• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.475-480
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• 2001

Sensing soil organic matter is crucial for precision farming and environment friendly agriculture. Near infra-red(NIR) was utilized to measure the soil organic matter. Multivariate calibration methods, including stepwise multiple linear regression(MLR), principal components recession(PCR) and partial least squares regression(PLS), were applied to soil spectral reflectance data to predict the organic matter content. The effect of soil particle size and water content was studied. The range of soil organic matter contents was from 0.5 to 11%. Near infrared (NIR) region from 700 to 2,500nm was applied. For uniform soil particle size, result had good correlation (R$\^$2/ = 0.984, standard error of prediction= 0.596). The effect of soil particle size could be eliminated with 1st order derivative of the NIR signal. However. moist soil had a little lower correlation. R$\^$2/ was 0.95 and standard error of prediction was 0.94% using the PLS method. The results showed the possibility of soil organic matter measurement using NIR reflectance on the field.

• Korean Journal of Agricultural Science
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• v.19 no.2
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• pp.187-193
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• 1992

The effects of continuous restoration of sludge into the reclamating paddy soil and leaching test of sludge components by soil column were investigated. 1. The contents of nitrogen, phosphorus, potassium, C.E.C. and organic matter(O.M.) were increased in/on the paddy soil treated with paper mill sludge than non-treated. 2. Humic layer depth recognized by color showed the non-treated(10 cm), second year(15 cm) and third year(20 cm), respectively. 3. The effects of sludge treatment showed in the contents of O.M. such as non-treatment(0.9 %) < second year(1.39 %) < third year(1.75 %) in 10 cm depth. 4. All components in soil tested with column were increased by holding capacity of sludge, and the contamination effects of soil and ground water were not found by leaching test.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.319-323
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• 2014

This study investigates the prediction of soil chemical properties (organic matter (OM), pH, Ca, Mg, K, Na, total acidity, cation exchange capacity (CEC)) on 688 Korean soil samples using the visible-near infrared reflectance (VIS-NIR) spectroscopy. Reflectance from the visible to near-infrared spectrum (350 to 2500 nm) was acquired using the ASD Field Spec Pro. A total of 688 soil samples from 168 soil profiles were collected from 2009 to 2011. The spectra were resampled to 10 nm spacing and converted to the 1st derivative of absorbance (log (1/R)), which was used for predicting soil chemical properties. Principal components analysis (PCA), partial least squares regression (PLSR) and regression rules model (Cubist) were applied to predict soil chemical properties. The regression rules model (Cubist) showed the best results among these, with lower error on the calibration data. For quantitatively determining OM, total acidity, CEC, a VIS-NIR spectroscopy could be used as a routine method if the estimation quality is more improved.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.936-942
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• 2012

This review was to elucidate the fate of Bentazon(3-isopropyl-1H-2,1,3-benzothiadiazin-4(3H)-one-2,2-dioxide) and its metabolites in soil. Bentazon is rapidly degraded to form polar metabolites which are mostly adsorbed to soil components, such as humin or fulvic acid, as non extractable forms and mineralized into $CO_2$ by light or micro-organisms in both aerobic or nonaerobic condition. The degradation of Bentazon is dependent on the rate of organic matters in soil and the use of land for the tillage. The degradation rate is decreased as the amount of organic matters in soil increases and if the land is under use for tillage. Sorption and mobility of Bentazon depends on soil pH and the content of organic matters in soil. Usually, the sorption of the metabolites of Bentazon is decreased with increase in the mobility and pH. Almost all of Bentazon is degraded within rhizosphere or forms conjugate bonds with soil organic matters before it reaches to the ground water.

• Korean Journal of Organic Agriculture
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• v.5 no.2
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• pp.93-104
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• 1997

In order to investigate the growth response of grasses to chitosan solution amended soil were studied from the standpoint of estimating the growth stimulating adequate concentrations of chitosan solution amended soil in each grass. Three species in this experiment used were orchardgrass, tall fescue and reed canarygrass. Six different concentrations of chitosan solution amended soil were 0%(control), 0.01%, 0.05%, 0.1%, 0.5% and 1.0%, respectively. The resulte obtained were as follows ; 1. Leaf area(LA), dry weight of leaf(LW), dry weight of shoot(SHW), biological yield(BY), C/f ratio and T/R ratio were significantly different between species. 2. Growth stimulating effect by chitosan solution amended soil were found in plant length(PL) and T/R ratios of grasses. 3. Adequate concentrations of chitosan solution amended soil were different between species. The highest values of yield components and dry weight of plant parts were obtained at 0.01% in orchardgrass, 0,05% in reed canarygrass and 1.0% in tall fescue, respectively. 4. The growth response of grasses to chitosan solution amended soil were different between species. Thus, an increase in leaf area(LA) and dry weight of leaf(LW) by chitosan solution amended soil was mainly contributed to increase in dry weight of shoot(SHW) and biological yield(BY) in orchardgrass. Chitosan solution amended soil also stimulated growth of shoot and increased in biological yield(BY) in tall fescue. In reed canarygrass contributed to increase in C/F ratios. 5. Adequate concentrations of chitosan solution amended soil for an economical benefit of cultivation and dry matter production of grasses were ranged from 0.01% to 0.05% levels.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.4
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• pp.409-415
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• 1988

