• Korean Journal of Environmental Agriculture
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• v.31 no.1
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• pp.1-8
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• 2012

BACKGROUND: Organic fertilizers in watermelon cultivation are widely used to supply nutrient and organic matter. This study was conducted to investigate the effects of application rate of organic fertilizer on the watermelon growth and soil chemical properties in greenhouse METHODS AND RESULTS: The organic fertilizers used in this experiment were mixed expeller cake (MEC) and mixed organic fertilizer (MOF). The treatments were conducted with 4 levels (1.0 N, 0.7 N, 0.5 N and 0.3 N) on the basis of soil testing nitrogen fertilization (STNF) using MEC or MOF as the basal dressing, and using chemical fertilizers (CF) as the additional dressing on the rest of STNF. These fertilizations were compared to CF 1.0 N (0.3 N as the basal and 0.7 N as the additional dressing) and non fertilization (NF). The leaf area of watermelon in treatment 0.5 N and 0.3 N using MEC or MOF was similar to CF treatment. The absorbed nutrient amounts by leaf, weight and sugar contents of fruit in the 0.5 N and 0.3 N treatments were higher than other treatments. In 0.5 N and 0.3 N treatments using MEC or MOF on the basis of STNF, soil chemical properties such as electrical conductivity (EC), available $P_2O_5$ and exchangeable K concentrations after experiment showed tendency to decreasing or similar level before experiment. CONCLUSION(s): These results suggest that the MEC or MOF application as the basal dressing at the 30~50% level of STNF and CF application as the additional dressing on the rest of STNF be best to maintain adequate nutrient of soil and to increase marketable yield for watermelon.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.379-385
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• 2006

This experiment was carried out to investigate the optimum planting density in low fertilizing cultivation of machine transplanting in rice field of Honam Agricultural Research Institute, NICS for $2004{\sim}2005$. Sobibyeo which belongs to medium maturing variety and Nampyeongbyeo which belongs to medium-late maturing variety were transplanted on May 30. In this experiment, there was no significant difference in heading date between planting density and nitrogen fertilization rate, and heading dates were August 8 in Sobibyeo, and August 14 in Nampyeongbyeo respectively. In relation to lodging character, lodging Index was high where the nitrogen fertilization rate and planting density were high. As planting density increases, panicle number per $m^{2}$ increased irrespective of nitrogen fertilization rate. When nitrogen was 6 kg/10a, rice yield of Sobibyeo was more where planting density was 90 hill per $3.3m^{2}$, and that of Nampyeongbyeo was more where planting density was 80 hill per $3.3m^{2}$. When nitrogen was 9 kg/10a, rice yield of Sobibyeo was more where planting density was 100 hill per $3.3m^{2}$, and that of Nampyeongbyeo was more where planting density was 110 hill per $3.3m^{2}$. Head rice rate of brown rice was higher when planting density increased, and was higher at 6 kg/10a nitrogen rate than 9 kg/10a nitrogen rate in all varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.3
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• pp.308-317
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• 1996

These experiments were conducted to investigate variation of physical characteristics of the culm related to lodging resistance by nitrogen levels under direct seeding on flooded paddy surface. The number of seedling per m$^2$ were from 103 to 110 plants, and seedling ratios were ranged from 66.7% to 71.2%. The lodging occurrence were increased in order to the nitrogen levels 15 kg, 10 kg, 5 kg /10a, and the lodging resistant varieties ; Dongjinbyeo and Cheongmyungbyeo showed less values of field lodging than those of lodging susceptible varieties ; Daecheongbyeo, Palgongbyeo and H waseongbyeo. The lodging resistance was decreased in semidwarf varieties compare with long culm varieties, but Dongjinbyeo, long culm variety has lodging resistance. The occurrence of lodging decreased with lower values in top moment, but with higher values in the breaking moment with leaf sheath. The root dry weight positively correlated with weight of culm base, but modulus of section was negatively correlated with bending curvature, respectively.

• Korean journal of applied entomology
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• v.35 no.2
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• pp.132-136
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• 1996

These studies were carried out to investigate the occurrence of rice insect pests related to different transplanting times and N-P-K-fertilizer levels of paddy field in Southern region of Korea. The population densities of brown planthopper (BPH: Nilaparvata lugens Stal), whitebacked planthopper (WBPH: Sogatella furcifera Horvath), small brown planthopper (SBPH: Laodelphax striatellus Fallen), green rice leafhopper (GRLH: Nephotettix cincticeps Uhler), rice stem maggot (RSM: Chlorops oryzae Matsumura), striped rice borer (SRB: Chilo suppressalis Walker), and rice leaffolder (RLF: Cnaphalocrocis medinalis Guenee) were affected more by transplanting time than the fertilizer levels. The later transplanting time induced the higher population densities of BPH, WBPH, SBPH, GRLH, RSM, whereas SRB and RLF were affected by earlier transplanting time in paddy field. The major pests except GRLH and SRB were increasingly induced by higher N-fertilizer level in the late transplanting.

