• Korean Journal of Soil Science and Fertilizer
• /
• v.35 no.6
• /
• pp.381-386
• /
• 2002

A field experiment was conducted to evaluate the effect of split-application of slow-release fertilizer on the tea plant. The yield of the 1st harvested tea leaves had increased 12% in the slow-release fertilizer(two time split manuring) compared with the traditional manuring(four time split manuring), but that of the slow-release fertilizer to one time split manuring had decreased $6{\pm}3%$. In case of the 1st harvested leave, the contents of chemical components related to quality such as total nitrogen, total amino acid, chlorophyll, vitamin C and theanine were somewhat higher in the leaves of slow-release fertilizer(two time split manuring) treatment than in the traditional manuring, but that of tannin was low. The one time split manuring of slow-release fertilizer had a contrary tendency with two time split manuring treatment. In scoring test, appearance and quality of green tea were more excellent in the two time split manuring compared with one time split manuring of slow-release fertilizer and with the traditional manuring (four time split manuring). Therefore, use of slow-release fertilizer increased yield and quality of tea leaves, and decreased loss of nitrogen, phosphate and potassium.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.15 no.1
• /
• pp.52-60
• /
• 1995

This experiment was carried out to determine the effect of nitrogen application level of cattle sluny(T1:150, T3:250, T53.50 kglha) and chemical fertilizer(T2:150, T4:250, T6:350 kg/ha) on the growth characteristics, dry matter yield and chemical soil property of Sorghum-Sudangrass hybrid [Sorghum bicolor L. Moench]. The results obtained are summarized as follows: Mean stem diameter was significantly increased by increasing nitrogen application level of cattle slurry and chemical fertilizer. Especially, T6 treatment was the highest as 11.1 mm, while T1 treatment w a the lowest as 0.3 mrn. According to the same level of nitrogen application, cattle slurry treaunent(T1, T3 and T5) were showed a lower mean stem hardness than chemical fertilizer treatment(T2, T4 and T6). Especially, T3 treatment was the softest at 0.7 kg/$cm^2$. The dead stubble and tiller number were increased by increasing nitrogen level of cattle slurry and chemical fertilizer(P

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

• Korean Journal of Medicinal Crop Science
• /
• v.11 no.3
• /
• pp.190-194
• /
• 2003

A field experiment was conducted to evaluate effect by split-application of slow-release fertilizer on the tea plant. The yield of the 2nd harvested tea leaves was not different to the slow-release fertilizer of two time split manuring had been doing Sep. or Mar. compared with the traditional manuring had been doing four time split manuring, but that of the slow-release fertilizer to one time split manuring in Sep. had decreased $12.5{\pm}1.5%$. In case of the 2nd harvested leave, the contents of chemical components related to quality such as total nitrogen, total amino acid were somewhat higher in the slow-release fertilizer (two time split manuring) than in the traditional manuring, but those of tannin, and caffeine were low, and those of chlorophyll, vitamin C, free sugar and theanine were not different to out of treatments. In scoring test, appearance and quality of green tea were more excellence in the two time split manuring compared with one time split manuring of slow-release fertilizer and with the traditional manuring (four time split manuring). Therefore, I thought that use of slow-release fertilizer be increased yield and quality of tea leaves, and improved efficiency nature of nitrogen, phosphate and potassium out of soil fertilizer components.

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.6
• /
• pp.547-552
• /
• 2014

This study was conducted to evaluate the influence of fertilization on characteristics of growth and accumulation of anthocyanin in fruit of Omija (Schisandra chinensis Baillon). Nitrogen supply mainly affected growth of fruit and the anthocyanin content in Omija respective of vegetative growth steps. The anthocyanin content in fruit was significantly low in high N supply and non-fertilization. The conjunctive supply of nitrogen and compost tea resulted in a higher anthocyanin content of fruit, total nitrogen content of leaf, and nitrate in soil. This result implies that nitrogen supply to Omija plant, affects the accumulation patterns of anthocyanin in different ways, e.g. it delays the quantitative biosynthesis at low nitrogen supply during fruit maturation or enhances anthocyanin degradation during the final maturation steps.

