• KOREAN JOURNAL OF CROP SCIENCE
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• v.15
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• pp.61-67
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• 1974

Field experiment was conducted to disclose some effects of leaf defoliation in heading time and the application of different combinations of nitrogen, phosphorus and potassium on the maturity and yield of paddy rice. The results obtained are as follows; 1.All were components considered were increased as the amounts of nitrogen, phospgorus and potassium applied were increased, except the maturity rate had the tendancy to be decreased with the increase of the above fertilizer applications. 2.As the rate of cutting leaves went higher, the weight of rough rice, the maturity rate and the weight of 1, 000 kernels of perferct brown rice were decreased, and there were significant differences among the treatments of leaf blade cutting. 3. The contribution of each leaf to yield through the maturity, number of spikelets per panicle and 1, 000 kernel weight were 61.87-66.18-65.61% respectively for the flag leaf, 17.50-20.65-23.41%for the 2nd leaf, 12-71-12.73-10.11%for the 3rd lead and 7.93-6.44-0.87%for the 4th leaf respectively. This simply indicared that the effects of the leaves to the yield were decreased as their position went down. This tendency was specially emphasized in the case of the weight of 1, 000 kernels of perfect brown rice.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.703-709
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• 2011

This study was conducted at Korea's typical soil, loamy soil, to figure out the effect of how barley green manure (B), hairy vetch (HV) and the mixed-planting hairy vetch with barley green manure (HV/B) affecting on the yield of rice, usage of nutrient and soil characteristics. Supplying amount of nitrogen from HV, HV/B and B were 172.8 kg $ha^{-1}$, 64.3 kg $ha^{-1}$ and 38.6 kg $ha^{-1}$, respectively. Hairy vetch had the highest plant height and SPAD of rice and next was hairy vetch/barley, chemical fertilizer (CF), none fertilizer (NF), and green manure barley. The amount of rice yield was 5.51 ton $ha^{-1}$ with HV, and 4.24 ton $ha^{-1}$ with HV/B. The chemical characteristics of soil showed lower pH and exchangeable cations (Ca and Mg) at B, HV and HV/B plot rather than that of chemical fertilizer (CF) plot. However, the physical characteristics of soil and the porosity rate showed better tendency at the green manure crops than CF. Nitrogen nutrient balance was showed the most balanced at CF, otherwise field of application of green manure crops were required the appropriate nutrition management if future crops would be cultivated because nitrogen nutrient could be devastated or accumulated.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.152-157
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• 1990

To find out the effect of different patterns of nitrogen and potassium distribution on dry matter yield and botanical composition of temperate pastures, a field experiment was conducted with 6 treatments replicated 3 times in a randomized complete block design. It was lasted from September, 1986 to October, 1989 at the Livestock Experiment Station in Suweon. The results obtained are summarized as follows: 1. In early spring, winter hardiness, growth vigour, cold damage and coverage of grasses with 30% dressing of the total amount of N and K20 fertilizer in spring and at the 4th cutting time respectively were better than those of the other treatments. 2. Average dry matter yield for 3 years with heavy dressing in spring and at the 1st cutting time(l1, 187 kg DM/ha) was much more increased by 9% than that of the equally fertilized treatment(l0,24lkg DM/ha). 3. Changes in the botanical composition showed, in general, the same tendency for all treatments except equal N and K20 distribution. However, grassland vegetation with heavy dressing in spring and at the 1st cutting time was changed into relatively good botanical composition with 76.7% grasses, 22.3% legumes and 1.0% herbs at the end of the experiment. 4. By DM yield and botanical composition treatment 3(40-30-15-0-1570) seemed to be an optimal nitrogen and potassium distribution pattern in a temperate pasture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.3
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• pp.203-208
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• 2012

