• Korean Journal of Soil Science and Fertilizer
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• v.50 no.2
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• pp.115-126
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• 2017

There is an increasing concern over arsenic (As) contamination in rice. This study was conducted to develope a prediction model for As uptake by rice based on the physico-chemical properties of soil. Soil and brown rice samples were collected from 46 sites in paddy fields near three different areas of closed mines and industrial complexes. Total As concentration, soil pH, Al oxide, available phosphorus (avail-P), organic matter (OM) content, and clay content in the soil samples were determined. Also, 1.0 N HCl, 1.0 M $NH_4NO_3$, 0.01 M $Ca(NO_3)_2$, and Mehlich 3 extractable-As in the soils were measured as phytoavailable As concentration in soil. Total As concentration in brown rice samples was also determined. Relationships among As concentrations in brown rice, total As concentrations in soils, and selected soil properties were as follows: As concentration in brown rice was negatively correlated with soil pH value, where as it was positively correlated with Al oxide concentration, avail-P concentration, and OM content in soil. In addition, the concentration of As in brown rice was statistically correlated only with 1.0 N HCl-extractable As in soil. Also, using multiple stepwise regression analysis, a modelling equation was created to predict As concentration in brown rice as affected by selected soil properties including soil As concentration. Prediction of As uptake by rice was delineated by the model [As in brown rice = 0.352 + $0.00109^*$ HCl extractable As in soil + $0.00002^*$ Al oxide + $0.0097^*$ OM + $0.00061^*$ avail-P - $0.0332^*$ soil pH] ($R=0.714^{***}$). The concentrations of As in brown rice estimated by the modelling equation were statistically acceptable because normalized mean error (NME) and normalized root mean square error (NRMSE) values were -0.055 and 0.2229, respectively, when compared with measured As concentration in the plant.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1126-1135
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• 2012

In order to produce high-quality fermenting composts, bacteria strains with high activities of extracellular enzymes (cellulase, chitinase, amylase, protease and lipase) were isolated from the soils in 6 provinces of Korea, and characterized by 16S rRNA gene sequence analysis and properties. The selected 7 stains inoculated to livestock manure for 2' fermenting time, and experimental treatment divided into 3 groups, B1, B2 and B3, according to microbial activity and enzyme type. Our results showed that microbe applications (B1, B2 and B3) can increase (p<0.05) both rhizomes (17-38%) and enzyme activities (50-81%) in compost after fermenting time, respectively, compared to non-microbe treatment (control). The microbe application also decreased significantly (p<0.05) the $NH_3$ and $H_2S$ gas contents 13.4 and 27.3% compared with control, and the Propionic acid and Butyric acid gas contents 14.5 and 19.6%, respectively, as compared to the control. The microbial degradation rate (%) of pesticides and heavy metals increased significantly (p<0.05) after fermenting time, respectively, as compared to the control. Especially, microbe applications were more effective in total rhizomes yields and bioactivities than non-microbe treatment. Thus the results of this study could help in development of potential bioinoculants and composting techniques that maybe suitable for crop production, and protectable for earth environment under various conditions.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.4
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• pp.259-274
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• 2017

To get some informations for sustainable paddy use, the productivities of soils with two years of cropping systems were estimated through pot experiment using two pretreated groups of not autoclaved 'natural'- and 'autoclaved'-soils without any fertilization. And then the relationship between the productivities, called yield potentials, and the characteristics of soils as affected by cropping systems, such as rice-rice (R-R), ricebarley-rice-barley (R-B-R-B), rice-barley-rice-wheat (R-B-R-W), soybean-barley-soybean-barley (S-B-S-B), of which barley and wheat were composted at a level of $10MT\;ha^{-1}$, and S-B-S-B without compost, was analyzed. These treatments were established in mid-mountainous loam paddy, which contained exchangeable Ca of $11.8cmol_c\;kg^{-1}$, located at the altitude of 285 m above sea level in Sangju of Korea. Crops for the estimation of soil productivity were rice cv. 'Seolemi' and soybean cv. 'Chamol'. As a result, under the natural soils condition, rice grain and straw were highly produced in composted S-B-S-B soils (p < 0.05) and lowly in R-R soils (p < 0.05). While soybean grain and stem were higher in R-R soils (p < 0.05) than other soils which not significantly different each other. In case of autoclaved soils, the yield potentials of rice and soybean were high together in either composted R-B-R-B/W or S-B-S-B soils compared to R-R and uncomposted S-B-S-B soils (p < 0.05). In especial, these yield potentials under the natural soils condition were commonly influenced by soil porosity showing negative correlation for rice (p < 0.01); positive for soybean (p < 0.05). And the porosity possibly reversed even the symbiotic contribution of indigenous Bradyrhizobium japonicum for soybean. Under autoclaved soils condition the potentials of rice and soybean showed negative correlations with soil C:N ratio (p < 0.05) similarly to the case of rice in the natural soils.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.214-221
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• 2009