• Korean Journal of Soil Science and Fertilizer
• /
• v.34 no.3
• /
• pp.153-157
• /
• 2001

To evaluate the effect of liquid pig manure application, the growth and yield of rice and the quality of infiltration water were investigated with application of different amounts of liquid manure. At this study, liquid pig manure was treated with 100, 200, 300 and 400% of recommending nitrogen fertilizer level, respectively. Liquid manure with application rate more than 200% of recommending N fertilizer level (11kg) caused to increase of plant height and number of tiller at panicle formation stage, but it caused the plant disease and pest and plant lodging. In those treatment, number of panicles per hill and number of spikelets per panicle were increased, but yield of rice was less than chemical fertilizer treatment due to low rate of ripeness and 1,000 grain weight. $NO_3-N$ concentration in infiltration water sample collected at 90 cm of soil depth was increased with increasing application amount of liquid manure. With liquid manure application more than 200% of recommending N fertilizer level, it affected negatively on yield and environment such as groundwater quality.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.2
• /
• pp.83-90
• /
• 2004

A pot experiment was conducted to find out the effects of nitrogen content of irrigation water and soil EC on lettuce growth under plastic film house conditions. The square-pots with 42 x 54.5 x 22 cm in length, width and height, were filled with two different soils of different EC. Lettuce was grown with different nitrogen fertilizer application levels including non fertilization (Non-F), decrement of 50% of nitrogen fertilizer recommended by soil testing (DNFRST-50) and fertilization recommended by soil testing (FRST). Two kinds of irrigation water of different nitrogen contents, $6.6mg\;L^{-1}$ and $21.0mg\;L^{-1}$, were used for the experiment. In the low EC soil irrigated with low nitrogen water, fresh weights of lettuce were 6,733, 11,933 and $12,733kg\;ha^{-1}$ for the treatments of Non-F, DNFRST-50 and FRST, respectively. While with high nitrogen water, the yields were 9,733, 13,400 and $12,800kg\;ha^{-1}$, respectively. In the high EC soil irrigated with low nitrogen water, lettuce yields of the Non-F, DNFRST-50 and FRST treatments were 12,400, 12,867 and $10,400kg\;ha^{-1}$, respectively, and with high nitrogen irrigated water lettuce yields of the Non-F, DNFRST-50 and FRST treatments were 13,600, 14,067 and $10,733kg\;ha^{-1}$, respectively. Nitrogen uptake of lettuce from ferilizer in DNFRST-50 was higher than of FRST. Nitrogen uptake of lettuce from irrgation water was found in soils of low EC, but it was not found in soils of high EC. These results suggest that both soil EC and nitrogen content of irrigation water should be considered when we recommend the level of fertilizer application for lettuce.

• Korean Journal of Soil Science and Fertilizer
• /
• v.16 no.2
• /
• pp.131-155
• /
• 1983