This study was carried out to investigate the effects of barley straw application on the eluviation of components in submerged paddy soil percolated. The chemical components of soil, percolated water and humus fraction were as follows. $NH{^+}_4$-N in percolated water and soil, $NO{^-}_3$- N in soil were not detected after prime tillering stage by absorption of rice plant. Phosphate was not affected by the application but a little amount was eluviated through a whole period. Eluviation phase of $Ca^{{+}{+}}$ was similar to $Mg^{{+}{+}}$ and the changes of $K^+$, $Na^+$ and $Cl^-$ were almost same patterns, whereas the amount of these eluviated elements in plot applied was higher than non-applied. In the plot applied, eluviation of $SO{^{-2}}_4$ was low during the tillering stage but high after heading stage, whereas the whole amount of eluviation was high during the tillering stage. Eluviation of iron in the plot applied was increased rapidly. Humus type was almost same as type B in the plot applied or not after harvest, and contents of humic acid was about 60 percent.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.3
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• pp.347-357
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• 2011

The TSP aerosols were collected at Gosan site of Jeju Island between 2003 and 2007, and their aerosol components were analyzed to examine the variations of chemical compositions with the corresponding pathways of inflowing air parcels. According to the comparison of seasonal aerosol compositions, the soil-originated components showed remarkably high concentrations during spring season. On the other hand, the concentrations of anthropogenic components were somewhat high in spring and summer seasons, but low in fall season. Based on the comparison of TSP compositions in relation to the pathways of inflowing air mass, the concentrations of anthropogenic components (nss-$SO_4^{2-}$, S, $NO_3^-$), soil-originated components (nss-$Ca^{2+}$, Al, Fe, Ca), and the heavy metals (e,g., Mn, Zn, Cr, Pb, Cu, Cd, etc.) have relatively increased with the air mass moving from China continent into Jeju area. Meanwhile, the marine-originated components showed an increasing trend with the air mass coming from North Pacific Ocean. In the seasonal and sectional comparison, the nss-$SO_4^{2-}$, $NO_3^-$, nss-$Ca^{2+}$, and Al showed comparatively high concentrations when the air mass moved from China continent during all seasons. Especially, the $NO_3^-$, nss-$Ca^{2+}$, and Al concentrations were somewhat high when the air mass moved from Korean Peninsula during summer season. It was also recognized that the Na+ concentration were high, when the air mass moved from Pacific Ocean through all seasons.

• Journal of Soil and Groundwater Environment
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• v.17 no.4
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• pp.36-43
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• 2012

Various methods are used to remediate soil contaminated with heavy metals or petroleum. In recent years, harsh physical and chemical remediation methods are being used to increase remediation efficiency, however, such processes could affect soil properties and degrade the ecological functions of the soil. Effects of soil washing, thermal desorption, and land farming, which are the most frequently used remediation methods, on the physicochemical properties of remediated soil were investigated in this study. For soils smaller than 2 mm, the soil texture were changed from sandy clay loam to sandy loam because of the decrease in the clay content after soil washing, and from loamy sand to sandy loam because of the decrease in the sand content and increase in silt content during thermal desorption, however, the soil texture remained unchanged after land farming process. The water-holding capacity, organic matter content, and total nitrogen concentration of the tested soil decreased after soil washing. A change in soil color and an increase in the available phosphate concentration were observed after thermal desorption. Exchangeable cations, total nitrogen, and available phosphate concentration were found to decrease after land farming; these components were probably used by microorganisms during as well as after the land farming process because microbial processes remain active even after land farming. A study of these changes can provide information useful for the reuse of remediated soil. However, it is insufficient to assess only soil physicochemical properties from the viewpoint of the reuse of remediated soil. Potential risks and ecological functions of remediated soil should also be considered to realize sustainable soil use.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.145-149
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• 2001

This study was performed to evaluate the growth and nodulation characters of hypernodulating soy-bean mutant, SS2-2, and to know the growth and yield performance of the mutant in infertile soil. Soil fertility was adjusted by mixing the different ratios of soil components including clay, river sand, and horticultural bed, which resulted in fertile and infertile soil. Dry weight, nitrogen concentration, and leaf nitrate reductase of each plant were measured around V6 stage (47 days after planting) and around R3 stage (82 days after planting). There were significant effects of soil fertility and soybean genotype on the total dry weights including root, nodule, stem, leaf, and pod dry weight at V6 and R3 stages. Total dry weight of hypernodulating mutant, SS2-2, was clearly less than that of its wild type, Sinpaldalkong 2. However, nodule development on the roots of SS2-2 was much greater than that of Sinpaldalkong 2, regardless of soil fertility. Though SS2-2 was smaller in plant size than Sinpaldalkong 2, genotypic difference in total nitrogen content was not significant at both V6 and R3 stages because SS2-2 fixed more nitrogen biologically than its wild type in the root nodule. The SS2-2 mutant showed lower plant yield in both infertile and fertile soil. The SS2-2 contained more crude seed protein than Sinpaldalkong 2, and was characterized with reduced top and root growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.3
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• pp.31-46
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• 1978

In order to secure the proper use of herbicides that are frequently used in Korea, the behavior of herbicides in various type of soil were studied. This study includes the variation of phytotoxicity, leaching and movement, and residual activity period of herbicides depending upon the type of soil etc. Experiments were also conducted to establish a guideline for the selection of herbicides according to the type of soil and the proper use of each herbicide in various type of soil in Korea. Experimental results showed that the behavior of herbicides could be characterized based on the series or kind of herbicides and devided into two major groups. One group (nitrofen. CNP, benthiocarb and butachlor) of herbicides showed relatively little crop injury and was very dependable. The action of this group was not remarkably influenced by soil components, rainfall and the quantity of herbicide used with the type of soil that had small adsorption capacity such as most of soil in Korea. The other group(simazine, 2, 4-D. linuron, alachlor and simetryne) showed a wide variation in it's action and retained potentially injurious effect. This group was very susceptable to using condition as well as the type of soil itself. Based on the results of various experiments the disappearance of the residual activity period of major herbicides used in upland and paddy field and the related factors were explained. It is believed that the results of this study can be used as a base for the establishment of a guideline for the proper use of each herbicide and can suggest a direction of developing new herbicides.