• Korean Journal of Soil Science and Fertilizer
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• v.40 no.2
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• pp.109-113
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• 2007

In order to establish the fertilization and soil management method in Gyehwa reclaimed tidal land, we investigated soil property and actual farming condition. Soil properties of 100 field paddy soil and farming surveys of 177 farm households were conducted. Average of effective soil depth was 17.8 cm, which was very smaller than the optimum level 50 cm. The hardness and bulk density of subsoil were $12.40kg\;cm^{-2}$ and $1.59g\;cm^{-3}$, respectively. These results showed that soil physical condition of Gyehwa reclaimed tidal land was very poor. Soil salinity ranged from 0.03 to 0.12%, and average of pH was 6.0, which implied that desalinization of Gyehwa reclaimed tidal land was progressed. However, soil nutrients in Gyehwa reclaimed tidal land were very unbalanced conditions as following, available phosphate $58mg\;kg^{-1}$, available silicate $85mg\;kg^{-1}$, cation exchangeable capacity $7.4cmolc\;kg^{-1}$ and organic matter $8.6g\;kg^{-1}$. On the farm household in Gyehwa reclaimed tidal land, fertilization amounts were $200-54-61(N-P_2O_5-K_2O)kg\;ha^{-1}$ They mainly practiced spring tillage(84%) rather than autumn tillage(16%), and only 14% of them applied rice straw annually in the paddy soil.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.86-92
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• 2012

To promote the practical use of livestock manure compost (LC) for paddy rice cultivation, the fertilization efficiency of nutrients in LCs was investigated compared to that of chemical fertilizer. This experiment was conducted at rice field in Hwaseong, Korea, with 6 treatments by each of 3 kinds of tested LCs, cattle manure compost (CaC), swine manure compost (SwC) and chicken manure compost (ChC). The treatments consisted of 3 application levels of LCs and 3 chemical fertilizer treatments having the same application levels with LCs. $NH_4$-N content in soil became higher according to the increase in the urea application rate, while it became lower in LC plots than in urea plots, and statistically had no significant difference among LC plots. There was a close relationship between phosphate fertilization rate and the increment of soil available phosphate content after experiment resulting y = 0.1788x - 6.169 ($R^2=0.9425$) when applied fused superphosphate fertilizer, and y = 0.0662x - 2.689 ($R^2=0.9315$) when applied LC at the equivalent rates to phosphate input (x: phosphate application rate, kg $ha^{-1}$, y: increment in soil available phosphate content, mg $kg^{-1}$). And from these two equations, the correlation on the phosphate application rate between fused superphosphate fertilizer and LC could be obtained as y = 2.7056x - 52.492 (x: $P_2O_5$ application rate of fused superphosphate, kg $ha^{-1}$, y: $P_2O_5$ application rate of LC, kg $ha^{-1}$). Plant height, number of tillers, nutrients uptake by rice, and rice yield showed higher levels in N 100% and N 150% application plots of chemical fertilizers, while every LC plots exhibited lower values and no significant difference among them. Relative nitrogen fertilization efficiencies of LCs compared to urea was 12.3% for CaC, 8.8 for SwC and 24.6 for ChC, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.1
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• pp.25-30
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• 1993

It is common that in the vegetable cultivation areas, the farmers tend to continue the heavy fertilization to maximize the crop yields in short term. This results in the accumulation of fertilizer elements in the soil and increase in the electrical conductivity of soil. Disregarding these, farmers continue to apply heavy doses of fertilizers. A field experiment was conducted to find out on such a soil whether fertilizer application taking the quantity of nutrients accumulated in the soil into account would save the fertilizer without losing the yield of crop, using Chinese cabbage and spinach as test crops. The findings of the experiment is summarized as following. 1. The yield of Chinese cabbage was not affected by reduction of $19kg\;P_2O_5/10a$ and $7kg\;K_2O/10a$ as compared to farmers doses, and in case of spinach the yield rather was increased under the reduction of $22kg\;P_2O_5/10a$ and $22kg\;K_2O/10a$. 2. The reduction of fertilizers according to plant nutrient status of soils did not affect the inorganic nutrient contents of the crops significantly, in both Chinese cabbage and spinach. 3. A trend was observed that the reduction in the P and K fertilizers application would shorten the storage period of Chinese cabbage. 4. The reduction in P and K fertilizers application resulted in the reduction in available P, exchangeable K, EC and $NO_3-N$ in the soil after the harvest of the crops.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.3
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• pp.145-153
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• 2003

The average values of soil chemical concentration in investigation regions were pH 5.93, $25.9g\;kg^{-1}$ of organic matter, $742mg\;kg^{-1}$ of available phosphate and $44.7mg\;kg^{-1}$ of nitrate nitrogen. The number of mycorrhizal spores analysed from 1g of soil sample was 12.1 for onion, 11.7 for garlic and 10.1 for red pepper. In fractionation of soil texture, clay and silty clay showed more than 15 spores per 1g of soil. There was no relationship between spore density and soil nutrition of pH, organic matter, $NO_3-N$ and Av. $P_2O_5$. However, the number of spores was constant level independent on the concentration of soil nutrition. Spores identified in this study are as follows: Glomus clarum, Glomus intraradices, Glomus etunicatum, Gigaspora rosea and Gigaspora margarita.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.92-97
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• 1994

