• Korean Journal of Soil Science and Fertilizer
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• v.9 no.1
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• pp.33-38
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• 1976

As a basic studies for increasing food production utilizing sandy barren lands and sandy farmlands of low productivity which distributed widely in Korea, an experiment of growing rice-plant on sandy barren land was undertaken as follows. 1. Variety, IR-667 was adopted and the growing method was a nutrient-irrigation culture which aimed to minimize percolation loss in sand with an automatic contineous supplying nutrient solution for supplmenting the sand characteristics. 2. The growth type price-plant after heading was a typical higher yield plant, that is, numerous, small, narrow, and thickend leaves, straight attitute, dense fasciculated etc. though the rooting of plant after planting was delayed because of using paddy-field grown seedling. 3. The adaptability of rice-plants on sandy land seemed to be different by varieties and IR-667 was more adaptable than ordinary Japonica varieties. 4. Even at the period of heading and maturing, the root system of rice-plant grown on sand showed vigorous growth having more activated apical portions. while, even the lower leaves showed flourished state. 5. The suppling of calcium and magnecium in addition to nitrogen, phosphorus and potassium on sand made notable increase of stem number per plant, grain number per stem and yields.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.45-52
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• 1989

The effects of soil properties and N, P and K application rates on the contents of inorganic constituents in the rhizomas of Ji-whang were investigated to know the condition for producing the better quality rhizoma of Ji-whang. Most of soil texture for Ji-whang cultivating belongs to sandy clay loam and sandy loam soils. The nitrogen contents in the rhizomas of Ji-whang was negatively correlated with the contents of organic matter and total nitrogen in surface soils, whereas positively correlated with the sand contents in subsoils. The calcium contents in the rhizomas of Ji-whang were negatively correlated with the sand contents, however, positively correlated with the contents of clay and organic matter in soils. The iron contents was positively correlated with the contents of clay, available phosphorus and exchangeable potassium in surface soils. Much more contents of the inorganic constituents in the leaf of Ji-whang was generally detected than that in the rhizoma of Ji-whang. The contents of iron and copper in the leaf was determined to be more than that in the rhizomas by ten times. In the results of field experiments, it is apparent that the nitrogen contents in the rhizoma and leaf increased with increasing N application rate more than 20kg/10a and 10kg/10a, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.1
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• pp.13-19
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• 1971

In order to establish the method of improving ill drained paddy soil where the accumulation of absorption inhibitor is worried in the earlier stages of rice growth, proper soil is selected and an field experiment is designed having treatments such as lime materials, none sulfate fertilizers, boron and straw etc. The data of yield and plant analysis in different stages of rice growth is eveluated and discussed to obtain following summaries. (1) Significant yield increase was made by the treatment of lime materials such as slacked lime or wollastonite powder, materials inhibiting the activity of microorganisms such as boron and of none sulfate fertilizers lacking inhibitor producing sources. (2) The crop scientifice causes of decreasing yield are the decreasing the number of panicles per hill, grains per panicle and the weight of grains. (3) The plant nutritional causes of decreasing yield are the lowering of nitrogen content throughout the life, phosphate content since young premodia formation stage of plant and the decreased content of magnesium, calcium and silicate in straw at harvesting stage. (4) The causes of lowering the content of various elements in rice plant grown in ill drained paddy soil are suggested as root damage by producing and accumulating absorption inhibitors such as organic acids and hydrogen sulfide etc, from the following observed facts; (a) In young premodia formation stage, attaining to the maximum production and accumulation of absorption inhibitor, the phosphate accumulation in plant was smaller in the phosphate plots than without phosphate plots and much higher in the neutralized plots by adding lime materials. (b) In the plots of straw addition, the potassium content in plant at the young premodia formation stage is very low probabley due to root damage by absorption inhibitor produced from the process of straw decomposition but higher at the stage of harvesting probably due to the immetabolic negative absorption of damaged roots. (c) The effect of boron, known as the inhibitor of microorganism activity to decompose organic matter, is apparent. (d) The effect of nonsulfate fertilizer treatment, having no source of producing inhibitor such as hydrogen sulfide, was significant. (e) All the yield components, decided around the young premodia formation stage attaining to the maximum inhibitor concentration in soil and minimum root activity, are significantly decreased.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.301-306
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• 1989

