• Korean Journal of Environmental Agriculture
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• v.24 no.1
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• pp.1-5
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• 2005

Continuous monocropping of Chinese cabbage in Gangwon highland increased gravel and sand contents due to surface soil erosion. Nutrient leaching and Chinese cabbage growth were investigated with different treatments of gravel contents and nitrogen application levels by using $0.5m^2$ Wagner pots. Gravel contents were 0, 10, 30, 50, 70, and 90%(w/w), nitrogen application levels were 60, 120, and 240 kg/ha, and manure compost application rate was 15 ton per hectare, respectively. Wagner pots were filled with loamy sand soil mixed with 5 cm-sized gravels. Fresh weight of Chinese cabbage was decreased as gravel contents in soil increased, and particularly severely decreased at 240 kg-N/ha. Yields of Chinese cabbage were remarkably decreased at the rate of 60 kg-N/ha with 30% gravel content and 120 kg-N/ha with 50% gravel content. Most of Chinese cabbages were severely wilted by heavy N application at the rate of 240 kg-N/ha in the middle of growth stages regardless of gravel contents, while about 50% of Chinese cabbage showed wilting symptom in the treatment of more than 50% of gravel contents and 120 kg-N/ha. N content in leachate increased as gravel content and N application increased. The relationship between gravel content and N contents showed linear regression: N in leachate = 0.014(gravel content) -0.039 (r = 0.961). Particularly, $NH_4-N$ contents in leachates with more than 30% gravel content and 240 kg-N/ha ranged from $139{\sim}339mg/L$. Chinese cabbage growth in loamy sand soil containing 30%, and 50% gravel contents could be adversely affected by N application at the rate of 240, and 120 kg-N/ha, respectively.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.140-146
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• 2018

This research was conducted to determine the influence of incorporation levels of sulfur into a coir dust+pine bark medium (1:1, v/v) on the changes in the bicarbonate ($HCO_3{^-}$) concentrations and pH of soil solution, crop growth, and nutrient uptake of 'Ssanta' strawberry. In the preparing of the mixed medium, sulfur powder was added with the rate of 0 (control), 0.23, 0.45, 0.90, and $1.80g{\cdot}L^{-1}$ and Hoagland nutrient solution containing $240mg{\cdot}L^{-1}$ $HCO_3{^-}$ was supplied during the crop cultivation. The growth measurements and tissue analysis for the determination of nutrient contents were carried out 140 days after solution application and the soil solution analysis was performed every two weeks. As the level of sulfur was elevated, the overall growth of mother plants became better showing that the growth indexes except chlorophyll contents were the lowest in control treatment but the statistical differences were not found among the three treatments of $0.45g{\cdot}L^{-1}$ or higher sulfur. The higher the levels of sulfur incorporation, the higher the occurrence of runners and the growth of daughter plants. The length of the runners and the number of daughter plants occurred per mother plants were higher in the treatments of 0.90 and $1.80g{\cdot}L^{-1}$ than the three treatments of 0, 0.23, and $0.45g{\cdot}L^{-1}$, but the statistical differences were not observed between the 0.90 and $1.80g{\cdot}L^{-1}$ treatments. The rose of pH and $HCO_3{^-}$ concentrations in soil solution of root media continued all the cropping period, but those decreased slightly in the treatments of $0.90g{\cdot}L^{-1}$ or higher. The soil solution concentrations of $K^+$ and $PO_4{^3-}$ in the treatments of 0.90 and $1.80g{\cdot}L^{-1}$ was lower than those in other treatments and the statistical differences in the $Ca^{2+}$ and $Mg^{2+}$ concentrations were not observed among all treatments. The nutrient contents in tissue analyzed in this experiment were the lowest in the control treatments and those increased as incorporation rates of sulfur were elevated. Above results indicated that when 'Ssanta' strawberry is grown hydroponically and the root medium is coir dust and the pine bark (5:5, v/v) mix, the sulfur incorporation rate as pre-planting fertilizer has to be higher than $0.9g{\cdot}L^{-1}$ root medium to reduce the $HCO_3{^-}$ injury.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.173-179
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• 2018