An attempt was made to provide the most resonable fertilizer recommendation for sesame and peanut crops based on soil analytical data and yield response to the NPK fertilizer application, which were obtained from field experiments conducted during 1970 to 1993. 1. According to the analytical data of sesame and peanut soils obtained in 1985~1993, the contents of organic matter, available $P_2O_5$, exchangeable K, Ca and Mg were increased in sesame soils, but the those components were decreased in peanut soils. 2. The yield index of the plot without N, $P_2O_5$ and $K_2O$ fertilizer were 81-84, 84~92 and 81~92, respectively, as the yield of NPK plot was regarded as 100. 3. Linear or quadratic equations derived from the relationship between soil analysis data and fertilizer application rates were proposed for NPK recommendation. The parameters of soil analysis used in the equations for N, P and K were organic matter, available $P_2O_5$ and exchangeable K, respectively. 4. Revised fertilizer recommendation based on the soil chemical status enable to save the fertilizer application of sesame and peanut soils. The amounts of saved NPK fertilizers were 5.1kg N/10a(increase in 2.8kg N/10a for peanut), 0.9~2.9kg $P_2O_5/10a$, and 1.7~5.8kg $K_2O$/10a.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.147-152
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• 2010

The investigations were conducted to improve the fertilizer use in upland soil on the different topographies, and crops at 163 upland fields located in the parts of Gyengsangbuk-do area. The soil distribution was based on crops, and topographiese. Soils from these fields were analyzed for pH, organic mater, available phosphorus ($P_2O_5$), exchangeable potassium, calcium and magnesium, and found to have pH5.9, organic mater 23.2 g $kg^{-1}$, $P_2O_5$ 549 mg $kg^{-1}$, exchangeable potassium, calcium and magnesium were 0.9, 5.6, and 2.3 $cmol^+\;kg^{-1}$, respectively. The excessive distribution percent of soil samples for crops were higher than the optimum range in $P_2O_5$, and exchangeable potassium. The content of organic matter, $P_2O_5$, exchangeable potassium, calcium, and magnesium were increased with the decreasing slope. The major chemical components in fans topographies were 28.4 g $kg^{-1}$ for organic matter, 700 mg $kg^{-1}$ for $P_2O_5$, and 1.0 $cmol_c\;kg^{-1}$ for exchangeable potassium relatively higher in comparison with other topographies. The content of $P_2O_5$ were lower in diluvium, and hilly areas than other topographies. The soil of red pepper was more influenced by the amount of applied fertility than the slope, and topographies, On the other hand the crops like soybean and sesame, were more affected by the slope, and topographies.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.234-235
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• 2006

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.39-47
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• 2002

This study was carried out in order to produce useful material for the forest multiple use and forest protection by soil physico-chemical analysis of studied area in Mt. Palgong. The results of soil physico-chemical analysis and statistical analysis represented as following 2 points. 1. Soil depth was in the range of average 61.1 cm and soil texture was loamy sand and sandy loam except Donghwasa area. The part of solid phase and gaseous phase were higher than other areas, but liquid phase was less in verse. Soil water content was in an average 49.5%, penetrability was average $1.95{\times}E^{-2}cm/sec$ and the average of soil hardness was $1.64Kg/cm^2$. This data showed that soil water content, penetrability and soil hardness were good at Mt. Palgong forest soils. 2. Soil pH was the range of 3.4 to 6.0, organic carbon content was 2.8% that is nearly mean of the Korea brown forest soils, total N content is somewhat smaller than that of other places, and total average C/N ratios was 13.9. Average available $P_2O_5$ concentration was 5.05 mg/kg that is lower than that of any others. The concentration of available P of coniferous forests is higher than that of deciduous forests. Exchangeable cations content is similar to those of the Korea brown forest soil and the order of the cation content extent is $Ca^{2+}$ > $Mg^{2+}$ > $Na^+$ > $K^+$.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.384-390
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• 2003

Removal of phosphate from soil by leaching, runoff, and plant uptake is strongly influenced by the content and absorption characteristics of P in soil. In this study the relationships between water soluble phosphate and phosphate retention capacity of the soil was investigated. Water soluble and available phosphate, and phosphate absorption characteristics of 35 paddy soils were measured during incubation at $25^{\circ}C$. Water soluble phosphate content was highly correlated with available phosphate content, phosphorus absorption capacity (PAC), and phosphate absorbed (PS) in air-dried and wet soils. The most significant relationship was found between water soluble phosphate and the ratio of available phosphate and phosphate sorbed, and the relationship $0.01M\;CaCl_2-P=0.0828$ (Av. $P_2O_5/PS$)+0.0374 could be suggested for the estimation of water soluble phosphate from soil phosphorus characteristics.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.211-214
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• 1998

Changes in physico-chemical properties and major nutrient contents were investigated in the soil of paddy fields during fallow period. Weed vegetation change in the fallow paddy fields was also examined. As the fallow period became longer, organic matter content in the paddy soil has gradually increased. Soil pH of the paddy fields has not changed until three years of fallow period and thereafter slightly increased. Cation exchange capacity of the paddy soil, and exchangeable N, K, Ca and Mg contents in the soil tended to decrease until three years of fallow period and then increase with the prolonged fallow period. As the fallow period became longer, available $P_2O_5$ content in the paddy soil has continuously decreased. Available $SiO_2$ content in the paddy soil has not changed until three years of fallow period and thereafter increased. The vegetation in the fallow paddy fields have mostly been occupied by the weeds of the Gramineae, Cyperaceae, and Compositae. As the fallow period became longer, the weeds of the Polygonaceae and Juncaceae have increased, whereas the weeds of the Leguminosae, Commelinaceae, Pontederiaceae, and Onagraceae have gradually disappeared. However, the weeds of the Gramineae and Cyperaceae have always been dominant in the paddy fields during the fallow paddy period.