For the agricultural utilization of Korean forest land resources, which constitutes most of country, the distribution of environment and soil physico-chemical properties of establishable grass lands were clarified. The surveyed data were analized for the reasonable utilization and management of establishable grass land. The results were as follows ; 1. About 50.2% of the grass lands to be established were located under the 200m in altitude. The higher the altitude was, the more the organic matter content. 2. Tall type grass species such as Miscanthus purpurascens, Purple eulalia, and Themeda Japonica covered 71.3% of the natural vegetation in the soils of grass land to be established. 3. The extent of sandy and clayey soils which might be limited in the establishment of grassland was only 3.3%, meanwhile majority of the soils were in the favourable condition for grassland that is about 94% have more than 20cm in available soil depth and about 60.5% of the soils have less than 10% of gravels and stones in the soil profiles. 4. The chemical properties of the prearranged grassland soils were worse than the established grasslands, especially in the content of available $P_2O_5$. 5. The amount of fertilizer recommended for meadow were 286kg of nitrogen per hectare, 271kg of phosphorus, 224kg of potassium and 2040kg of calcium per hectare, but for grazing land were 201, 204, 136 and 1920kg/ha respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.6
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• pp.380-385
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• 2006

To establish law-put fertilization technique and increase of fertilization efficiency during cultivation of vinyl mulching for plant, the improvement of soil properties, nutrition efficiency and yields by band spotty fertilization(BSF) using band spotty applicator was carried out at garlic(Alltuiti sativum L.) field in Honam Agricultural Research Institute from 2001 to 2002 for 2 years. The value of pH and the content of total nitrogen, organic matter, exchangeable potassium and calcium of soil after experiment were increased but the content of available phosphate was decreased than soil before experiment. Uptake amounts of nitrogen fertilized by plants were more than in BSF plots($89{\sim}111kg\;ha^{-1}$) compared to in CF(conventional fertilization) Plot ($76kg\;ha^{-1}$) and nitrogen use efficiency were high in BSF plots(42.9~58.2%) compared to in CF plot(34.9%). Also Uptake amounts of potassium fertilized by plants were more than in BSF plots($34{\sim}58kg\;ha^{-1}$) compared to in CF plot($33kg\;ha^{-1}$) and potassium use efficiency were high in BSF plots(21.6~41.2%) compared to in CF plot(19.4%). Residual amount of nitrogen fertilized on soil were more than in BSF plots($38{\sim}54kg\;ha^{-1}$) compared to in CF plot($22kg\;ha^{-1}$) while loss amount of nitrogen fertilized on soil were less than in BSF plots($32{\sim}53kg\;ha^{-1}$) compared to in CF plot($120kg\;ha^{-1}$). Also Residual amount of potassium fertilized on soil were more than in 100% BSF plot($109kg\;ha^{-1}$) compared to in CF plot($72kg\;ha^{-1}$) while loss amount of nitrogen fertilized on soil were less than in BSF plots($14{\sim}38kg\;ha^{-1}$) compared to in CF plot($113kg\;ha^{-1}$). The BSF plots were increased plant height, leaf number, leaf sheath diameter, bulb diameter and height compared to CF plot. The total yields of garlic were more increased 14~19% because of high large bulb rate, commercial yields in 70, 100% BSF plots compared to in CF plot($102.9Mg\;ha^{-1}$). It was found that 70% band spotty fertilization was more effective as fertilization method to reduce both environmental pollution and chemical nitrogen fertilizer in plastic film mulching cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.457-464
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• 2011