Investigation of the optimum levels of pre-plant nitrogen for raising of hot pepper (cv. Nokkwang) plug seedlings was the objective of this research. To achieve this, the pre-plant nitrogen levels were varied to 0, 100, 250, 500, 750, 1,000, and $1,500mg{\cdot}L^{-1}$ and the other essential nutrients were controlled to equal concentrations in all treatments. All the fertilizers were added during the formulation of the mixed medium of coir dust, peatmoss, and perlite with the ratio of 35, 35, and 30% (v/v/v). The root medium containing pre-plant fertilizer was packed into 50-cell plug trays and seeds were sown. The measurement of pH and EC in every week, soil solution analysis for nutrients in week 0, 3, and 7 and growth measurements as well as tissue analysis for nutrient contents in week 7 were conducted. The pHs measured before seed sowing did not show significant differences, but the differences among treatments became significant as seedlings grow bigger. The soil solution ECs were significantly different among treatments in week 0 and these differences were diminished by degrees after week 3, resulting in no significant differences among treatments in week 7. The trends in changes of $NH_4-N$, $NO_3-N$, and other the macro-element concentrations in soil solution of root media were similar to those of ECs. The treatments of 500 and $750mg{\cdot}L^{-1}$ N were more effective than other treatments on seedling growth. The seedling growths in the treatments containing higher N than $1,000mg{\cdot}L^{-1}$ and control were severely suppressed. The elevated pre-plant N concentrations in the root medium resulted in the increase of tissue N contents. The treatments of 500 and $750mg{\cdot}L^{-1}$ N shown the highest seedling growths had 5.13% and 5.31%, respectively, in tissue N contents based on the dry weight of above ground tissue at week 7. The results of this study indicated that the optimum level of pre-plant N is 500 to $750mg{\cdot}L^{-1}$ for the raising of hot pepper plug seedlings.

• The Korean Journal of Ecology
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• v.4 no.3_4
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• pp.93-108
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• 1981

This investigation includes the sick soil phenomenon caused by the self-poisoning of Setaria italica, Sorghum nervosum, Zea mays and Miscanthus sinensis among Poaceae. It elucidates whether the poison is directly excreted from the root or the secondary product resulting from the decomposition in the soil; the effect of Miscantus sinensis on the germination and growth of other plants, and the effect of Zea mays grown between furrows to shade Angelica gigas on its growth. The results obtained are as follows; Supplied with the leakage water from the pots, in which the same plants as the test ones were grown, in anticipation of the poison to be directly excreted from their roots, Sataria itlaica and Zea mays exhibited the growth inhibition more than 30%, whereas Sorghum nervosum and Miscanthus sisnensis were not effected in growth at all. When cultivated in the soils mixed with the roots of the some plants as the test ones, in anticipation of the poison to be the secondary product resulting from the decomposition in soil, Setaria italica and Zea mays showd growth inhibition of more than 50%, which is greater than that of the case of the leakage water, and Miscanthus sinensis exhibited no inhibition either, whereas Sorghum nervosum in the 50% plot showed heavy growth inhibition of more than 80% to the case of the leakage water. The common or uncommon plants found easily in the group of Misscanthus scinenis were not affected by the extracts of the steam and leaves of Miscanthus sinensis in germination and growth. Supplied with the leakage water from the pots in which Miscanthus sinensis was grown, among Lespedeza crytobotrya, Oenothera odorata, Raphanus sativus val'. acarlthiformis, Zoysia japonica, Patrinia scabiosaefolia. which are easily found in the group of Miscanthus sinensis, only Patrinia scabiosaefolia was slightly inhibited in growth in the 100% plot, whereas the others did not show any inhibition at all. Mean while, Amaranthus patulus. Solanum nigrum, Capsella bursa-pastoris val'. triangularis, Alopecurus amurensis, Chenopodium album val'. centrorubrum, which could not be found in the group of Miscanthus sinensis, were all distinctly inhibited. In the experiment on the effect of Zea mays on the growth of Angelica gigas, its growth was severely inhibited by one-half to two thirds with the increased concentration in both the cases of growing in the mixture of the soil and the powdered root of Zea mays and being supplied with the leakage water from the pot in which Zea mays was grown.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.189-194
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• 2001

