• Korean Journal of Soil Science and Fertilizer
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• v.41 no.1
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• pp.65-73
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• 2008

Because main barley straw management is changing these days from off-fields to burning that may relate to air quality concerning the global warming, this study was conducted to investigate the effects of barley-straw management practices on greenhouse gas emissions during rice cultivation in rice-barley double cropping system. The treatments were barley straw burning, off-field usage of barley straw and incorporation of barley straw in paddy fields. Laboratory experiment showed that burning of barley straw at the rate of $4.5Mg\;ha^{-1}$ emitted GHGs in the amounts of 4,607, 19.5, and $0.9kg\;ha^{-1}$ of $CO_2$, $CH_4$, and $N_2O$, respectively. During the rice cultivation of the rice-barley double cropping system, the highest GHG emission by evaluated close-static chamber method was observed from the soil incorporation of barley straw with 387 and $1.0kg\;ha^{-1}$ of $CH_4$ and $N_2O$, respectively. The GHGs emissions from the barley straw burning and off-field usage treatments were 233 and $160kg\;ha^{-1}$ for $CH_4$ and 0.80 and $0.79kg\;ha^{-1}$ for $N_2O$, respectively. The barley straw burning treatment showed the greatest GHGs emission among barley straw management practices in rice-barley double cropping system when considering GHGs emissions both during burning and from paddy fields during the cropping seasons. As a result, the GHGs emissions recorded in the barley straw incorporation to soil and off-field usage treatments were 22.4 and 66.8%, respectively, less than sum of GHGs emissions from the burning of barley straw and from paddy fields during rice cultivation.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.51-56
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• 2015

The objective of this study was to evaluate the effect of silicate fertilizer on growth, physiology and abiotic stress tolerance of Chinese cabbage seedlings. Five silicate concentrations (8, 16, 32, 64, and 128mM) and control (non-treatment) were applied to Chinese cabbage seedlings twice a week. Three weeks after application of silicate treatment, seedlings were used for treating abiotic stresses and were assessed for growth and physiological characteristics. Growth parameters significantly increased in 8, 16, and 32mM treatments except 64 and 128mM. Total root surface area, total root length, and number of root tips increased in 8, 16 and 32mM treatments, but they decreased in treated seedlings with 64 and 128mM of silicate. The highest growth parameters and root morphology were observed in 8mM treatment. As for the effect on the seedling physiology, transpiration rates decreased while stomatal diffusive resistance increased to increasing silicate concentration. The application of silicate reduced the electrical conductivity, heating and chilling injury index at high and low temperatures. Silicate enhanced drought tolerance of Chinese seedlings by delaying the starting time of wilting point. The starting time of wilting point in the control was 3 days after discontinuation of irrigation, while in the 8, 64 and 128mM of silicate treatments were 4 days, and the 16 and 32mM treatments were 5 days. All plants were wilted after 5 days in control without irrigation whereas it showed in 8mM treatment after 6 days, in 16, 32, 64, 128mM treatments after 7 days.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.1
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• pp.24-31
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• 2000

This study was conducted to determine the effect of soil physical characteristics on rhizome rot incidence of platycodon. Sampling sites were Keochang 4, Kimhae 7, Haman 6, Chinju 6 and Koseong 3 fields in Kyongnam province and Hongcheon 6 fields in Kangwon province. The root disease incidence rate was correlated with soil depth Y=-0.747X+88.19($R^2=0.394^{***}$), soil hardness Y=4.36X+8.93($R^2=0.201^*$), bulk density Y=104.7X-80.99($R^2=0.295^{**}$), clay content Y=1.24X+14.14($R^2=0.196^*$), porosity Y=-3.11X+215.9($R^2=0.220^*$) and silt content Y=-0.75X+67.85($R^2=0.178^*$). The yield was correlated with soil depth Y=0.263X+0.971($R^2=0.105^*$), clay content Y=-0.688X+32.74($R^2=0.158^*$), porosity Y=1.974X-93.19($R^2=0.231^{**}$) and silt content Y=53.05X-108.65($R^2=0.232^*$), The optimum cultivated land of perennial platycodon was soil depth over 1m, soil hardness under $5kg\;cm^{-2}$, bulk density $1.0Mg\;m^{-3}$, moisture content 13~17%. clay content 5~10%, porosity 58~63%, silt content 38~64% and soil texture of silt loam.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.100-108
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• 2000

