• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.859-865
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• 2011

This study looked into 110 sites of orchard fields to investigate the relationships between the physical and chemical properties of soils, including heavy metal contents, and the topographic characteristics of the fields in Jeonbuk province. The topographic distribution of orchard fields in Jeonbuk province was local valley and fans, hilly and mountains, mountain foot slopes, alluvial plains, diluvium, and fluvio-marine deposits. Forty-six percent (46%) of total orchard fields were located in the hilly and mountains. Soil texture of the local valley and fans was mostly sandy clay loam, and the soil texture of other topographical sites were varied. Bulk density, porosity, and soil hardness were not different among the various topographic sites. The content of plant available water was the highest (19.5%) in the sites of diluvium. Soil pH, electrical conductivity (EC), and exchangeable $Mg^{2+}$ content were the highest in the sites of fluvio-marine deposits, whereas the contents of soil organic matter (SOM), available phosphorus, and exchangeable $Ca^{2+}$, $K^+$, and $Na^+$ were not significantly different among the topographic sites. Also, soil pH and SOM content were generally in optimal ranges for the fruit plants in the orchard fields, but other values were mostly higher than those in optimum. In addition, the contents of heavy metals were much lower than the levels of Soil Contamination Warning Standard.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.380-386
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• 2011

Tip burn has been reported as one of the most serious physiological disorder in Chinese chives (Allium tuberosum Rottl.) cultivated in plastic film house. In this study, a physiography and chemical properties of 132 plastic film house soils were investigated to elucidate factors affecting tip burn symptom. Also influence of soil properties on tip burn was statistically determined by path analysis and association analysis including a chi-square test or logistics analysis. Probability distribution of inorganic aqueous species, such as ammonia (g) was calculated using MINTEQ program. Soil order and chemical properties, especially pH, exchangeable calcium and inorganic nitrogen, showed a significant relationship with tip burn of Chinese chives. Tip burn symptoms occur mainly in an alkaline soil classified as Alfisols. Result of linear regression and path analysis exhibited that formation of ammonia (g) from soil solution depend upon soil pH and were associated with ammonium resulting from soil organic matter or nitrate. These results indicate that tip burn symptom of Chinese chives is directly affected by ammonia gas originated from alkaline soil condition.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.903-915
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• 2011

Recently, anaerobic methane production of agricultural waste biomass has received increasing attention. Until now domestic BMP (Biochemical methane potential) studies concerned with agricultural waste biomass have concentrated on the several waste biomass such as livestock manure, food waste, and sewage sludge from WWTP (Waste water treatment plant). Especially, the lack of standardization study of BMP assay method has caused the confused comprehension and interpretation in the comparison of BMP results from various researchers. Germany and USA had established the standard methods, VDI 4630 and ASTM E2170-01, for the analysis of BMP and anaerobic organic degradation, respectively. In this review, BMP was defined in the aspect of organic material represented as COD (Chemical oxygen demand) and VS (Volatile solid), and the influence of several parameters on the methane potential of the feedstock was presented. In the investigation of domestic BMP case studies, BMP results of 18 biomass species generating from agriculture and agro-industry were presented. And BMP results of crop species reported from foreign case studies were presented according to the classification system of crops such as food crop, vegetables, oil seed and specialty crop, orchards, and fodder and energy crop. This review emphasizes the urgent need for characterizing the innumerable kind of biomass by their capability on methane production.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.492-497
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• 2011

Soil management for orchard depends on the effects of soil microbial activities. The present study evaluated the soil microbial community of 25 orchard in Gyeongnam Province by fatty acid methyl ester (FAME) method. The average concentrations in the orchard soils were $332nmol\;g^{-1}$ of total FAMEs, $94nmol\;g^{-1}$ of bacteria, $46nmol\;g^{-1}$ of Gram-negative bacteria, $42nmol\;g^{-1}$ of Gram-positive bacteria, $4.8nmol\;g^{-1}$ of actinomycetes, $54nmol\;g^{-1}$ of fungi, and $9.1nmol\;g^{-1}$ of arbuscular mycorrhizal fungi. In addition, sandy loam soils had significantly low ratio of cy19:0 to 18:$1{\omega}7c$ compared with that of loam soils (p<0.05), indicating that microbial stress decreased. The average soil microbial communities in the orchard soils were 28.1% of bacteria, 15.9% of fungi, 13.6% of Gram-negative bacteria, 12.5% of Gram-positive bacteria, 2.8% of arbuscular mycorrhizal fungi, and 1.4% of actinomycetes. The soil microbial community of Gram-negative bacteria in peach cultivating soils was significantly higher than that of pear cultivating soils (p<0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.375-379
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• 2011

