• Korean Journal of Soil Science and Fertilizer
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• v.48 no.4
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• pp.240-245
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• 2015

The monitoring of soil fertility changes in orchard is very important for agricultural sustainability. Field monitoring was performed to evaluate the soil chemical properties of 140 orchard (23 sites for sandy loam, 88 sites for loam, 28 sites for silt loam, and 1 site for loamy fine sand) in Gyeongnam province every 4 years from 2002 to 2014. Soil chemical properties such as pH, electrical conductivity, amount of organic matter (OM), available phosphate ($P_2O_5$), lime requirement (LR), exchangeable potassium (K), calcium (Ca), magnesium (Mg), and sodium were analyzed. The amount of OM, exchangeable K, Ca, and Mg were significantly increased as cultivation year increases. The frequency distribution within optimum range of subsoil chemical properties in 2014 was 34.3% for pH, 35.0% for OM, 17.1% for available $P_2O_5$, 22.9% for exchangeable K, 15.7% for exchangeable Ca, and 22.1% for exchangeable Mg. In addition, the available $P_2O_5$ and exchangeable calcium were excess level with portions of 69.3% and 48.6%, respectively. The soil chemical properties in the topsoil and subsoil showed that soil pH was significantly higher in sandy loam soil than those from the loam and silt loam soils. The OM, exchangeable K, Mg, and LR of loam soil were higher than those from the sandy loam soil. These results indicated that a balanced management of soil chemical properties as affected by soil texture can improve the amount of fertilizer applied for sustainable agriculture in orchard field.

• Journal of Soil and Groundwater Environment
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• v.23 no.6
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• pp.90-103
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• 2018

Although fluoride is an essential trace element, ingestion of excessive amount of fluoride could have detrimental effect on human health. Generally, the bioavailability of fluoride in soils was low, but it could be harmful to the environment depending on the soil properties. Therefore, it is necessary to understand the concentration distribution, and fate and transport characteristics of fluoride to establish a resonable management strategy for fluoride pollution. This study was conducted to evaluate nationwide fluoride distribution in soils in Korea, as well as its fate and transport characteristics. The average background concentration was 204.5 (15.3~504.8) mg/kg, which is lower than the values of foreign soils. For the three regions of different land use, the average concentration was 229.6 mg/kg in region 1, 195.7 mg/kg in region 2, and 273.4 mg/kg in region 3. The concentration of fluoride was the highest in soils from Youngnam block within tectonic structure derived from metamorphic rocks. The results of sequential extraction to access F bioavailability showed fluoride in soils mainly existed as a residual form, which suggests the bioavailability of fluoride was relatively low. Soil properties such as soil pH, CEC, and clay content were found to affect F bioavailability of soil.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.4
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• pp.221-237
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• 2005

For developing the site-specific fertilizer management strategies of crop, it is essential to know the spatial variability of soil factors and to assess their influence on the variability of crop growth and yield. In 2002 and 2003 cropping seasons within-field spatial variability of rice growth and yield was examined in relation to spatial variation of soil properties in the· two paddy fields having each area of ca. $6,600m^2$ in Suwon, Korea. The fields were managed without fertilizer or with uniform application of N, P, and K fertilizer under direct-seeded and transplanted rice. Stable soil properties such as content of clay (Clay), total nitrogen (TN), organic mater (OM), silica (Si), cation exchange capacity (CEC), and rice growth and yield were measured in each grid of $10\times10m$. The two fields showed quite similar spatial variation in soil properties, showing the smallest coefficient of variation (CV) in Clay $(7.6\%)$ and the largest in Si $(21.4\%)$. The CV of plant growth parameters measured at panicle initiation (PIS) and heading stage (HD) ranged from 6 to $38\%$, and that of rice yield ranged from 11 to $21\%$. CEC, OM, TN, and available Si showed significant correlations with rice growth and yield. Multiple linear regression model with stepwise procedure selected independent variables of N fertilizer level, climate condition and soil properties, explaining as much as $76\%$ of yield variability, of which $21.6\%$ is ascribed to soil properties. Among the soil properties, the most important soil factors causing yield spatial variability was OM, followed by Si, TN, and CEC. Boundary line response of rice yield to soil properties was represented well by Mitcherich equation (negative exponential equation) that was used to quantify the influence of soil properties on rice yield, and then the Law of the Minimum was used to identify the soil limiting factor for each grid. This boundary line approach using five stable soil properties as limiting factor explained an average of about $50\%$ of the spatial yield variability. Although the determination coefficient was not very high, an advantage of the method was that it identified clearly which soil parameter was yield limiting factor and where it was distributed in the field.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.242-247
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• 2011