It is possible to use hairy vetch as green manure for corn not only in corn single cropping but also in double cropping system of corn and fall oats. Fall oats and hairy vetch were mixed-sown after corn harvest and harvested as forage in the early of November, and then hairy vetch stubble was over-wintered and incorporated into soil at corn planting as green manure without N fertilizer (FO+HV-GM). Other treatments were fall oats without N fertilizer on corn (FO-0N) and with N fertilizer 200kg/ha on corn (FO-200N), hairy vetch green manure without N fertilizer on corn (HV-GM), and fell winter follow without N fertilizer on corn (WF-0N). Soil nitrate content, corn growth and nitrogen uptakes, and yield of corn were measured and compared during 2-year experimental seasons. Dry matter and N amount of hairy vetch at the plot of FO+HV-GM were 60% less than those at the plot of HV-GM. The N effect of hairy vetch green manure on corn at the plot of HV-GM was similar to that at FO-200N plot for two years. Soil nitrate at the plot of FO+HV-GM was below the half of those at plots of HV-GM and FO-200N at 6-leaf stage of corn. N uptake of corn at the plot of FO+HV-GM at silking stage was 30% less than those at plot of HV-GM and FO-200N. However, soil nitrate at 6-leaf stage of corn and the amount of nitrogen uptake of corn at silking stage increased two times and 30-40 kg/ha, respectively, compared with those at the plot of FO-0N. Corn yield at FO+HV-GM decreased about 2 ton/ha due to the decrease of corn grain weight in the first year compared with plot of HV-GM and FO-200N, but its difference was not shown in succeeding second year. Corn N uptake at FO+HV-GM decreased 60 kg/ha and 20 kg/ha in 1999 and 2000, compared with plot of HV-GM and FO-200N, respectively, but increased 30kg/ha and 45kg/ha compared with the plot of FO-0N in 1999, 2000, respectively. Therefore, it is estimated that hairy vetch green manure in fall oats-corn double cropping system can reduce nitrogen chemical fertilizer on corn as much as 50-100 kg/ha although its N effect is much lower than the N effect of hairy vetch green manure in corn single cropping of which N effect is over 200 kg/ha.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.225-236
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• 1998

KSC-13906 [Erythro N-{(4,6-dimethoxypyrimidin-2-yl)aminocarbonyl} -2-(2-fluoro-1-hydroxy-n-propyl) benzenesulfonamide, US Patent 5,461,025] was investigated how can control phytotoxicity fluctuation and what a good method apply to new rice herbicide. The growth inhibition was observed when the rice plants was transplanted at a shallow depth(0 - 1cm) and leaching was low(0 - 1cm/ day) from the paddy soil. KSC-13906 appeared to move readily down into the paddy soil with water by 3cm depth in the soil column(${\phi}$ 10cm) filled with loamy sand soil under 3cm/day of leaching condition. Artificial control releasing pattern, designed as treated with KSC-13906 of 9 or 18g ai/ha either at a once or daily treated dividing volume of 1/20, 1/25 and 1/30 of the total volume, increased the safety of KSC-13906 to direct seeded and transplanted rice. The safety of KSC-13906 was also enhanced when KSC-13906 was mixed with dymron. For example, the mixture of KSC-13906 and dymron effectively reduced injury of direct seeded rice plants at 18 and 500g ai/ha, respectively, treated 7 days after transplanting. However, combination of KSC-13906 and several herbicides didn't show any synergistic effetct on herbicidal activity and safening effect on rice. However, the combination of KSC-13906+dymron (9~12+250~500g ai/ha) or KSC-13906+mefenacet+dymron(9+250+250g ai/ha) controlled almost all weeds in paddy field without causing any injury to rice and thus the combination would successfully be used as an oneshot herbicide in rice culture.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.2
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• pp.75-81
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• 1973

The morphological, physical, and chemical properties of Sonjeong series derived from acidic crystalline rocks are presented. Also it deals with the genesis and classification of the Songjeong series. Morphologically these soils have brown to dark brown loam A horizons and yellowish red to red clay loam Bt horizons with moderate, medium subangular blocky structure and thin patchy clay cutans on the ped faces. C horizons are very deep, yellowish red to yellowish brown fine sandy loam or sandy loam with original rock structure. Physically distribution of particle size indicates that clay increases with depth up to argillic horizons but below the argillic horizons clay content decrease. The moisture holding capacity is fairly good in Songjeong soils. Chemically soil reaction is strongly to very strongly acid throughout the profile and content of organic matter is less than 1 per cent except A horizons. Cation exchange capacity ranges from 5 to 9 me/100g of soils and base saturation is less than 35 per cent throughout the profile. The natural fertility of Songjeong soils are usually low. It needs lime, organic matter, and heavy application of fertilizer for the crop land. These soils occur temperate and humid climate under coniferous, deciduous, and mixed forest vegetation. Songjeong soils are classified as Red-Yellow Soils. Characteristically Songjeong soils are similar to Red-Yellow Podzolic soils in the United States but lack of A2 horizons and are quite liket Red-Yellow Soils of the Japan. According to new classification system which is 7th approximation of USDA Songjeong soils can be classified as fine loamy, mesic family of Typic Hapludults and in the FAO/UNESCO project World Soil Map as Orthic Acrisols.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.121-132
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• 2010

