• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.221-225
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• 2002

This study was conducted to identify the effects of slow release fertilizer (LCU) on ridge direct seeding on dry paddy of rice as an irrigation water-saying cultural system. During 1999-2000, a series of experiments was carried out at field (Chonbuk series) of the National Honam Agricultural Experiment Station, RDA using Dongjinbyeo. Plant height and culm length during the total growth duration were the longest and panicle umber per $m^2$ was the highest in 100% LCU application rate. Leaf area index and top dry weight were the highest in the 100% LCU application rate. They increased as more LCU was applied. Nitrogen uptake was the highest in 100% LCU application, and N use efficiency was the highest in LCU 60% + FP (fertilization at panicle formation stage) 20% application. Milled rice yield was 7% higher in 100% LCU application rate than that of conventional N application. Ripened grain rate and 1,000-grain weight of brown rice did not differ, but panicle number per $m^2$ and grain number per m2 were the highest at 100% LCU application.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.227-233
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• 1998

To mitigate the methane emission from rice paddy fields, effects of nitrogen fertilizers source and cultural patterns were evaluated on silty loam soils. And a pot experiment was carried out to find out the effects of nitrogen fertilizers on soil pH, Eh, sulfate concentration of soil water in flooded soil. In transplanting cultivation, the total methane emission depending on fertilizers was $32.9gm^{-2}$ for urea ; $30.3gm^{-2}$ for ammonium sulfate ; $26.4gm^{-2}$ for coated urea. Methane emitted in direct seeding on dry soil was $24.7gm^{-2}$ for urea ; $16.7gm^{-2}$ for ammonium sulfate : and $22.8gm^{-2}$ for coated urea. Thus, the methane emission rate of direct seeding on dry soil was 29.7% lower than transplanting. According to the nitrogen fertilizers, the methane emission rate by ammonium sulfate and coated urea were reduced 18.4 and 15.9% in comparison with urea, respectively. In pot experiments, pH in flooded soils depending on nitrogen fertilizers dereased in order of urea > coated $urea{\fallingdotseq}no$ fertilizer > ammonium sulfate and the order was coincided with that of total $CH_4$ emission from flooded soil. Soil Eh was highest in ammonium sulfate application followed by coated urea, no fertilizer, urea. And sulfate concentrations of soil water were in order of ammonium sulfate > coated urea > urea > no fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.4
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• pp.333-336
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• 1987

A liquid waste from methane fermantation was applied on Maize field to determine its effect and optimum application rate on the plant growth. A basal application of liquid waste increased a considerable amount of soil water resulting in an increase of germination. Fresh and dry yields of maize plant increased as the liquid waste application rate increased and same as plant growth. Nitrogen and phosphorus components in plant and soil showed the same tendency as the yields. The result indicates that the liquid waste is potentially useful source for a fertilizer and irrigation water.

• Asian Journal of Turfgrass Science
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• v.11 no.2
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• pp.97-104
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• 1997

The objective of this study was to observe the differences in growth of creeping bentgrass turf to 'polymer coated urea fertilizer' and 'uncoated urea fertilizer', and to analyze durability of fertilizer effect with the 'polymer coated urea'. The experiment was initiated on June 3, 1996, at the Iowa State University Horticulture Research Station, north of Ames, Iowa. The experiment was conducted on an area of 'Penneagle' Creeping bentgrass(Agrostis palustris) maintained at fair-'way mowing height (1.3cm). The study was repeated at the same arrangement beginning on July 25, 1996. Visual quality data, clipping fresh and dry weight, and nitrogen(N) content in the clippings were taken weekly. Quality of the turf increased with increasing N rate. While quality ratings were higher for turf receiving polymer coated urea than for turf receiving uncoated urea at several times following treatment, but not significant. Fresh and dry clipping weights were quite variable during the trial. Visual quality rating and clipping yields improved with increasing rates of N but these differences were not statically significant between polymer coated and uncoated urea treatment. The durability of fertilizer efficiency in polymer coated urea was not last longer compare with uncoated urea from two weeks after treatment. Higher rates of N application increased the concentration of N in tissue but no significant differences between turf plots receiving polymer coated and uncoated urea. Key words: Polymer coated urea, Creeping bentgrass, Fertilizer, Turfgrass.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.214-219
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• 2008