Livestock manure compost (LC) generally contains high content of phosphorus, therefore can be a substitute for phosphorus fertilizers. In this experiment of the cultivation of lettuce in green house, the possibility of LC as a subsitute for phosphorus fertilizer was investigated and the fertilizer efficiency of nitrogen and potassium in LC as compared with chemical N fertilizer (urea) and K fertilizer (potassium chloride) was examined. In proportion to the increase in the application rate of nitrogen fertilizer, soil pH declined, whereas EC and $NO_3$-N content became higher. The application of LC appeared to increase the soil content of organic matter, available phosphate, exchangeable calcium, magnesium and sodium more than that of chemical fertilizer. Supplementation of the K fertilizer by the lack amount from the application of LC resulted in the same exchangeable potassium content in soil with NPK plot in which N, P and K fertilizers were applied by the amount of soil test recommendation. The relationship between soil $NO_3$-N content and nitrogen application rate from fertilizer and compost showed as y=0.57717a+0.19760b+74.65 ($R^2$=0.6347) in which y is the soil $NO_3$-N content (mg $kg^{-1}$), a is nitrogen application rate from fertilizer and b is nitrogen application rate from compost (kg $ha^{-1}$), respectively. From this equation, the supply ability of $NO_3$-N into soil of LC exhibited about 34% (pig manure compost 37.0, chicken manure compost 34.7, cattle manure compost 23.3) of nitrogen fertilizer (urea).

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.364-370
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• 2009

This study was conducted to survey, analyze on the compaction layer and the plow layer at Jeonbug and Jisan series paddy soil, which is the representative soil in fluvio-marine and local alluvium, respectively. The depths of surface soil were 12.6 and 12.7 cm in Jeonbug and Jisan series, respectively. A plowing depth was 10.5 cm. The properties of compaction layer in two soil series were as follows. The hardness were $14.7kg\;cm^{-2}(25.3mm)$ and $8.7kg\;cm^{-2}(22.1mm)$ in Jeonbug and Jisan series, respectively. The thickness were 22.3 cm and 17.8 cm in Jeonbug and Jisan series, respectively. The depth of soil compaction, which means depth from surface, were 15 and 20 cm in Jeonbug and Jisan series, respectively. The relationship between the hardness of compaction layer and the depth of surface soil showed negative correlation, however relationship between the hardness and the thickness of compaction layer showed positive correlation. Soil temperature was lower in compaction layer than in plow layer. This temperature differences between compaction layer and plow layer were from 1.0 to $2.5^{\circ}C$ in Jeonbug series and from 0.7 to 2.1 in Jisan series. The soil physical properties of compaction layer were higher in bulk density and solid phase and lower in porosity and gaseous phase than those of plow layer in all soil series. The soil chemical properties of compaction layer were higher in pH, content of available silicate, exchangeable calcium and magnesium but lower in total nitrogen, content of organic matter and available phosphate than those of plow layer in all soil series. Cation exchangeable capacity and content of exchangeable potassium were similar between compaction layer and plow layer in Jeonbug series, however, in Jisan series these were lower in compaction layer than in plow layer. Elution amount of inorganic nitrogen were lower in compaction layer than in plow layer in all soil series. The content of soluble Fe and Mn were plenty in compaction layer compared with plow layer and these tendency was apparent in Jeonbug series. The water depth decrease were fast until the latter part of June, and were slow as $1{\sim}3mm\;day^{-1}$ for July and August, and were fast again from september. Rice roots distributions as each soil series and tillage method were 25 cm at rotary plowing in Jeonbug series, 30 cm at deep plowing in Jeonbug series, and 20 cm at tillage in Jisan series. Dry weight per m2 at heading stage were much in order of deep plowing in Jeonbug series, rotary plowing in Jeonbug series, and tillage in Jisan series.

• Korean Journal of Mineralogy and Petrology
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• v.34 no.2
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• pp.133-146
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• 2021

