• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.141-146
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• 2017

BACKGROUND: Phosphorus(P) is a vital factor for rice but excess input of phosphorus fertilizer can cause environmental risk and waste of fertilizer resources. We studied to assess the change of available phosphate, P balance, critical concentration of available phosphate under a rice single system. METHODS AND RESULTS: The changes of available phosphate of paddy soil were examined from long-term fertilization experiment which was started in 1954 at the National Academy of Agricultural Science. The treatments were no phosphate fertilization(No fert., and N), phosphate fertilization(NPK, NPKC, and NPKCLS). The available phosphorus concentrations in treatments without phosphate fertilizer (No fert. and N) were decreased continuously. But, after 47 years, available phosphate content in phosphate fertilizer treatment (NPK, NPKC, and NPKCLS) reached at the highest ($245{\sim}331mg\;kg^{-1}$), showing a tendency to decrease afterward. The mean annual P field balance in these treatments (NPK, NPKC, and NPKCLS) had positive values that varied from 16.6 to $17.5kg\;ha^{-1}year^{-1}$, and ratio of residual P were increased. These showed that phosphate fertilizer in soil were converted into the form of residual phosphorus which was not easily extracted by available phosphate extractant. Also, It was estimated that the critical value of available phosphate for rice cultivation was $120mg\;kg^{-1}$ using Cate-Nelson equation. CONCLUSION: We concluded that no more phosphate fertilizer should be applied in rice single system if soil available phosphate is higher than the critical P value.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.3
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• pp.195-202
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• 2017

The volcanic ash soils from the Jeju province have low available phosphate because of the high phosphate fixing power of the soils. Phosphorus fertilizerwas dressed after cultivating green manure crops and before cultivating potatoes in order to investigate potato yields, the available phosphate contents, and phosphorus balance in the soils. Green manure crops cultivated in this study were hairy vetch alone and hairy vetch and rye. During potato cultivation, four treatments were conducted in the experiments; NF (non fertilizer), P fertilizer ($N-P-K=0-25-0kg\;10a^{-1}$), NK fertilizer ($N-P-K=18-0-19kg\;10a^{-1}$), and NPK fertilizer ($N-P-K=18-25-19kg\;10a^{-1}$). There were no differences in the yields of potato stem and tuber from the cultivation plots of different green manure crops. However, in the plots with single-sown hairy vetch and mixed-sown hairy vetch and rye, the yields of potato stem and tuber were higher in the P fertilizer plot than in NF plot. The yield of tuber among the treatments with mixed-sown hairy vetch and rye was the highest in the NPK fertilizer plot. The available phosphate content in soils initially increased with time in all plots, but began to decrease gradually after Oct. 18. The available phosphate contents were high in the plots for phosphate fertilization, and the difference in available phosphate content between non-phosphorus fertilizer plots and phosphorus fertilizer plots increased with time. In the single-sown hairy vetch and mixed-sown hairy vetch and rye plot, the phosphorus balances in NF plot and NK fertilizer plot were very low, while those in the P fertilizer plot and NPK fertilizer plot were high. In conclusion, available phosphate contents in soil and the potato yields were increased by phosphorus fertilization when potatoes planted after cultivating hairy vetch and rye together, compared to hairy vetch alone.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.4
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• pp.341-344
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• 1997

To check the possibility to use the pharmaceutical by product of ginkgo leaf for the improvement soil fertility, a pot experiment was conducted with paddy rice. There were three treatment; NPK alone, NPK+7000kg(air dry)/ha of ginkgo leaf waste and NPK+700 kg of water-washed ginkgo leaf waste (air dry)/ha. The result indicated that the application of ginkgo leaf waste severely retarded the growth of rice. Water washing did reduce the severity of retardation, but the water washed ginkgo leaf waste also retarded the growth of rice significantly. The result of this study suggested that ginkgo leaf waste may contain some growth inhibiting substance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.2
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• pp.175-179
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• 1994

This experiment was carried out to investigate the effect of improved NPK fertilizer and ameliorator application methods on job's tears yield and soil properties in the newly-reclaimed land from 1985 through 1988. Job's tears height of integrated improvement plot was higher than the other plots, and increased from the 1st and the 2nd year, but decreased from the 3rd year when soil conditioner was not applied. Average yield of the crop in the integrated improvement plot was 2.16 t /ha being increased by 49% more than the control plot, and the yield was the greatest in order of integrated improvement>subsoiling>phosphate>lime>compost>control plot. Soil bulk density and hardness of the topsoil decreased to the 3rd year, but increased in the 4th year. Soil pH of the topsoil was not changed significantly by different soil depths and cultivated years.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.138-145
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• 2010