High sodium contents in food-waste compost(FWC) is the greatest limitation to recycle it to arable lands in Korea. The effects of the FWC application to paddy soil on the growth of rice plants, cationic balance in plants, and the sodicity of soil have been studied in pot trials. The effects of FWC application were compared with those of NaCl compound and swine manure compost(SMC) application. $Na_2O$ contents of FWC were high as 2.2%. Immediately after transplanting, rice plants in three treatments showed severe wilting in the order of 40Mg FWC $ha^{-1}$ > NPK+900kg $NaClha^{-1}$ > 20Mg FWC $ha^{-1}$. The high EC value and volatile acid contents of soil solution were regarded as the cause of severe wilting of young rice plants. Increase of NaCl application rate upto $900kgha^{-1}$ showed no significant reduction of dry matter yield at harvesting stage. Regardless of application rates FWC reduced the dry matter yield at harvesting stage, while SMC increased it with increase of application rates upto $40Mgha^{-1}$. In NPK+NaCl and FWC treatments, Na contents and equivalent ratio in plants increased linearly with increase of Na application rates. Between Na and K equivalent ratio negative correlation with high significance was shown. In contrast to much difference of Na, K, and Na/K equivalent ratio among treatments, little difference of Na+K indicated the physiological substitution of Na for K in rice plants. Na use efficiency in NPK+NaCl and FWC treatments showed 12-22%.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.92-99
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• 2000

To compare the effect of food waste compost(FWC) application on the sodicity of paddy and upland soil, laboratory experiment was conducted. Six kinds of FWC made of various mixing ratio of food waste and pig slurry as raw material were applied to paddy soil under submerged condition and to upland soil in field water capacity, and were kept at $25^{\circ}C$ under laboratory incubation. The higher the mixing ratio of food waste on making FWC, the higher the FWC showed Na content and EC. Mineralized ratio of cations in FWC during incubation showed no difference between paddy and upland soil. It was high in the order of Na>K>Mg>Ca as 99, 94, 71, and 71%, respectively. NaCl contents of FWC applied to soils against SAR and ESP were fitted well to first linear regression with extremely high significance($R^2=0.99$). Increasing rate of SAR and ESP was higher in upland soil than paddy soil by 2.3 times. The difference was considered to be caused by dilution effect which was exerted by the application of more soil to water ratio to paddy soil than to upland soil on SAR analysis in consideration of cultivating condition. The calculated values of $([Ca^{2+}+Mg^{2+}]/2)^{1/2}$ used as a denominator on SAR calculation showed a little difference among FWC treatments by 2.1~2.4, while [$Na^+$] used as a numerator showed much variance by 3.1~9.5. Therefore, as a parameter for the assessment of FWC quality affecting soil sodicity, the use of only Na content in FWC was proposed without regarding Ca and Mg contents. Soil Ex. Na contents showed extremely high correlation($R^2=0.99$) with ESP. Moreover, because the former can be more easily determined than the latter, soil Ex. Na content was proposed as a new sodicity index.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.259-267
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• 2006

