• Korean Journal of Soil Science and Fertilizer
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• v.45 no.5
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• pp.810-816
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• 2012

In order to develop liquid fertilizer using rendering by-product, rates and velocities of degradation from rendering by-product using pig cadaver investigated under different amount of injection and time with degradation agents (KOH, NaOH, $HNO_3$ and $H_2SO_4$). The amount of residue by degradation agent of $HNO_3$ treatment method was higher than that in KOH, NaOH and $H_2SO_4$ treatment methods. The degradation velocities (K; $hr^{-1}$) of rendering by-product in KOH treatment method were higher in the order of 25% ($0.0309hr^{-1}$) > 30% ($0.0268hr^{-1}$) > 20% ($0.0142hr^{-1}$) > 15% ($0.0111hr^{-1}$) > 10% ($0.0102hr^{-1}$) of weight of rendering by-product. In all conditions, the degradation velocity of rendering by-product using $H_2SO_4$ 30% of weight of rendering by-product was rapid than that for KOH, NaOH and $HNO_3$ treatment methods. Degradation rates of rendering by-product using NaOH were similar to that of KOH and $H_2SO_4$ except for $HNO_3$ under injecting 25% and 30% of rendering by-product weight.

• Journal of Environmental Science International
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• v.12 no.12
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• pp.1315-1320
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• 2003

To obtain the residual organochlorine pesticides in the coastal environment, the methods of analysis for BHC's isomer, Kelthane, Orthocide and Endrin by GC-ECD are surveyed. The relative retention time for ${\alpha}$-BHC, ${\beta}$-BHC, (equation omitted)-BHC and $\delta$-BHC is 1.00, 1.18, 1.24, 1.31 and it's of Kelthane, Orthocide, Endrin is 1.56, 1.70, and 2.02, respectively. The BHC isomers Kelthane, Orthocide and Endrin are separated on the base line. The plate height(H) for ${\alpha}$-BHC, ${\beta}$-BHC, (equction omitted)-BHC and $\delta$-BHC is 50mm, 35mm, 32mm and 29mm, and it's of Kelthane, Orthocide, Endrin is 81mm, 68mm and 48mm, respectively. The qualified defection concentration for ${\alpha}$-BHC, ${\beta}$-BHC, (equation omitted)-BHC and $\delta$-BHC is 0.26, 0.36, 0.37 and 0.39ng/g and it's of Kelthane, Orthocide, Endrin is 0.55, 1.39 and 0.56ng/g, respectively, BHC's isomer, Kelthane, Orthocide and Endrin are not detected in soil environment on South Cheju Island. Also residual organochlorine pesticides are not detected in the sea water and sediment in the ocean environment.

• Korean Journal of Environmental Agriculture
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• v.1 no.2
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• pp.93-98
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• 1982

Effect of the application time on the persistence of IBP and isoprothiolane in rice plant was studied in the field and effects of the water depth and soil texture on their persistence were also tested as a pot experiment. When granules were applied to the rice paddy water, two fungicides were readily absorbed through the root system and rapidly translocated to the upper parts of the plant. The concentrations of two fungicides in rice plant reached to the maximum within 24 hr regardless of the application time. When applied at the maximum tillering stage, the persistence pattern of two fungicides in plant showed similar trends; that is, residue levels of two compounds declined rapidly upto 7 days after application but more slowly thereafter. When applied at the heading stage, the persistence pattern of IBP in plant was similar to the maximum tillering stage while isoprothilane was quite different; 3 ppm reached on 3rd days after application was maintained almost constant for further 25 days. There was no effect of the water depth on the persistence of two compounds in plant and IBP concentration in plant was also not affected by soil texture. However, isoprothiolane in plant was higher in sandy loam than in loam and clay loam. Isoprothiolane residues in plant were much higher than those of IBP.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.319-326
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• 1995

This study was conducted to find out the effect of natural zeolite addition on the purification of livestock farming wastewater and the application of zeolite used for purification of livestock farming wastewater on growth of sudangrass. In a semi-continuous process it was found that COD, $NH_4-N$, $NO_3-N$ and T-N contents in the effluent solution decreased with the treatment of natural zeolite. The zeolite addition was effective on the purification of livestock farming wastewater. By the results of application for sudangrass cultivation, the accumulative N-uptake contents by sudangrass were lower than that of control(35kg/10a) at early growth stage, but were higher at the late growth stage.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.187-197
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• 1984