Curcuma longa L. (turmeric) is an important medicinal plant that has been historically used in herbal medicine and in the health food throughout Asia etc. Recently, the demands on rhizome of turmeric are increasing greatly by well-being boom, but there is not enough to meet the demands. To fulfill increasing demands, cultivation system strategies using the organic fertilizers are required to produce a greater amount of rhizome with good quality and yield. A field experiment was conducted to determine the effect of composts, NPK fertilizer(control, F), NPK + swine manure(SM) and NPK + fermentation manure from the wasted oriental medicine materials(OMWM), on rhizome yield and the content of bioactive components for quality. Our results showed that two compost applications can increase both rhizomes(24.1-25.9%) and curcumin(21.7-41.0%) yields, respectively, compared to F control. The content of amino acids increased significantly by SM and OMWM treatments. SM and OMWM application also increased the total phenol yields 7.8 and 8.7 g/10a compared with control 6.3 g/10a, the flavonoid yields 6.3 and 7.3 g/10a compared with control 5.3 g/10a, and also antioxidant activity 21.7 and 41%, respectively, as compared to the control. Especially, OMWM was more effective in total rhizomes yields and bioactivities and in the biosynthesis of curcumin and bioactive components than SM treatments, but the biological pathway was not clear, still. This experiment suggests that curcumin or bioactive components affected by adding SM and OMWM could increase the yields and quality of turmeric.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.194-199
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• 2016

In an experiment conducted at the research field of the National Institute of Agricultural Science, we investigated the effects of mineral fertilizer and rice straw compost on exchangeable potassium and K balances, and rice grain yield under a rice single system. The treatments were no fertilization (No fert.), inorganic fertilization (N), inorganic fertilizer (N, P, K) plus rice straw compost at rates of 7.5, 15.0, 22.5, and $30.0ton\;ha^{-1}$ (NPKC7.5, NPKC15.0, NPKC22.5, and NPKC30.0, respectively). The inorganic fertilizers(N, P, K) were added with standard fertilizer application rate in which nitrogen (N), phosphate ($P_2O_5$), and potassium ($K_2O$) were applied with $75{\sim}150kg\;ha^{-1}$, $70{\sim}86kg\;ha^{-1}$, $75{\sim}86kg\;ha^{-1}$, respectively. Exchangeable potassium for NPKC15.0 NPKC22.5, and NPK30.0 treatments was higher by $0.05{\sim}0.19cmol_c\;kg^{-1}$ than that of NPKC7.5 treatment. Increasing levels of rice straw compost resulted in an increase in the K balance from - $19.9kg\;ha^{-1}yr^{-1}$ (No fert.) to $41.9kg\;ha^{-1}yr^{-1}$ at NPKC22.5 treatment and $62.9kg\;ha^{-1}$ at NPKC30.0 treatment. Continuous application of rice straw compost with NPK fertilizers affected significantly the rice grain yields. The result of the study imply that the application of more than $22.5ton\;ha^{-1}$ of rice straw compost with NPK fertilizers are recommended as the best fertilization practice for enhancement of crop production and K supplying power of soil in the continuous rice cropping system.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.931-939
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• 2019

Biochar is a solid carbon material made by pyrolyzing a biomass under limited oxygen conditions. Biochar has been reported to confer various benefits, such as increased soil productivity, pollutant absorption, and reduced greenhouse gas. In this study, oak pyrolyzed at 600℃ for 3 hours was either powdered or pelleted. Each of the biochar types was added to the soil at a rate of 2%. The control did not receive any biochar while a combination of the biochar and NPK treatment (biochar 2% + NPK) was also included. The cherry tomatoes were grown in greenhouse pots for 50 days to compare the growth characteristics of the different treatments. The cherry tomato with the powdered biochar 2% + NPK treatment had the heaviest plant fresh shoot weight of 276.4 g and the highest chlorophyll content of 59.3 SPAD. The control had the lightest plant fresh shoot weight of 44.2 g and a chlorophyll content of 26.5 SPAD. Both forms of biochar affected the chemical properties of the soil, increased the pH, electrical conductivity, available phosphate, total carbon and total nitrogen and positively influenced the cherry tomato growth and productivity. From the above results, therefore, both biochar forms are suited for use as soil amendments.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.327-334
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• 2014