Field experiment was carried out to identify the proper water exchange interval for the rice cultivation on reclaimed saline soil with different nitrogen levels in southwestern area. The nitrogen fertilizer was applied 14, 17 and 20 kg per 10a by ingredient, and intervals of water exchange treated 3, 6 and 9-day periods from transplanting of rice(Oryza sativa var. Cheongho) to maturing stage in Munpo soil series. The salinity levels ranged 0.10~0.24% and 0.24~0.32% of 3-day and 6-day respectively, whileas it ranged 0.35~0.52% for 9-day interval of water exchange during vegetative stage. Water exchange and nitrogen level showed significant effects on the plant growth, yield, and quality. The yield of milled rice on 3-day and 6-day interval of water exchange showed 497 kg/10a and 492 kg/10a and that were significantly higher than that of 9-day interval in 2008 and 2009. Milled rice yield of 9-day interval of water exchange was lower than that of 3-day and 6-day interval of all nitrogen levels. Plant growth and yield components were not significantly different between 3-day and 6-day interval of water exchange of all nitrogen levels. The combination of nitrogen fertilizer level of 17 kg/10a and 6-day interval of water exchange after transplanting might be recommended for maximum yield realization and minimize salt injury at reclaimed medium saline soil in southwestern area.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.303-305
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• 2011

A study of different levels of Nutrition Elements and the chemical properties of the soil was conducted to determine the yield performance of potato. Application of sulfur, potassium, and Magnesium significantly affected final height, dry matter content, and crispiness of potato. The final pH, organo-nitrogen, phosphorus, potassium, and magnesium content in the soil were significantly affected by S-K-Mg application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.25-32
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• 2016

A long-term field experiment under different fertilization treatments had been conducted to explore the effects of rice yield and soil chemical properties from 1978 to 2008 in Suwon, Korea. The paddy was applied eight fertilization treatments which were F0 (no fertilizer), PK (phosphorous and potassium), NK (nitrogen and potassium), NP (nitrogen and phosphorous), NPK (nitrogen, phosphorus and potassium), NPKC (NPK with compost), NPKS (NPK with straw) and NPKL (NPK with lime). Results of 31 years experiment showed that yield index (the ratio of yield in each treatment to NPK) was the lowest in F0 (0.52) and the highest in NPKC (1.18). Yield index was gradually increased in NPKC but decreased in F0 and NK. The yield index of PK, NP, NPKS and NPKL were not changed long-term treatment. Soil acidity of NPKL showed the highest with pH 7.9, and that of other treatments ranged from pH 6.3 to 6.8. Available phosphorous content of soil was increased in all plots by long-term fertilization, was the highest in PK and NPKC. Soil organic matter was higher in NPKC (1.8%) and NPKS (1.8%) than other treatments (1.3~1.4%) in the early experiment, but that was remarkably increased in only NPKC (2.5%) according to annual long-term application. Thus we suggest that annual compost application with optimum NPK could make stable and sustainable rice production.

• Applied Biological Chemistry
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• v.27
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• pp.47-55
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• 1984

The results of series studies on the ratio of supplements, out-door composting and out-door fermentation induced by using the rice straw as a main substrates at the cultivation of Agaricus bisporus, and the cultivation of Pleurotus ostreatus using the rice straw bundles on its compost are as follows; When rice straw for cultivation of A. bisporus was used as the main substrates in synthetic compost as a carbon source, yields were remarkably high. Fermentation was more rapid than that of barley straw or wheat straw and the total nitrogen content was high in rice straw compost. Use of barley straw compost for cultivation of A. bisporus was shown of low yield compared with rice straw, but when a 50% barley straw and 50% rice straw mixture was used, the yield was almost the same as that using only rice straw. The total organic nitrogen on the compost were shown the positive relation to the yield of A. bisporus, but the ammonium nitrogen negative relation to the mycelial growth and yield of A. bisporus. When rice straw was used as the main substrate for compost media, urea was the most suitable source of nitrogen. Poor results were obtained with calcium cyanamide and ammonium sulfate. When urea was applied three separate times, nitrogen loss during composting was decreased and the total nitrogen content of compost was increased. The supplementation of organic nutrient activated compost fermentation and increased yield of A. bisporus. The best sources of organic nutrients selected were as follows: perilla meal, sesame meal, wheat bran and poultry manure, etc. Soybean meal, tobacco powder and glutamic acid fermentation byproducts which were industrial wastes, could be substituted for perilla meal, sesame meal and wheat bran as organic nutrient sources for compost media. During out door composing of rice straw for cultivation of A. bisporus, using of tuner, composter and tunnel system increased up to 13% of its yield, and also cut down 34% of production Cost. The cultivation of P. ostreatus and utilizing of rice straw and wheat straw was established and its yield was high on the rice straw pots. When the substrates 'Rice straw' was heated by steam at $60^{\circ}C$ for 6 hr. mycelial growth of P. ostreatus was moderately rapid and its yield was high.