Soil management for environment-friendly agriculture depends on the effects of soil microbial activities and soil fertility. To improve soil health for the upland crops, this study evaluated a relationship between soil chemical properties and soil microbial diversities at 25 sites in upland soils in Gyeongnam Province. The average nutrients in the upland soils were 1.7 times for available phosphorous, 1.4 times for exchangeable potassium and 1.5 times for exchangeable calcium higher compared to recommend concentrations in the upland soils. We found a significant positive correlation between the soil organic matter and the soil microbial biomass C (p<0.01). Contents of organic matter and dehydrogenase in the inclined piedmont soils were significantly higher than those in the other topographical soils (p<0.05). In addition, concentrations of organic matter and microbial biomass C in the loam soils were significantly higher than in the silt loam soils (p<0.05). In principal component analyses of chemical properties and microbial populations in the upland soils, our findings suggested that available phosphorous should be considered as potential factor responsible for the clear upland soils differentiation. The soil organic matter was positive correlation with Bacillus sp. and fungi, whereas soil pH was also positive correlation with Pseudomonas sp. in upland soils.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.572-577
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• 2010

Field monitoring was performed to evaluate the soil chemical properties of 31 sweet persimmon orchard soil samples every two months from April to October in 2008 at Gyeongnam Province. Soil chemical properties such as pH, organic matter, available phosphate, exchangeable potassium, exchangeable calcium, exchangeable magnesium, exchangeable sodium, ammonium nitrogen, and nitrate nitrogen were analyzed. The soil chemical properties of both top soil, and subsoil showed that soil pH was significantly increased whereas ammonium nitrogen, and nitrate nitrogen were significantly decreased. The insufficient levels of nutrients in top soil, and subsoil were higher in 69.4%, and 84.7% for pH, 63.7%, and 84.7% for organic matter compared to optimum range. Meanwhile, the excessive levels of available phosphate showed 70.2% in top soil, and 46.8% in subsoil compared to optimum range. The experimental results showed that the optimum fertilization based on soil testing was the most important thing in soil nutrients management for sweet persimmon.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.311-318
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• 1997

Chemical properties of soil(N, P, K, Ca, Na, Mg, CEC, and pH) were studied after annual additions of $NH_4NO_3$(336kg/ha N), treble superphosphate(112kg/ha P), and KCl(224kg/ha K) fertilizers in a willow(Salix spp.) bioenergy plantation. Soil samples were collected from November through December 1992 from previously established the fertilized and non-fertilized willow plantation at Tully, New York, U.S.A. in 1987. Total fertilizer additions from 1987 through 1991 were 1,680kg/ha N and 560kg/ha P and 1.120kg/ha K. Fertilization with N, P, and K resulted in no difference in total soil N content between the fertilized and non-fertilized plots, increased soil P and K, decreased base cations ($Ca^{2+}$ and $Mg^{2+}$) and soil pH, and increased soil pH with soil depth. Strong positive correlations of soil carbon to soil N, Ca, Mg, and CEC were noted. Soil C/N ratio in the study plots ranged from 9.6 to 11.2 for all treatment combinations. Significant differences in soil P, K, Ca, and pH between the fertilized and non-fertilized plots indicate that fertilization had changed chemical properties of soil in this fertilizer trial.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.5
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• pp.365-372
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• 2001