Though it has been widely known the nitrogen effects are influenced by soils, varieties, and mineral nutrients in the rice culture, few analyses in relation to the factors increasing nitrogen effect have been studied in Korea. The effects of potassium and silica on the factors increasing nitrogen effects in paddy soils were investigated in accordance with soil improvement practices and nitrogen application methods for the cultivated varieties. The results obtained are as follows. 1. For 413 paddy fields, the yield from soils without nitrogen application ranged from 200 to 850kg/10a and that from nitrogen application did 350 to 1,051kg/10a. The yield increament by nitrogen application varied 50 to 650kg/10a depending on soils. 2. Soil chemical characteristics for high yield were different between with nitrogen and without nitrogen application. In the without nitrogen application, however, contents of organic matter, phosphorous, potassium and calcium of high yield soils were lower than those of low yield, while the available silica content was higher in the former. 3. The yield increased with nitrogen application up to 22.4kg/10a and thereafter it decreased. These phenomena were supposed to be not be decrease of nitrogen uptake but by lowered silica uptake. 4. Clay soil incorporation, deep plough, and inorganic constituents control such as Ca, Mg, and $Sio_2$ were effective as soil improvement praitices. It was appeared that increases of silica content and Ca/Mg ratio were important to increase nitrogen effects. 5. For the correlation between yield and yield components, it was high between yield and panicle in low nitrogen level and so was it between grain yield and ripening rate in high nitrogen. 6. In the urea and super granule urea application plot, recovery rate of nitrogen by plant and soil was high and yield was remarkable high. 7. Regardless of fertilizer types such as ammonium sulfate and urea, the residual nitrogen was about 4kg/10a in both plots of 5.8 and 11.6kg/10a. N applied. 8. The potassium application to soil enhanced the nitrogen efficiency. It was more effective in low potassium soil. 9. Optimum pH value for gel formation in the 4% sodium silicate solution was approximately 6.6. 10. It was suggested that silica could affect to rice plant growth as the inorganic and organic chemical components.

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.2
• /
• pp.72-77
• /
• 1993

This study was conducted to evaluate coated urea complex fertilizer (CUC) application for rice growth and its grain quality on clay loam (Deogpyeong series) and sandy loam (Gangseo series) in southern region of Korea, 1992. The coated urea complex fertilizer used in the experiment was CUC I and II. The CUC I is a complex fertilizer consisting of 18-12-13 for $N-P_2O_5-K_2O$ including 50% of coated urea as nitrogen source, and CUC II is the same complex fertilize as mentioned above but it contains 25% of coated urea. Seventy percent of conventional fertilizer for nitrogen level was applied as basal dose of side-band placement (SBP) and whole plowlayer placement (WPP). Greenish degree of rice leaf color at the late growth stage was high in CUC plots regardless of application method and soil series. Amount of nitrogen uptaken by the rice plant at harvesting stage was mush more in the CUC treatment compared to convential fertilizer, and also much more in CUC I than that of CUC II. In the WPP on clay loam, harvest index of CUC treatment was showed very low level, which was reduced more in CUC II plot. In the CUC treatments, perfect rice grain ratio decreased remarkably, and the notched-belly rice kernel ratios among imperfect rice grain increased drastically. In rice grain, Hon-value(Mg to K.N ratio) decreased, protein and amylose contents increased in CUC application plots in WPP. In addition, gel consitency and alkali spreading value related to eating quality in CUC plots were getting longer and lower, respectively. The yield in CUC plot was similar to conventional fertilizing, but significant decreased in SBP. As a result, the rice grain quality became poor with the coated urea complex fertilizer application, but it could be improved by incorporation with fast-release fertilizer.

• Korean Journal of Soil Science and Fertilizer
• /
• v.38 no.4
• /
• pp.202-210
• /
• 2005

Since understanding on spatial variability of a field is essential to pursue precision agricultural technology, a field study for field variability and variable rate fertilization of nitrogen in a direct seeding paddy was attempted. Variable rate application of nitrogen was designed with soil test, and field application was tested in a direct seeding paddy in the Kimje, Jeonbuk, Korea. The grid samples of soil was collected from the field of which unit size was 35 m by 112 m on February before irrigating of the field. Soil organic matter, available phosphate and silicate, and extractable potassium were analyzed. Variable rate fertilizer recommendation maps of nitrogen for high yielding, HY, and low input sustainable agriculture, LISA, were derived based on the soil analysis. Direct seeding of rice was performed for variable rate treatment, VRT, for the experimental plot in 2001 and 2002, and so did for three volunteer farmers' field in 2003. Yield mapping was performed by harvesting. Economic feasibility of direct seeding of rice by variable rate fertilization was evaluated. Though increased yield of variable rate application and benefit of reducing fertilizer use and environmental impact, the cost for soil test exceeded the total reduced fertilizer cost.