Hydraulic conductivity is the rate of water flux on hydraulic gradient. The van Genuchten Mualem (VGM) model is frequently used for describing unsaturated state of soils, that is composed with the function of soil water potential and soil water content and requests various parameters. This study is to get the value of VGM parameters used Rosetta computer program based on neural network analysis method and to calculate VGM parameters. VGM parameters included Ko(effective saturated hydraulic conductivity), ${\theta}r$(residual soil water content), ${\theta}s$(saturated soil water content), L, n and m. The unsaturated hydraulic conductivity at 10 kPa was calculated by using Rosetta program. Unsaturated hydraulic conductivities of 17 soil series at 1, 3, 5, 7 kPa were also obtained by applying saturated hydraulic conductivity by disk tension infiltrometer based on Gardner and Wooding's equation. Water flow at the water potential of 3 kPa was very low except Namgye, Hagog, Baegsan, Sangju, Seogcheon, Yesan soil series. Unsaturated hydraulic conductivity at 1 kPa showed the highest value for Samgag soil series and was in order of Yesan, Hwabong, Hagog and Baegsan soil series. Those of Gacheon, Seocheon and Ugog soil series were very low. When the value by VGM was compared with the value by disc tension infiltrometer, there was a tendency with exponential function to soils without gravel but there was no tendency to soils including gravel. Conclusively, it would be limited that VGM model for unsaturated hydraulic conductivity analysis applies to Korean agricultural land including gravel and having steep slope, shallow soil depth.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.3-15
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• 1997

Iron oxide compounds in 8 selected Cheju Island soil samples have been analized by X-ray fluorescence spectrometer(XRF), X-ray diffractometry(XRD), selected chemical techniques, and $M{\ddot{o}}ssbauer$ spectroscopy. The result of this analysis by XRF shows that the rate of quantity of $Fe_2O_3$ in 8 soil samples was from 8.03wt.%(Daejeong paddy soil) to 18.21wt.%(Songag soils). Songag, Heugag and Gueom soils were detected to have lower peaks of intensity of hematite by XRD. In addition, these soils were not detected to have hematite and goethite peaks. Ferrihydrite, which is a short-range-order mineral commonly present in volcanic ash soil, was not detected by XRD due to low concentration and/or poor cristallinity. Ferrihydrite contents estimated from Feo values were 8.8~35.2g/kg for volcanic ash soils and 0.85g/kg for the Daejeong soil. Most of the soil samples represented by the paramagnetic $Fe^{3+}$ doublet obtained from $M{\ddot{o}}ssbauer$ spectra at room temperature and 18K were considered to arise from the presence of ferrihydrite, superparamagnetic goethite, and silicate minerals. Also the paramagnetic $Fe^{2+}$ doublets are attributable to primary minerals such as olivine, illite, chlorite, augite, biotite, and hornblende. Goethite and hematite were identified as the dominant crystalline iron oxides in these soils from $M{\ddot{o}}ssbauer$ spectra obtained at room temperature and 18K. All the soil samples exhibited strong superparamagnetic relaxation. Collapse of the $M{\ddot{o}}ssbauer$ magnetic hyperfine splitting at room temperature was due to the small size(${\sim}180{\AA}$) of the oxide particles and/or Al-subsituted goethite.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.1
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• pp.47-58
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• 2002

Much of the plastic film house soils in the southern part of the Korean peninsula are managed using a upland-paddy rotation culture system (hereafter, RS) to prevent salt accumulation in soil. However, information on the effects of RS on soil properties and environmental conservation is limited. In order to determine the effects of RS on soil properties, 22 fields under RS and 20 fields under a non-rotation system (hereafter, NRS) in plastic film houses were selected in Chinju, in southern Korea, and the P distribution characteristics were investigated, including the chemical properties. The RS contributed to the removal of water-soluble salts in the surface layer and to the redistribution of organic matter evenly in the soil profile. In the AP horizon, available phosphorus levels were $1,611mg\;kg^{-1}$ in RS and $1,789mg\;kg^{-1}$ in NRS, which markedly exceeds the optimum range for plant cultivation. Total P was lower in RS (average $4,593mg\;kg^{-1}$) than in NRS (average $5,440mg\;kg^{-1}$) and this decrease was taken to be an effect of RS. Inorganic P was the predominant form of P in both systems, followed by organic P and residual P. A soil profile showed that total and inorganic P concentrations decreased with depth in both systems. However, organic P increased withdepth in RS, which was in contrast to that noted in NRS. The increase in organic P with depth in RS implied that organically rather than inorganically derived phosphate moved through the soil. The concentrations of water-soluble P, Ca-P and Al-P were higher in NRS than in RS soil profiles, but the Fe-P concentration was higher in RS than in NRS, which might be affected by the anaerobic conditions found in paddy soils. In both systems, the Al-P form of extractable P predominated in the surface layer, followed by Ca-P, Fe-P and water-soluble P. With increasing depth, the composition rate of Ca-P to extractable P decreased to less than 10% in the 60-70cm depth, as Fe-P dominated at this level. The content of water-soluble P, potentially the main source of eutrophication, was higher in NRS than in RS. These results indicated that the RS used in plastic film houses contributed to the removal of water-soluble salts but only slightly decreased the phosphate concentration.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.1
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• pp.27-37
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• 2002