Emission reduction of $CH_4$ (methane gas) from rice paddy soil is a very important measure for climate change mitigation in agricultural sector. In this study, we investigated the changes in crop yield and $CH_4$ emissions in response to application of biochar and fertilizers. The experimental site is located in Hwasung, Kyunggido and experimental design is the split-plot method with three replicates. Treatments included rice straw (RS) and biochar (BC) amendments nested with the conventional NPK fertilizer (NPK) and slow release fertilizer (SRF). Control was also prepared with the soil with the conventional NPK fertilization with no amendment. Measurement of $CH_4$ emission was conducted during the growing season of 2014 using a dynamic chamber method. The results showed that application of rice straw increased daily $CH_4$ emission rate by 15%, while application of biochar reduced daily $CH_4$ emission rate by 38%. When we combined biochar application with slow release fertilizer, $CH_4$ emission was reduced by 45%. Further, the crop yield was also increased in all treatments compared with the control except for the treatment of rice straw application with slow release fertilizer. Overall results imply that biochar amendment to agricultural soil can be an effective strategy to decrease annual $CH_4$ emission with no reduction in crop yield.

• The Journal of Natural Sciences
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• v.5 no.1
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• pp.29-36
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• 1992

The experiment was conducted to evaluate the effects of organic fertilizer. Sarang of fermented poultry manure. Miwon glutamic acid fertilizer and poultry manure, on the growth and yield of radish cultivated in spring and autumn. 1) The growth of leaf length, leaf weight, root length, root diameter and root weight of radish in two culture types was stimulated in order of NPK, fermented poultry manure + 1/5NK, fermented poultry manure, poultry manure and control treatment, and chlorophyll and nitrogen content of leaf were increased in order of the above mentioned fertilizers.2) Yield decreased in fermented poultry manure plot of 450kg application comparison with NPK plot but the one of 1800kg fermented poultry manure was increased. The yield of 450kg Sarang plot was sufficient as compared with Korean average yield of spring and autumn culture.3) The difference of growth of radish between treatments of fermented poultry manure and NPK was lowered by continuous application of Sarang organic fertilizer.4) Soil nitrogen content and exchangeable Mg were similar in all treatments but soil pH, the contents of organic matter, $P_2 O_5$ and Ca were high in the fermented poultry manure treatment.

• Journal of Plant Biology
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• v.9 no.1_2
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• pp.25-30
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• 1966

The writer presented in the report 7th of this series(Chong, 1959. '62 a.b. '64, '65) the result of fertlizer application on Sasamorpha purpurascens var. borealis with regards to soil conditions, climate, planting position etc. and this report is on the effectiveness of fertilizers by kinds of the new (1-year old) and old(3-to 4 years old) Phyllostachys retticulata. The ineffectiveness of fertilizers for old bamboos aged more than 8-years old has been reported previously. The study site was chosen in a bamboo groven situated at Hyunnae Ri, Okkye Myun, Myungju Gun, Kangwon Do. Each plot was so designed that only one individual remained at the center of a circular area with a dimeter of meters by eliminating the clums and severing the rhizomes, of other individuals around it. And, for the fertilizer test, 10 individuals(the new and old: 5 to 5) were observed per kind of fertilizer used; thus marking the total number of 160 plots in all. The second part of this study was conducted for the potted individuals which numbered 48, successfully established ones out of 55 the transplanted to pots. The 48 were divided into 8 treatments: whole fertilization (NPK＋compost＋human manure); NPK; N; K; Human manure; compost; and the control. Amoung of fertilizers applied was 200 grams for the natural plots and 100 grams for pot; it continued for 3 years and applied twice a year (spring and summer) following the theory of Dr. Koichi-ro Ueda(1954, '60 a.b.). Measurements were taken in August each year. The resutls were confirming the fact that the bamboos require a great deal of fertilizers. The results show the following points: 1) Fertilizers were more effective in the 3 to 4 year old bamboos. 2) The order of effectiveness of fertilizers by kind was the whole fertilization, NPK, and N treatments for Phyllostachys reticulata. 3) Organic matter in addition to commercial fertilizers showed better result than the soil application of the latter due to better soil aeration.