Denitrification efficiency associated with incorporation of the diffrent carbon substrates with the anaerobic sludge was investigated. For this each kinetic constant such as methane reaction and specific denitrification rate (SDNR) were determined in each treated sludge. In the pure methanogenesis, the specific methanogenesis activity (SMA) value was the highest at $0.76COD/g\;VSS{\cdot}day$ when the acetate was incorporated with the anaerobic sludge which has already been adapted at consistent C/N ratio 5 for reatively higher denitrifier population. The anaerobic dinitrificaition and methanogenesis reaction were dependent on both the types of carbon substrate and sludge showing the higher denitrificaition reaction constant at $1.96hr^{-1}$ with incorporation of acetate with the anaerobic sludge at C/N ratio 5 than any other carbon sources examined. When the glucose was introduced as electron donor for the anaerobic sludge adapted with different carbon substrates the SDNR showed the highest value with the sludge adapted to glucose followed by the sludge adapted to piggery sludge and acetate.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.227-232
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• 2009

Land application of animal manure, such as pig slurry(PS), has been considered as valuable organic source to supply necessary nutrients for crop growth. On the other hand, little information is available on the effect of consecutive application of PS on agricultural soils. This study was conducted to evaluate the influence on change in soil chemical properties and yield of Chinese cabbage in soils amended with slurry composting and bio-filtration pig slurry (SCB) for four consecutive crop cultivations (2007-2008). Among total application rates required, a basal fertilizer (35%) was applied with SCB or chemical fertilizer (CF). The CF was applied as a side dressing was applied in all treatments. There was no significant effect of SCB and CF on Chinese cabbage yield during four cropping seasons. In addition, soluble sugar, vitamin C contents and yields of Chinese cabbage between SCB and CF did not show statistically significant difference. During the experiment, soil chemical properties between SCB and CF treatment showed similar pattern, however, the contents of exchangeable sodium (Na) in soil has been increased (P<0.05) since the second cropping season because of higher Na contents in SCB. Therefore, the use of SCB as a substitute of CF is available for growth and yield of chinese cabbage while its long-term application might leads to an accumulation of Na in soil.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.6
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• pp.367-375
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• 2003

The aim of this study was to investigate the soil physical properties and the traction characteristics of paddy field before tillage by a computer simulation. Soil physical properties, such as soil moisture content, bulk density, soil hardness, and soil texture were measured in the twelve rice production area. Mathematical model based on dimensional analysis which include soil physical properties and vehicle factors was used for the computer simulation. Most of the soil texture of the investigated area was silty loam, loam and silty clay loam. Soil moisture content ranged between 20 and 40% mostly. Soil bulk density was in the range of 1,500 to $1,700kg\;m^{-3}$. Soil hardness ranged between 2 to $12kg\;cm^{-2}$ mostly. Soil hardness incorporates the effects of many soil physical properties such as moisture content, texture and bulk density, and so the range of soil hardness was greater than that of any other physical properties. The predicted net traction was in the range of 70 to 1,500 kgf depending on the area, but it was above 1,000 kgf for most of the investigated area. Thus it was concluded that 50 HP tractor can pull the four row moldboard plow considering the conventional tillage depth and width. But for the soft soil area such as Andong and Namyang, tractor itself may have mobility problem and show high slip during plowing operation.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.199-204
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• 2014