With increasing the concerns of health improving foods. the demands of C. boreale M., which is a perennial flower and has been historically used for a natural medicine, become higher, recently, However, wild C. boreale M. collected in a mountatinous area is limited and not enough to cover all demands. The cultivation system and fertilization strategy are required to produce much amount of C. boreale M. with a good quality. We investigated the effects of soil amendment application on plant growth and effective components of C. boreale M. to develop efficient cultivation system. C. boreale M. was cultivated in a pot scale, and lime, fly ash, poultry manure compost and swine manure compost as an amendment applied with rate of 2, 20, 150 and $150Mg\;ha^{-1}$, respectively. Here, chemical fertilizers were applied with the same level ($N-P_2O_5-K_2O=150-80-80kg\;ha^{-1}$) in all treatments. Flower yields of C. boreale M., edible part as a natural medicine, were increased to 37 and 27% by swine and poultry manure compost application, respectively. Poultry manure compost amending (NPK+PMC) increased 3.6 times of proline content and 58% of total amino acids in the flower part more than chemical fertilization (NPK). But the contents of amino acids did not increase with amending liming materials like lime and fly ash. Cumambrin A, which is a sesquiterpene compound and has the effect of blood-pressure reduction, increased to 34 and 19% by lime and fly ash applications, respectively. Cumambrin A was significantly correlated with calcium content in the flower part of C. boreale M. Conclusively, soil amendments like compost and liming materials might contribute to increase the yields and quality of C. boreale M.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.3
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• pp.272-279
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• 1988

A pot experiment was conducted to define the effect of various soil phosphorus fractions for soybean yield and the relations of between various soil phosphorus fraction and each other in 11 upland soils with different capacities of phosphorus fixation and physico-chemical properties of soils. The effect of phosphorus fertilization was high in soils with high capacities of phosphorus fixation and low available phosphorus, and soybean yield was showed significant relationship with available phosphorus and inorganic soil phosphorus fractions. Fractional recovery of added phosphorus in soils were showed various range of 2.5-91.7%, and mean value of soils was 48.5%. In the relationships among the soybean yield, plant phosphorus content, phosphorus uptake and available phosphorus, inoganic phosphorus at flowering stage, soybean yield were showed significant relationship with available phosphorus content, phosphorus uptake were all showed significant correlation without Fe-P, but Fe-P was showed except Jeju soil. Al-P/Fe-P ratio was increased by phosphorus fertilization in soils at flowering stage, and in the relationships between Al-P/Fe-P ratio and soybean yield, phosphorus uptake, soil and plant phosphorus were showed high significant correlation, but Fe-P was not showed at flowering stage. P sorbed by soils from P 20ppm solution was decreased by phosphorus fertilization, and then decreasing rate was higher in soils with low capacity of phosphorus fixation then high phosphorus fixing soils. Also P sorbed was showed negatively high significant correlation with available phosphorus, plant phosphorus, phosphorus uptake and soil inorganic phosphours except Fe-P, and soybean yield was not showed.