This study was conducted to evaluate the effect of rice cover crop cropping systems on rice root growth in a rice field as affected by conventional tillage without rice straw or green manure crop treatment (CTFS, check plot), no-tillage without cover crops (NTNT), no-tillage amended with rape (NTRA), no-tillage amended with rye (NTRY), no-tillage amended with hairyvetch (NTHV), and no-tillage amended with Chinese milk vetch (NTCM). In 0-5 cm soil depth, dry weight of root in NTRS ($128g\;m^{-2}$) was significantly higher than in the other plots (p<0.05) at harvesting stage. In addition, content of active organic matter at 0-5 cm soil depth was $1,684g\;m^{-2}$ in NTCM, $1,309g\;m^{-2}$ in NTRA, $1,295g\;m^{-2}$ in NTRS, $1,072g\;m^{-2}$ in NTRY, $917g\;m^{-2}$ in NTHV, $434g\;m^{-2}$ CTFS, and $426g\;m^{-2}$ in NTNT treatment. In no-tillage rice cover crop cropping system, our findings suggest that NTRS and NTCM should be enhanced root growth and active organic matter in paddy field.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1118-1123
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• 2011

The changes of available silicate (Avail. $SiO_2$) contents in paddy soils (sandy loam) were assessed from data of the 41 years fertilization plots in which the continuous rice cropping experiment started in 1954 at the National Academy of Agricultural Science. The treatments were no fertilization (O), inorganic fertilization (NPK), inorganic fertilizer plus rice straw compost (NPK+C), inorganic fertilizer plus silicate fertilizer as a soil amendment (NPK+S), inorganic fertilizer plus rice straw compost and silicate fertilizer (NPK+CS) and inorganic fertilizer plus rice straw compost, silicate fertilizer and lime (NPK+CSL). Available silicate contents in NPK+S, NPK+CS and NPK in surface soil reached at the highest content ($255{\sim}330mg\;kg^{-1}$) after 41 years and then levelled off. Available silicate contents in subsurface soil (25~30 cm) were higher in NPK+C and NPK+S treatments than those in other treatments. Continuous application of silicate fertilizer affected significantly on the levels of available silicate in surface and subsurface soils. Silicate uptake of top rice was more increased by 98% in NPK+CS and NPK+CSL over NPK. Grain yield also increased by 37~47% in NPK+CS and NPK+CSL as compared to NPK. The combined applications of inorganic fertilizers with silicate as a soil amendment are recommended as the best fertilization practice for fertilizer use efficiency, enhancement of soil fertility status in the continuous rice cropping system in Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1089-1094
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• 2011

To treat non-point source pollution in Juam lake, removal efficiencies of pollutants were investigated in Bongsan constructed wetlands (CWs) at different treatment time, stages and wastewater loads. The constructed wetlands consisted of forebay, $1^{st}$ and $2^{nd}$ wetlands. The concentrations of BOD, SS, T-N, and T-P in inflow were $1.87mg\;L^{-1}$, $1.62mg\;L^{-1}$, $11.47mg\;L^{-1}$, and $4.40mg\;L^{-1}$, respectively. The removal rates of BOD, SS, T-N, and T-P in Bongsan CWs were 26, 18, 16 and 9%, respectively. The removal rates of BOD and T-N were higher than those for SS and T-P. The amounts of pollutant removal in Bongsan CWs were higher in the order of forebay > $1^{st}$ wetland > $2^{nd}$ wetland for BOD, forebay > $2^{nd}$ wetland > $1^{st}$ wetland for SS, $1^{st}$ wetland > forebay > $2^{nd}$ wetland for T-N and $2^{nd}$ wetland > forebay > $1^{st}$ wetland for T-P.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1169-1175
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• 2011

