $3kg/1000m^2$ plot on upper part, and more on under part in $6kg/1000m^2$ plot. Therefore, it is concluded that the application of sulphur-bentonite fertilizer was thought to be effective for the chemical characteristics of soil and crop growth enhancement.

• Journal of Applied Biological Chemistry
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• v.65 no.1
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• pp.1-6
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• 2022

Urea is one of the most common nitrogen fertilizer, but nitrogen use efficiency by crop is low because of rapid hydrolysis of urea and loss of nitrogen in environments. Therefore, it is important to control the nitrogen release from nitrogen fertilizers. In this study, pyroligneous acid (PA) was used as a mean to inhibit urease in soil and prevent excessive nitrogen release from urea. Active ingredient in PA (AI) inhibited ammonification of urea in soil by reducing extracted ammonium nitrogen at 79.7% compared to the soil without PA. In order to evaluate the effect of PA on fertilization efficiency of urea, Chinese cabbage (Brassica campestris var. Pekinensis) was cultivated in soil treated with urea and PA both in pot and field. For PA treatment, half amount of urea was used compared to the amount of urea conventionally applied to Chinese cabbage. The PA treatment with half amount of urea resulted in similar Chinese cabbage biomass to the conventional urea application. Nitrogen concentration in Chinese cabbage was less in PA treatment indicating that Chinse cabbage effectively used nitrogen. Consequently, fertilization of urea with PA will reduce amount of fertilizer and frequency of application.

• Journal of Korean Society of Forest Science
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• v.95 no.1
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• pp.82-90
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• 2006

To examine the effects of nitrogen and phosphorus fertilization on soil nitrogen (N) mineralization, we monitored rates of soil nitrogen mineralization and nitrification in 41-year-old pitch pine (Pinus rigida Mill.) and Japanese larch (Larix kaempferi Gordon) stands growing on similar soil condition in central Korea. For this study, we used the buried-bag incubation method. Fertilizers were applied at three levels [control (C), 200 N kg/ha+25 P kg/ha (LNP), and 400 N kg/ha+50 P kg/ha(HNP)] on 5 June, 1996. Mineral soils (0~20 cm) were incubated 6 times with 45-day-interval from 5 June 1996 to 4 June 1997. Initial soil moisture contents were significantly different among sampling dates and between tree species. Initial soil moisture contents were 32% for C, 28% for LNP, and 26% for HNP at the P. rigida stand, and 31% for C, 31% for LNP, and 33% for HNP at the L. kaempferi stand, respectively. Mean daily N mineralization rates were significantly different among sampling dates and treatments. Annual net N mineralization and nitrification were also significantly different between the two tree species. The annual net N mineralization was 10.6 kg/ha/year for C, 23.3 kg/ha/year for LNP and 6.6 kg/ha/year for HNP at the P. rigida stand, and 2.0 kg/ha/year for C, 12.1 kg/ha/year for LNP and 16.7 kg/ha/year for HNP at the L. kaempferi stand. The annual nitrification was 2.8 kg/ha/year for C, 7.6 kg/ha/year for LNP and 4.3 kg/ha/year for HNP at the P. rigida stand, and 4.3 kg/ha/year for C, 14.8 kg/ha/year for LNP and 6.6 kg/ha/year for HNP at the L. kaempferi stand. The ratios of annual net nitrification to annual net N mineralization were 26% for C, 33% for LNP, 65% for HNP at the P. rigida stand, and 100% for C, 100% for LNP, 40% for HNP at the L. kaempferi stand, respectively. This study indicates that N mineralization in forest may be different by the predominant tree species and fertilization even under similar environments. It is likely that the quality of organic matter might control nitrogen mineralization and nitrification in soils.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.4
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• pp.23-29
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• 2017

This experiment was carried out to compare the productivity and feed value between standard cultivation and organic mixed expeller cake fertilizer cultivation to develop organic cultivation technology except from standard cultivation using chemical fertilizers in the field of forage production. This study was conducted in the rice field of Livestock Research Institute Jacheon-myeon, Gangin-gun Jellanam-do. Organic mixed expeller cake fertilizer consists of 4.0% nitrogen, 65% castor, 30% seeds and 5% fish meal. Sorghum-Sudangrass Hybrids(SX17) was sowed 40kg per hectare on May 25. Test group formation was consisted of a standard group and test treatment. The standard group(Con.) was fertilized chemical fertilizer according to the N-P-K kg/ha, 200-150-150 (basal 100kg, uptake 100kg). Test treatment was carried out organic fertilizer 100%(T1), organic fertilizer 150%(T2) and organic fertilizer 200%(T3) according to the nitrogen content of standard group(Con.). Plant height of harvest time depending on the treatment was that Con was 317cm, T1 was 252cm, T2 was 269cm and T3 was 293cm. Dry matter yield was that Con was 11,386kg/ha, T1 was 6,015kg/ha, T2 was 6,799kg/ha, T3 was 7,627kg/ha. In the test treatment, plant height and dry matter yield increased with increasing fertilizer. Crude protein was the height in Con(7.0%) and Crude protein of test treatment was T1(5.7%), T2(6.3%), and T3(5.1%). As a result of this study, T2 was recommended.

• 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 Environmental Agriculture
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• v.29 no.1
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• pp.12-19
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• 2010

Optimum nitrogen fertigation level by soil testing was determined on the growth and yield of eleven-year-old 'Campbell Early' (Vitis labrusca L.) grapevine in a sandy loam soil from 2005 to 2007. Fifty percent of the annual application of the nitrogen rate (195 kg/ha/yr) was top-dressed as basal fertilizer in all treatments, and the remainders were drip-irrigated with fertigation rate at 25 (12.5% of total N, N 1/4 level of the remainder), 50 (25% of total N, N 1/2 level), and 100 mg/L (50% of total N, N 1 level) in intervals of twice (2.1 mm/times) a week for 12 weeks, and the effect of N drip fertigation was compared to control which the N remainder was applied with surface application as an additional fertilizer. The results showed that chlorophyll content reading in SPAD value and N contents of leaves increased as nitrogen fertigation level increased. Also observed was the growth of the internode and stem diameter of shoots which were longest at N 1/2 level among the treatments conducted both in 2005 and 2006. It was also noted that yield of the fruit was different every year, where average yield for three years was recorded highest in N 1/4 level, and lowest in N 1 level compared to control(surface application). Soluble solid content and titratable acidity of fruit juice were also not significant during the treatments, the maturation of fruits tended to be retarded in N 1 level. The study proved that N 1/4 (N 25 mg/L) levels of fertigation based on soil testing was most efficient in obtaining optimum yield and also, fertigation of grapevine at open field condition reduces the use of nitrogen fertilizer.