An experiment was conducted to evaluate the effects of nitrogen (N) level on the dry matter (DM) yield, N concentration and oxalate content of some tropical grasses, namely Rhodesgrass (Chloris gayana), Guineagrass (Panicum maximum) and Sudangrass (Sorghum vulgare). Three levels of N as urea were applied (Standard- 260, $Standard{\times}2$- 540 and$Standard{\times}4$- 1,060 kg N/ha for Rhodesgrass; Standard- 380, $Standard{\times}2$- 770 and $Standard{\times}4$- 1,570 kg N/ha for Guineagrass and Sudangrass) in a completely randomized design and grasses were harvested twice at approximately two-month intervals. Dry matter yield tended to be higher with increased rate of N fertilizer in all species, while further additional N ($Standard{\times}2$ or $Standard{\times}4$) did not significantly (p>0.05) further increase DM yield, when compared with the Standard level of N fertilizer application. There was also a trend towards higher N concentration in plants as N fertilization increased in all species and it was increased significantly in Rhodesgrass and Sudangrass (p<0.05 or p<0.01, respectively). Further additional N ($Standard{\times}2$ or $Standard{\times}4$) application showed no significant (p>0.05) differences on oxalate content in plant tissue within species, when compared with the Standard level of N. The Rhodesgrass contained 0.11, 0.13 and 0.15% soluble oxalate and 0.23, 0.25 and 0.27% total oxalate with Standard, $Standard{\times}2$ and $Standard{\times}4$ level of N application, respectively. The Guineagrass contained 0.54, 0.50 and 0.42% soluble oxalate and 1.60, 1.56 and 1.45% total oxalate with Standard, $Standard{\times}2$ and $Standard{\times}4$ level of N application, respectively. The Sudangrass contained 0.06, 0.15 and 0.12% soluble oxalate and 0.22, 0.22 and 0.21% total oxalate with Standard, $Standard{\times}2$ and $Standard{\times}4$ level of N application, respectively The results from this study suggest that these grasses do not use further addition of N fertilizer ($Standard{\times}2$ or $Standard{\times}4$) to form high content of oxalate salts, when compared with the Standard level of N. In addition, the levels of oxalate present with these grasses are quite low as far as toxicity to animals is concerned.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.471-475
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• 2001

This experiment was conducted to evaluate the effect of slow-release fertilizer on warm type garlic cultivation in the Southwestern region of Korea. The slow-release fertilizers used were UF(Urea-Formaldehydes)70, 100, 130, CDU(Crotonylidene Diurea)100, and IBDU(Isobuty- lidene Diurea)100. The slow-release fertilizer treatment slightly increased plant height, leaf sheath diameter, and leaf number compare with conventional fertilizer treatment. Also, large bulb rate, nitrogen and pyruvic acid contents of garlic in slow-release fertilizer plot were higher than other treatments. Application of slow-release fertilizer increased the commercial yields.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.243-248
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• 2009

Chinese cabbage cultivation has been typically practiced in alpine sloped farmland in Gangwon province, and caused severe soil erosion by soil disturbance like tillage. Cultivation of wild edible greens such as Aster scaber Thunb. and Ligularia fischeri Turcz. could be one of alternative ways to reduce soil erosion, because their residues become stubble mulch after harvest, and there is no need for tillage every year. Therefore, the objective of this research was to estimate the effect of nitrogen application rates for the maximum production of Aster scaber Thunb. and Ligularia fischeri Turcz. in the early cultivation stages. Total N contents of Aster scaber Thunb. and Ligularia fischeri Turcz. increased with the increment of fertilizer application rates. Maximum growth of Aster scaber Thunb. and Ligularia fischeri Turcz. was observed with the highest rates of fertilizer. We obtained the relationship between Aster scaber Thunb. and N application rate, as y = $-0.296x^2$ + 73.82x + 5246 (R = 0.998). There was no significant difference for Aster scaber Thunb production between N application rates for 120 and 160 kg/ha. Also, the relationship between Ligularia fischeri Turcz. and N application rate was y = $-0.135x^2$ + 32.86x + 1529 ($R^2$ = 0.965) in the first year trial after transplanting.