Aragonite is one of common polymorphs of calcium carbonate (CaCO₃) and formed via biological or physical processes through precipitation in many different environments including marine ecosystems. It is noted that aragonite formation and growth as well as the substitution of trace elements such as strontium (Sr) in the aragonite structure would be dependant on several key parameters such as concentrations of chemical species and temperature. In this study, properties of the incorporation of Sr into aragonite were investigated over a wide range of various saturation conditions and temperatures similar to the marine ecosystem. All pure aragonite samples were inorganically synthesized through a constant-addition method with varying concentrations of the reactive species ([Ca]=[CO₃] 0.01-1 M), injection rates of the reaction solution (0.085-17 mL/min), and solution temperatures (5-40 ℃). Pure aragonite was also formed even under the Sr incorporation conditions (0.02-0.5 M, 15-40 ℃). When temperature and saturation index (SI) with respect to aragonite increased, the crystallinity and the crystal size of aragonite increased indicating the growth of aragonite crystal. However, it was difficult to interpret the crystal growth rate because the crystal growth rate calculated using BET-specific surface area was significantly influenced by the crystal morphology. The distribution coefficient of Sr (K_Sr) into aragonite decreased from 2.37 to 1.57 with increasing concentrations of species (Ca²⁺ and CO₃^2-) at a range of 0.02-0.5 M. Similarly, it was also found that K_Sr decreased 1.90 to 1.54 at a range of 15-40 ℃. All K_Sr values are greater than 1, and the inverse correlation between the K_Sr and the crystal growth rate indicate that Sr incorporation into aragonite is in a compatible relationship.

• ANNALS OF ANIMAL RESOURCE SCIENCES
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• v.28 no.3
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• pp.97-107
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• 2017

The present study was conducted to investigate the effects on growth performance, nutrient digestibility, and gut health of broiler chickens when a dietary supplementation of multienzymes was added to diets, containing different energy levels. A total of 480 broiler chickens of similar body weight (Ross 308, 1-day-old) were randomly subjected to four treatments. The dietary treatments included a corn-soybean meal-based diet supplemented with: multienzyme (amylase+protease+ mannanase+xylanase+phytase), 0.05% enzyme, and different energy levels (3010 and 3060 kcal/kg). The experimental diets were fed to the chicks in a mash form for 35 days in two phases (1-21 d, phase I; and 22-35 d, phase II). During the overall period, chicks fed with diets supplemented with multienzymes had a better weight gain (p<0.05) and feed conversion ratio (FCR) than those fed with diets without enzymes. There was no difference in the growth rate and FCR among the chicks fed with diets supplemented with enzymes, even though the dietary energy levels were different. The apparent fecal and ileal digestibility of dry matter, gross, crude protein, calcium, and phosphorus were significantly enhanced (p<0.05). The population of cecal and ileal Lactobacillus spp. was significantly increased (p<0.05), and Clostridium spp. and coliforms were significantly decreased (p<0.05) in diets supplemented with enzymes. Villus height and villus height to crypt depth ratio in the small intestine was also significantly enhanced (p<0.05) in diets supplemented with enzymes. In conclusion, multienzyme supplementation had positive effects on the weight gain of broilers, FCR, digestibility of nutrients, and on the growth of intestinal microbiota.

• Korean Journal of Community Nutrition
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• v.24 no.3
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• pp.232-244
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• 2019

Objectives: This study evaluated the nutritional status and prevalence of metabolic syndrome of the people who participated in the KNHANES according to the number of household members. They were assessed by using information from the 2013~2014 Korea National Health and Nutrition Examination Survey (KNHANES). Methods: A total of 6,088 persons aged 19 years and over participated in 2013~2014 KNHANES, and they were classified into three groups according to the number of household members (single-person, two-person, three-person & over). The dietary behavior, nutritional status, health-related factors and the prevalence of metabolic syndrome of the subjects were investigated with using information from the survey questionnaires of KNHANES. The nutrient intake data of the subjects were obtained by the 24-hour recall method and this was analyzed for evaluating the nutrition adequacy ratio and the index of nutritional quality. The prevalence of metabolic syndrome among the subjects, and according to the study groups, was estimated using the blood and physical measurement data of the subjects. Results: As for EQ-5D index available for all the health states generated by the EQ-5D descriptive system, the single-person household member was the lowest among all the household types. The index of nutrition quality for protein, crude fiber, calcium, phosphorus, potassium, riboflavin and vitamin C in the single-person household was lower than that of the two-person or the three-person and over households (p<0.001). The mean adequacy ratio of single-person households was significantly decreased compared with that of the other types of households (p<0.001). The prevalence of metabolic syndrome was higher in the single-person households than that in the multiple-person households (p<0.001). Conclusions: These results showed that dietary behaviors, nutrition status and health status might be influenced by the number of household members. The results from this study would be useful for improving Korean people's dietary life and health status by implementing evidence-based, specialized intervention for the members of diverse types of households.