Soybean farms in Changnyeong were selected for hazard analysis to establish the Good Agricultural Practices (GAP) model of soybean, and physical, chemical(heavy metal) and biological(sanitary indications, foodborne pathogens) hazard analysis for cultivation environment (soil, water) was carried out. First, bow which is able to be mixed in soil and water was confirmed as physical hazard. Levels (Cd:0.01~0.103, Cu:0.001~6.036, As:0.006~3.045, Hg:ND~0.041, Pb:0.003~3.952, $Cr^{+6}$:0.007~0.496, Zn:0.001~66.500, Ni:0.003~18.010) of heavy metals in soil and water were appropriate for GAP criteria. In biological hazard, APC and coliform in soil were detected at the levels of $6.0{\pm}0.3$ and $3.6{\pm}1.6$ log CFU/g, and levels of water were $3.5{\pm}0.7$ and $1.9{\pm}0.7$ log CFU/mL, while E. coli wasn't detected in all sample. However, coliform in water wasn't appropriate for criteria, and E. coli O157 was detected about 22% in some farms, so it needs ways to prevent contamination by human and animals excrements. In conclusion, it needs proper management to prevent cross-contamination of hazards although physical and chemical hazard level were appropriate for GAP criteria while biological hazard wasn't.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.853-858
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• 2011

The cultivation methods are important for determining crop yield of green manure. The effect of cultivation methods of green manure crops (GMC) on biomass and rice yield was investigated. This experiment was conducted at Sinheung series (fine loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts from Oct. 2007 to Oct. 2008 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. Seven GMC (hairy vetch, barley, Chinese milk vetch, rye, crimson clover, oats, rattail fescue) were cultivated and incorporated on paddy soil by broadcasting before rice harvesting (BBRH) and partial tillage seeding (PTS). Among the three leguminous GMC, the biomass and N production were the highest at the hairy vetch of PTS. Among the four gramineae GMC, the biomass and N production tended to be higher in the rye of BBRH and barley of PTS. The C/N ratio (56.5~74.2) of rye was high compared with hairy vetch (14.1). Among the GMC, the incorporation of hairy vetch increased $NH_4$-N contents in rice paddy soil at 14 and 42 days after transplanting. These results showed that hairy vetch had no significant to rice yield compared with conventional fertilization. Therefore, hairy vetch seems to be the most efficient green manure crop as an alternatives to chemical N fertilizer in the central regions of Korea.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.4
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• pp.493-503
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• 2019

This study is composed of nine treatments [Control : "no neutralizing layer+vegetation layer" 3 cm, Treatment 1 : "no neutralizing layer+vegetation layer" 5 cm, Treatment 2 : "no neutralizing layer+vegetation layer" 7 cm, Treatment 3 :"neutralizing layer (cement 3 %)+ vegetation layer (cement 1 %)" 3 cm, Treatment 4 : "neutralizing layer (cement 3 %)+vegetation layer (cement 1 %)" 5 cm, Treatment 5 : "neutralizing layer (cement 3 %)+vegetation layer (cement 1 %)" 7 cm, Treatment 6 : "neutralizing layer [$(Ca{\cdot}Mg)CO_3$] +vegetation layer" 3 cm, Treatment 7 : "neutralizing layer [$(Ca{\cdot}Mg)CO_3$]+vegetation layer" 5 cm, Treatment 8 : "neutralizing layer [$(Ca{\cdot}Mg)CO_3$]+vegetation layer" 7 cm] to find out the vegetation effects according to neutralizing layer types of the acid drainage slope. There were no significant differences observed in soil hardness and soil moisture content of neutralizing layer type while highly difference of moisture content was observed according to the neutralizing and vegetation layer thickness. As for soil acidity, strong acid was shown in the control, treatment 1 and treatment 2. Neutralizing effects were outstanding in treatments of 3, 4, 5 (cement treatment group), 6, 7 and 8 (limestone treatment group). Concerning plants growth characteristics, surface coverage rates, number of germinating woody plants, plant height, and plant root status, there were excellent effects observed in the experimental groups mixed with cement (treatments 3, 4 and 5) and limestone (treatments 6, 7 and 8). At the initial stage, however, plant roots were negatively affected in cement layer treatments of 3, 4 and 5. However, no difference was shown in each layer thickness on the acid drainage slope whereas 3~5 cm thickness neutralizing layer was appropriate in consideration of economic feasibility.