Samples (river water, tap water, soil, sediment, fish and shellfish) collected in Downstream Area of Nakdong River were analyzed for organochlorine pesticides by G.C. equipped with electron capture detector. Residue levels of organochlorine pesticides in the river water and tap water ranged from less than detection limit (ND) to 56ppt. Total BHC concentration in the river water and tap water were found to increase in summer and decrease in winter. The variation appeared to be related to rain fall. ${\alpha}-BHC\;and\;{\beta}-BHC$ concentration in the soil were ND-3.3ppb and ND-769.7ppb, respectively. ${\alpha}-BHC\;and\;{\beta}-BHC$ concentration in the sediment were ND-2.0ppb and ND-409.9ppb, respectively. Concentration factor of total BHC in the sediment ranged from 83 to 3213. In fish, Carasssus carassius and shellfish, Anodonta woodiana(Lea) the concentration factor of ${\beta}-BHC$ and total BHC were 2,609, 435 and 3,261, 375, respectively.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.34-41
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• 1994

To better understand the allelopathic effect of sorghum(Sorghum vulgare L.), the inhibitory activities of water extracts of the stem, leaf and root, and of residues of the stem to major crops and weeds associated with them were evaluated. The allelopathic activity of sorghum plants was species specific, and depended on source and concentration. Germination, and shoot and root length of all test species were inhibited by the different concentrations of the stem extract. Among the crop species, radish showed the most inhibition, followed by wheat and rice. Maize was the least sensitive species. Of the weed species, Ipomoea triloba was most inhibited, followed by Echinochloa colona and Rottboellia cochinchinensis. The water extracts of leaves, stems, and roots significantly inhibited germination and seedling growth in E. colona and radish. The stem extract gave the greatest inhibitory effect on E. colona while all three extracts produced similar response in radish. In the greenhouse trial, sorghum stem residue placed on the soil surface as mulch significantly inhibited seedling growth in E. colona and radish, but not that in rice.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.275-282
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• 2020

As pesticide safety was extended to agricultural environments and Positive List System was carried out, Pesticide safety management in soils has become even more important. To improve pesticide safety in soils needs the degradation technology of the residues in soils and reduce plant uptake of pesticides. In this study, biochars and quicklime as the degradation methods of pesticides (azoxystrboin, procymidone and tricyclazole) were used to identify the reduction effects. The experimental methods were putting biochars and quicklimes (0, 0.5, 1.0, 2.0% per 15 cm soil weight) in soils and analyzing the pesticide residues at 0, 10, 20, 35, 50 day. To identify the reduction effects of uptake from soil to korean cabbages (roots, leave, stems) by biochar treatment, the residues in samples were analyzed. As a results, azoxystrobin (36-96%), procymidone (40-117%) and tricyclazole (26-83%) were reduced in soils when treated with 2.0% quicklime (p<0.05). There were no reduction effect in soils when treated with 1.0% or less biochar. However, the amounts of residues translocated to roots (0.11-1.62 mg/kg), leave (0.05-0.29 mg/kg), stems (0.06-0.1 mg/kg) were reduced treated with 2.0% biochar treatments. The biochar and quicklime can be applicable to agricultural field to improve pesticide safety in soils.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.6
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• pp.335-343
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• 2002