• Korean Journal of Soil Science and Fertilizer
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• v.17 no.3
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• pp.274-282
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• 1984

In order to study the effect of seed-fertilizer vertical distance with soil moisture and fertilizer levels on the emergence and initial growth, barley cv. Olbori was seeded in the pots filled with sandy loam or loamy sand soils which were adjusted to 80-100% (higher soil moisture) or 50-60% (lower soil moisture) of soil moisture retention percent at 1/10 atmosphere tension. Prior to seeding of barley seed-fertilizer distance was appropriately controlled by adding soils after dressing fertilizer at three levels-normal application ($N:P_2O_5:K_2O=6-9-7kg/10a$), 50% increase of normal dose and double application. In addition, germination experiment was conducted in the various concentrations of fertilizer solutions under room temperature. The results are summarized as follows; 1. Seed-fertilizer vertical distance must be more than three centimeters to avoid from the decrease and retardation of emergence and poor initial growth of bareley by fertilizer application. 2. Emergence of barley more decreased and retarded in sandy soils than loamy soils and was decelerated with increase of application rate in fertilizer and decrease of soil moisture content. 3. Germination rate remarkably decrease from 0.4 percent of nitrogen solution and 0.5 percent of potassium solution and reached zero at 2.3 and 2.4 percent of nitrogen and potassium solutions, respectively. 4. Germination of seeds affected by concentrated fertilizer solutions was remarkably recovered with dilution degree of fertilizer solution.

• Korean Journal of Environmental Agriculture
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• v.18 no.2
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• pp.140-147
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• 1999

Since the national land area is small and the fanning land occupies only 24% of total land area in Korea, the promotion of agricultural productivity is urgent. In this process, the application rate of chemical fertilizer, which is the major pollution factor at agricultural non-point sources, has been increasing in every year. The present study examined difference of runoff loading of nitrogen and phosphorus by rainfall intensity(above 100mm, 80-100mm, 50-80mm and 30-50mm). Runoff loading of nitrogen and phosphorus by rainfall intensity has differences under similar rainfall intensity. We are considering that these results were affected by rainfall intensity as well as hydrological condition, soil management, whether or not fertilizer application, cropping, rice straw and plowing.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.4
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• pp.61-70
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• 2019

This study aimed to investigate the physicochemical characteristics of fish meal, bone meal, and sesame oil cake, which are readily available by-products from agriculture and fisheries, during the process of liquid fertilizer fermentation, and to examine the effects of liquid fertilizer application on seed germination and growth of tomatoes. During processing the fermentation for liquid fertilizers by using fish meal, bone meal, and sesame oil cake liquid fertilizers, the pH of the fertilizer increased in the order of bone meal > fish meal > sesame oil cake, and the concentration increased rapidly up to 30 days in all types of liquid fertilizer. The nitrogen content of the liquid fertilizers increased as fermentation progressed in the order of fish meal > bone meal > sesame oil cake. The phosphorus content increased as fermentation progressed and the highest was 1.0 % in the liquid fertilizer of sesame oil cake. The germination rate and its index of radish seeds were compared for different dilutions of each of the liquid fertilizers. Excluding the 10-fold dilution of the fish meal and oil cake liquid fertilizer, all the treatment groups showed a germination rate ≥ 95 % and the germination index tended to increase with dilution rate of liquid fertilizers. For responses of tomato growth, there were no significant differences among the liquid fertilizer treatment groups; however, the organic content, microbial density, and microbial biomass C in the soil were higher than chemical fertilizer treatment. These results demonstrated that there were differences in the characteristics of liquid fertilizers depending on the materials used, and that liquid fertilizer can be used for nutrition management for the organic crop cultivation.