The soil chemical properties, microbial community structures and biochemical properties of lettuce or cucumber-cultivated greenhouse soil samples were analyzed to assess soil health and characterize microbial distribution in 8 locations in Korea. Although most of chemical properties were within the soil management guidelines, the available phosphate, and the contents of exchangeable potassium and calcium were higher than those of recommended levels. In the culture-dependent analysis, 841 bacterial strains were isolated from the greenhouse soils and were identified at the genus level by 16S rRNA gene sequences analysis. The dominant bacterial genera were Bacillus (35.7%), Microbacterium (9.3%), Arthrobacter (5.7%) and Lysobacter (5.1%). The abundance of pseudomonads was highly variable depending on the soil samples. In the culture-independent analysis, soil microbial community was investigated by using phospholipid fatty acid (PLFA) method. Principal component analysis (PCA) showed that a specific grouping for microbial community structure in the greenhouse soils was not observed based on cultivated crops and investigated sites. The results revealed that the greenhouses soils examined are relatively sound managed in terms of soil chemical contents and microbial properties.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.962-967
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• 2010

The influences of the different mixture of urea fertilizer and pig manure compost as a nitrogen (N) source on Chinese cabbage yield, N uptake, and N agronomic efficiency (AE) were evaluated in two soils having different soil fertility levels. Increasing urea application level was very effective to improve yield and N uptake of Chinese cabbage, and the highest yield was obtained by urea fertilization alone in two soils. On the other hand, the lowest yield and N uptake was obtained from compost alone application in two soils. There was no significant difference in terms of the nitrogen AE between low and high fertility soils that were fully applied with urea. The AE values of Chinese cabbage applied by compost alone were significantly higher in the soil having a low fertility (28.8 g $g^{-1}$) than that in soil with high fertility (16.2 g $g^{-1}$), suggesting that N in compost was more responsive in improving the yield of Chinese cabbage in low fertility soils.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.2
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• pp.83-93
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• 2011

Biochemical and enzymatic characterization for extracellular protease isolated from Cordyceps militaris cultivated on rice bran medium was investigated. C militaris produced proteolytic enzymes from 10 days after inoculation, maximum enzyme production was found at 25 days. The optimum temperature and pH of proteases production was at $25^{\circ}C$ and pH 7.0, respectively. The protease activity was observed in the four peaks (Pro-I, Pro-II, Pro-III, and Pro-IV) separated through Sephadex G-100 column chromatography. The separated protease was optimally active at $25^{\circ}C$. Optimum pH of the protease was between 7 and 8. Enzyme was also stable over at $30-80^{\circ}C$. The enzyme was highly stable in a pH range of 4-9. Protease activity was found to be slightly decreased by the addition of $Mg^{2+}$, $Mn^{2+}$, $Zn^{2+}$, $Fe^{2+}$ and $Cu^{2+}$, whereas inhibited by the addition of $Ca^{2+}$ and $Co^{2+}$ Protease activity was inhibited by protease inhibitor PMSF. On the other hand, the partially purified protease was investigated on proteolytic protease activity by zymogram gel electrophoresis using three substances (casein, gelatin and fibrin). Four active bands (F-I, FII, F-III, and F-IV) of fibrin degradation were revealed on fibrin zymogram gels. Both of F-II and FIII showed caseinolytic, fibrinolytic and gelatinolytic activities in three gels. Thermostability, pH stability, and pH-thermostability of the enzyme determined the residual fibrinolytic activity also displayed on fibrin zymogram gel. The only one enzyme (F-II) displayed over a broad range of temperature at $30-90^{\circ}C$. The FII displayed fibrinolytic activity in the pH range 3-5, but was inactivated in the range of pH 6-11. The F-I and F-III showed enzyme activity in the pH range of 6-11. In the pH-thermostability, the F-II only kept fibrinolytic activity after heating at $100^{\circ}C$ for 10, 20 and 30 min at pH 3 and pH 7, respectively. On the other hand, the F-II was retained activity until heating for 10 min under pH 11 condition. By using fibrin zymogram gel electrophoresis, extracellular fibrinolytic enzyme F-II from C. militaris showed unusual thermostable under acid and neutral conditions.