• Journal of The Korean Society of Grassland and Forage Science
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• v.2 no.1
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• pp.31-34
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• 1980

• Proceedings of the Korean Society of Crop Science Conference
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• 2019.04a
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• pp.73-73
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• 2019

• Korean Journal of Weed Science
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• v.4 no.1
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• pp.19-25
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• 1984

Emergence, growth of weeds and growth, yields of rice (cv. Sam Seung Byeo) were determined at different transplanting times and nitrogen levels. Dominant weed species were Cyperus difformis, Rotala indica, Monochoria vaginalis, Cyperus serotinus, Sagiitaria pygmaea, Scirpus hotarui, and Fimbristylis miliacea. Number of weeds was increased in earlier transplanting time and but decreased in high nitrogen level. Dry weight of weeds was decreased with increase of nitrogen level at early transplanting time (May 26) but increased at nitrogen 8 or 16㎏/10a, Plant height, dry weight, leaf area index, and yield of rice were decreased as transplanting time was delayed but increased as nitrogen level increased. Yield reduction of rice due to weed competition was increased in earlier transplanting time and decreased in high nitrogen level.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.365-371
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• 2007

Objective of this research was to investigate the effect of nitrogen concentrations in the fertilizer solution on growth and development of nutrient deficiency in leaf perilla (Perilla frutesens). The nutrient concentrations in above-ground plant tissue, petiole sap and soil solution of root media were also determined. Nitrogen deficiency resulted in dwarfed growth, small leaves, and bright yellow color of older leaves. The leaves of deficient plants became uniform yellowing in color and finally necrosis occurred on the deficient leaves. Elevation of N concentrations in the fertigation solution from 0 to 20 mM increased the crop growth in leaf length and width as well as fresh and dry weights of above ground plant tissue. That also resulted in the increase of chlorophyll contents. However, light toxicity symptoms such as abnormal leaf surface appeared on crops grown in 20 mM N fertilization. The plant growth was commercially acceptable in the treatments of 10 and 15 mM N. The plants with acceptable growth had 0.9 to 1.25% in N contents of above-ground plant tissue, 800 to $3,300mg{\cdot}kg^{-1}$ in the $NO_3-N$ concentrations of petiole sap, and 28.7 to $47.3mg{\cdot}kg^{-1}$ in the $NO_3-N$ concentrations of soil solution (1:2 extract) at 75 days after transplanting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.4
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• pp.264-269
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• 2016

The present study was conducted to establish the optimal fertilization type and method for no-tillage during the first year of No-tillage (NT) and Conventional-tillage (CT) practices for soybean, using different types of fertilizers. In this experiment, the culm length and stalk diameter showed a greater response to fertilization with surface irrigation than to conventional fertilization. The fastest flowering period (July 28) occurred using chemical fertilization applied via subsurface irrigation. Comparing maturation based on growth characteristics and flowering date revealed that fertilization with subsurface irrigation was more effective for the growth of crops than other methods. Regarding yield, there was no significant difference between livestock and chemical fertilizers in subsurface irrigation, but there were significant differences between these fertilizers when using conventional fertilization methods. Based on the results, livestock fertilizer with subsurface irrigation effectively enhanced crop quantity. Nitrogen absorption of plants using subsurface irrigation was more effective than that using conventional fertilization. Regarding phosphorus absorption of plants, chemical fertilizers showed higher absorption than did livestock fertilizers for both subsurface irrigation and conventional fertilization. Unlike nitrogen, phosphorus was highly absorbed using conventional fertilization. Absorption of phosphorus and potassium were similar but phosphorus was not absorbed using livestock fertilizers applied either using subsurface irrigation or with conventional fertilization.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.144-150
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• 2014

Yams (Dioscorea spp), which are edible or medicinal tuber crops, are a important crop in South Korea. Yams require a high level of soil fertility. The various cultural practices such as fertilizing and plowing were tested for marketable tuber production in Chinese yam (Dioscorea opposita). Tuber yield was also affected by organic matters in soil. Application higher level of organic matters result in increased each tuber weight and tuber yield per unit area. The nutrient absorption quantity of the plant such as nitrogen, phosphoric acid, calcium and potassium was increased from 100~120 days after planting, which time to begin tuber enlargement. The tuber yield was increased when the fertilization increased in quantity. Total yield and marketable ratio were the highest in 31~32 kg/10a of nitrogen fertilizer. From above result, income become larger with increase of marketable yield and quality improvement at 63% (27 kg/10a) level of conventional N fertilization (43 kg/10a). The tuber yield was not significantly different between with in various application level of potash fertilizer. Tuber size and weight decreased accordingly to decreased fertilizing level, so the rates of small tubers increased greatly at cultivation without chemical fertilizer. In considering the accumulation rates of allantoin in Chinese yam tubers, the apt harvest season was after October. The allantoin quantity of it was not influenced with nitrogen fertilizing. Moreover it was advantageous with decrease of chemical fertilizer and appropriate fertilizing in soil environment protection. Commercial tuber's number and yield were increased in trenching before planting with trencher compared with rotavating with tractor.