• Journal of Microbiology and Biotechnology
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• v.28 no.12
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• pp.2019-2028
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• 2018

Natural astaxanthin mainly derives from a microalgae producer, Haematococcus pluvialis. The induction of nitrogen starvation and high light intensity is particularly significant for boosting astaxanthin production. However, the different responses to light intensity and nitrogen starvation needed to be analyzed for biomass growth and astaxanthin accumulation. The results showed that the highest level of astaxanthin production was achieved in nitrogen starvation, and was 1.64 times higher than the control group at 11 days. With regard to the optimization of light intensity utilization, it was at $200{\mu}mo/m^2/s$ under nitrogen starvation that the highest astaxanthin productivity per light intensity was achieved. In addition, both high light intensity and a nitrogen source had significant effects on multiple indicators. For example, high light intensity had a greater significant effect than a nitrogen source on biomass dry weight, astaxanthin yield and astaxanthin productivity; in contrast, nitrogen starvation was more beneficial for enhancing astaxanthin content per dry weight biomass. The data indicate that high light intensity synergizes with nitrogen starvation to stimulate the biosynthesis of astaxanthin.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.607-612
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• 2007

In this study, we investigated the variations of the kinetic coefficients and Chemical Oxygen Demand (COD), N and P mass used for assimilation of a sequencing batch reactor (SBR) system with the variation of SRTs; SRTs of 7.5, 10.0, 12.5, 15.0 and 20.0 days were tested in one cycle of SBR operation to determine the optimum conditions for the operation of the SBR and estimate its COD, nitrogen and phosphorus removal efficiencies. The SBR system was operated under the conditions as follows: an operation time of 6 hours per cycle, a hydraulic retention time (HRT) of 12 hours, an influent COD loading of $0.4kg/m^3/day$, and an influent nitrogen loading of $0.068kgT-N/m^3/day$. The yield coefficient (Y) and decay rate coefficient ($k_d$) were estimated to be 0.4198 kgMLVSS/kgCOD and $0.0107day^{-1}$ by calculating the removal rate of substrate according to the variation of SRT. Considering total nitrogen amount removed by sludge waste process, eliminated by denitrification, and in clarified water effluent with reference to 150 mg/cycle of influent nitrogen amount, the percentage of nitrogen mass balance from the ratio of the nitrogen amount in effluent (N output) to that in influent (N input) for Runs 1~5 were 95.5, 97.0, 95.5, 99.5, and 95.5%, respectively, which is well accounted for, with mass balances close to 100%.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.89-97
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• 2011

Shallot is a foreign crop introduced from France in 1995 as a new overwintering field crop with an aim to develop as an export crop. This study was conducted to investigate the effect of nitrogen fertilization level and time of supplementary nitrogen fertilization on growth and development of shallot, and to suggest to several problems raised during introductory trial cultivations. Optimum amount of nitrogen fertilization for bulb yield was 24 kg per 10 a. The best time of supplementary fertilization was February and March, with an equal amount in each month. The inorganic element composition of the harvested bulbs was not significantly affected by N fertilization level or by time of supplementary nitrogen fertilization.