Methods of bedsoil analysis were difficult to be applied universally because use and material of bedsoil are diverse from country to country. Korean Standard Methods for Bedsoil Analysis was developed to measure the water content, water retention, and saturated hydraulic conductivity. Fifty-three samples for horticultural bedsoil and nine samples for paddy rice bedsoil in the current market were collected. Water content of bedsoil was determined using gravimetric method through $105^{\circ}C$ oven-dry for 16 hours, but different calculations between horticultural and paddy rice bedsoils were chosen according to different predominant component, plant residue or mineral. Water content percentage of horticultural bedsoil was calculated as [(weight of sample before oven-dry - weight of sample after oven-dry)/(weight of sample before oven-dry)]${\times}100$, while that of paddy rice bedsoil as [(weight of sample before oven-dry - weight of sample after oven-dry)/(weight of sample after oven-dry)]${\times}100$. Water retention was measured at water potential -0.5, -1, -3, -5, -7, -10 kPa by Sandbox method and saturated hydraulic conductivity was measured by constant head method using acryl cylinder (${\Phi}5cm{\times}L\;20cm$). By new 'Korean Standard Methods of Bedsoil Analysis', the average water content of horticultural bedsoil was obtained 46.34%(w/w) and that of paddy rice bedsoil 16.89%. For horticultural bedsoil, easily available water(EAW), water buffering capacity(WBC), and optimal matric potential(OMP) was estimated at 28.4%, 7.01%, and -5.60 kPa, respectively. Optimal moisture content was 44.41% and average saturated hydraulic conductivity for bedsoils was estimated at $28.4cm\;min^{-1}$.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1252-1257
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• 2011

Number of crop residues generated at large amount in agriculture can be utilized as substrate in methane production by anaerobic digestion. Greenhouse vegetable crop cultivation that adopting intensive agricultural system require the heating energy during winter season, meanwhile produce waste biomass source for the methane production. The purpose of this study was to investigate the methane production potential of greenhouse vegetable crop residues and to estimate material and energy yield in greenhouse system. Cucumber, tomato, and paprika as greenhouse vegetable crop were used in this study. Fallen fruit, leaf, and stem residues were collected at harvesting period from the farmhouses (Anseong, Gyeonggi, Korea) adopting an intensive greenhouse cultivation system. Also the amount of fallen vegetables and plant residues, and planting density of each vegetable crop were investigated. Chemical properties of vegetable waste biomass were determined, and theoretical methane potentials were calculated using Buswell's formula from the element analysis data. Also, BMP (Biochemical methane potential) assay was carried out for each vegetable waste biomass in mesophilic temperature ($38^{\circ}C$). Theoretical methane potential ($B_{th}$) and Ultimate methane potential ($B_u$) off stem, leaf, and fallen fruit in vegetable residues showed the range of $0.352{\sim}0.485Nm^3\;kg^{-1}VS_{added}$ and $0.136{\sim}0.354Nm^3\;kg^{-1}VS_{added}$ respectively. The biomass yields of residues of tomato, cucumber, and paprika were 28.3, 30.5, and $21.5Mg\;ha^{-1}$ respectively. The methane yields of tomato, cucumber, and paprika residues showed 645.0, 782.5, and $686.8Nm^3\;ha^{-1}$. Methane yield ($Nm^3\;ha^{-1}$) of crop residue may be highly influenced by biomass yield which is mainly affected by planting density.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.1
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• pp.1-8
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• 1972

In order to expect the effect of silica with large quantity application of current Fused calcium-magnesium phosphate on the paddy rice, there are difficulties of excess phosphorus application because of the high content of phosphate in this fertilizer. This experiment was discussed on the effect of posphate and silica absorbed by rice plant from the low concentrated fused calcium-magnesium phosphate which was fused with mixture of rock phosphate, chemical calcium oxide, magnesium oxide and silicate oxide in the furnace using coke, 1. The fusion material contained 8.9% of citric acid soluble $P_2O_5$ and 33% of soluble $SiO_2$. 2. The rice yields were increased with high significance accompanying the application levels of fused material amounts. 3. No. of grains per head, weight of 1,000 grains and percent of filled grain were caused to increase the productivity of rice plant on account of the high content of silica in straws absorbed from fusion material. The treatment of 300 kg/10a. was the highest yield among the levels of fusion material. 4. At the growing periods of rice plant, amount of absorbed phosphate was higher in the small amount treatment of fusion material until the formation period of young head, and was highest in the treatment of 300 kg/10a. leval among them but slightly desreased at 500 kg/10a. level at the harvest. Amount of absorbed silica was the same trend with phosphorus at the begining of growth period but increased rapidly from the formation period of young head to harvest in the large quantity application levels. 5. Much amount of nutrients were residued in the soil after experiment pacing with application levels. 6. The effect of silica and phosphate on rice plant can be expected with fusion material but it is necessary to decrease the phosphate content on account of the large residue of phosphate in the soil after experiment.