The objective of this study was to determine the effects of various kinds of composts on the change of soil physical properties and microorganism in upland soils. Field experiments were conducted in the loam and sandy loam soils, while the clay loam and sandy loam soils were used for laboratory experiments. Various kinds of composts such as poultry manure compost(PMC). cow manure compost(CMC). human excrement sludge(HES), and food industrial sludge compost(FISE) were applied annually at rates of 0, 40, and $80Mg\;ha^{-1}$ to soils grown with soybean and maize plants for 4 years during 1994 to 1997. The results of this study were as follows : Bulk density of loam soil decreased with compost application to $1.07{\sim}1.32Mg\;m^{-3}$ compared with $1.49Mg\;m^{-3}$ of control plot, while in sandy loam soil it decreased to $1.00{\sim}1.20Mg\;m^{-3}$ compared with $1.25Mg\;m^{-3}$ of control plot. Bulk density of soil was decreased according to maize cultivation compared with bare control, but soybean cultivation was similar. Population of organic material decomposing microorganisms was increased rapidly at the initial incubation stage at $25^{\circ}C$, and increased more sensitively at the loam soil than sandy loam soil. In the case of the change of microorganisms associated with nitrogen circulation, ammonia oxidizing bacteria was more at the initial incubation stage, and denitrifying bacteria was more at the initial incubation stage, and denitrifying bacteria increased until 1~4 weeks after incubation and increased more at the loam soil than sandy loam soil.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.3
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• pp.275-281
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• 2016

The aim of this study was to examine the selected soil chemical properties of paddy fields in different topographic areas to efficiently manage nutrient valances of the paddy fields in Jeonbuk Province. Three-hundred soil sampling sites in paddy fields were selected from the different topographic areas in Jeonbuk Province. The soil samples were collected every four years from 1999 to 2015. Soil pH and exchangeable K and Mg concentrations declined during the experimental periods. However, almost all the chemical properties were within the proper levels for paddy soil, except exchangeable Mg concentration. Distributed areas of the paddy fields with soil pH below 5.5 continuously increased, but the paddy fields with lower concentrations of soil organic matter and available $P_2O_5$ than the proper levels declined after 2007. In addition, the paddy fields with available $SiO_2$ below the proper concentration decreased from 83.3% of the total paddy fields studied in 1999 to 61.0% of the total fields investigated in 2015. The paddy fields with lower exchangeable K and Mg than the proper levels increased after 2003 whereas the fields with lower exchangeable Ca concentration decreased. Dominant landform of coastal and plain areas was fluvio-marine plains that was distributed in 53.7% and 40.9%, respectively. Local valley and fans was a dominant landform of mountainous and middle-mountainous areas, which was 51.8% and 67.6%, respectively. Dominant soil textures distributed in coastal and plain areas were silty loam and loam. Those in mountainous and middle-mountainous areas were sandy loam and loam, respectively. Soil pH was relatively higher in coastal area and the comparatively higher content of soil organic matter was found in costal area than other areas. The concentrations of available $P_2O_5$, exchangeable Ca, and exchangeable Mg were generally higher in mountainous, coastal, plain areas, respectively, but available $SiO_2$ and exchangeable K concentrations were not significantly different among the different topographic areas.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.4
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• pp.262-268
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• 2014

The management of soil chemical properties is very important to sustainable agriculture of many horticultural crops, including cucumber. This study was conducted to find the optimal soil properties of environmentally friendly agriculture in controlled horticulture. Soil chemical properties of 267 samples were collected from soil in Chungnam Province. The average of pH, EC, OM, available $P_2O_5$, exchangeable K, Ca, and Mg was 6.1, $5.38dS\;m^{-1}$, $34g\;kg^{-1}$, $1,321mg\;kg^{-1}$, $1.50cmol_c\;kg{-1}$, $10.3cmol_c\;kg{-1}$, and $3.4cmol_c\;kg{-1}$, respectively. The organic matter content in silty clay loam was significantly higher than in the other soil textures, whereas the pH, EC, exchangeable K, and Mg in loamy fine sand showed significantly lower among soil textures. The EC value and exchangeable Mg concentration were highest in mountain foot-slope soils. The frequency distribution within optimum range of soil chemical properties was 26.2%, 30.3%, 2.3%, 3.8%, 3.4%, and 6.7% for pH, OM, available $P_2O_5$, exchangeable K, Ca, and Mg, respectively. Especially, excessive portion of available $P_2O_5$ and exchangeable Ca were 94.0% and 94.4%, respectively. The EC value and organic matter content of soil samples were positive correlation with all chemical properties except soil pH. In principle component analysis of chemical properties in soil samples, the percentage of variance explained by PC 1 was 52.2%, while PC 2 explained 21.3% of the variance, for a cumulative total of 73.5%. In conclusion, these results are considered to improve soil nutrient management for sustainable controlled horticulture.

• 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.