We conducted a short-term incubation experiment in order to understand the effect of the salinity of reclaimed coastal soils on nitrogen mineralization of livestock manure compost (LMC). Two soils with the same soil texture but different EC levels were collected from the same field. These samples were treated with 0%, 1%, 2%, and 3% of LMC by weight basis and incubated at $25^{\circ}C$ to observe changes in inorganic N contents, pH, and dehydrogenase activity with respect to time. As a result, regardless of the soil EC level, as the LMC increased, the total content of the inorganic N ($NH_4{^+}+NO_3{^-}$) increased. Difference in the soil EC level did not affect N mineralization of LMC greatly. The soil EC had negligible effect on the dehydrgenase activity as with the case of inorganic nitrogen. The $NH_4{^+}$ contents remained very low throughout the experimental period starting from the first week of incubation. We believe this is due to the high pH level (pH 7.9 and pH 8.3) of the original soils leading to ammonia volatilization. On the other hand the $NO_3{^-}$ content maintained high level as the LMC treatment level increased and reached maximum at the third week. The pH of the soil during incubation period decreased as the $NO_3{^-}$ contents increased and increased slightly after three weeks. The rise of pH level is believed to be from the $NO_3{^-}$ absorption for immobilization by microbes. In conclusion, the high soil $EC_{1:5}$ level of $12dS\;m^{-1}$ conducted in this experiment did not affect the growth in terms of soil microbes involved in N mineralization of LMC.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.379-384
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• 2009

This study was carried out to understand the national and regional distribution of the biomass resources produced in Korea annually via establishing database (DB) and distribution maps of biomass resources data including as livestock manures, food wastes and agricultural by-product. The information of the annual production of each biomass resources was obtained from Ministry for Food, Agriculture, Forestry and Fisheries (MIFAFF), Ministry of Environment (MOE) and National Statistical Office (NSO). Based on biomass resources data, we established database architecture table about livestock manures and food wastes. The distribution maps for the total amount of manures produced from each livestock animal were built up in both national and regional scales and used for analysis of the space-based and time-based distribution of the manure resources. Distribution maps for food wastes and agricultural by-product were also produced, respectively. It was shown that the analysis through resource mapping can be used to identify the sources of collectable biomass feasibly determining suitable region for establishment of a biomass-energy production. The biomass distribution maps graphically provide the information regarding biomass resources to policy-makers, farmers, general users and it was expected to be utilized for policy-making of environmental-friendly agriculture and bio-energy.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.186-191
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• 2012

Experiments were conducted to investigate the effect of fertigation (fertilizer-added irrigation) on soil EC (electrical conductivity), nitrogen and calcium content in soil, vine growth and fruit yield of oriental melon (Cucumis melo L. var. makuwa Mak.). Soil EC was increased with the frequency of fertigation (Yamazaki's solution for melon, 900 L/1,000 plants, each time) up to $0.8dS{\cdot}m^{-1}$ as compared to that of conventional irrigation ($0.2dS{\cdot}m^{-1}$). Ca content in soil also increased in fertigation fields. Vine dry weigh (20 days after planting) was significantly increased in fertigation plot. Markedly increases in marketable fruit yield and lower rate of off-shape fruit were recorded with the increase in fertigation frequency. Mean fruit weight and soluble solids contents ($^0Brix$) in fruit were not affected by fertigation. Fresh weight loss during storage was significantly higher in fruits harvested from 2 times fertigation (09:00 and 18:00) plot than conventional irrigation and the 1 time fertigation ones.

• Journal of Bio-Environment Control
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• v.21 no.1
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• pp.57-65
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• 2012

Fertilization is essential to seedling production in nursery culture, but excessive fertilization can contaminate surface and ground water around the nursery. The objective of this study was to find optimal fertilization practice of container seedling production for reducing soil and water contamination around the nursery without compromising seedling quality. This study was conducted to investigate chemical properties of the growth medium, growth performance, chlorophyll fluorescence, and chlorophyll contents of larch ($Larix$ $kaempferi$) growing under three different fertilization treatments (Constant rate, Three stage rate, and Exponential rate fertilization). Root collar diameter and height of larch were not significantly different among treatments even though the nutrient supply of the exponential treatment was half that of the constant and three stage treatments. Chemical properties of the growth medium showed the same trends as root collar diameter and height. The total biomass and seedling quality index (SQI) were higher at Constant than at other treatments, but both SQI of Constant and Exponential were not significantly different. Photochemical efficiency and chlorophyll contents were lower at Exponential than at other treatments, but not significantly different among treatments. Therefore, Exponential fertilization which is 50% fertilizer of other treatments would maximize seedling growth and minimize nutrient loss.