• Title/Summary/Keyword: Soil condition

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Vertical Distribution of Weed Seed in the Soil as affected by Tillage and No-till (경운과 무경운에 따른 토양 내 잡초종자의 수직적 분포양상)

  • Lee, Byung-Mo;Park, Kwang-Lai;Lee, Youn;Cho, Jeong-Rae;Lee, Sang-Min;An, Nan-Hee;Choi, Hyun-Sug;Jee, Hyeong-Jin
    • Weed & Turfgrass Science
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    • v.1 no.4
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    • pp.1-5
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    • 2012
  • A simple monitoring method was designed to evaluate seed bank in a upper soil (0 to 30 cm depth), which was observed for the pattern of vertical distribution of weed in the soil under tillage or no-tillage condition. The field experiment was established at an organic corn field located in Hwacheon in Kangwon-do from 2010 to 2011. Undistributed linear soil samples were taken using non-destructive soil sampler from 0 to 30 cm depth at the tillage or no-tillage soils. Weed seed distribution in the linear soil samples was estimated by counting the number of weed germinated according to the soil depth. Under tillage condition, the weed seeds were more evenly distributed from 0 to 30 cm depth, with being 75% of weed seeds located in 0 to 15 cm depth compared to the no-tillage condition. Soil samples taken by no-tillage condition had 85% of weed seeds within 15 cm of soil depth, with being 93% of weed seeds from 0 to 20 cm depth. The number of weeds or the number of weed species were three times higher for tillage soil compared to no-tillage soil, and the major dominant weed species were observed for annual plants, such as Echinochloa crus-gall, Mollugo pentaphylla, and Digitaria ciliaris.

Control of Root-Knot Nematode(Meloidogyne incognita Chitwood) by Root Zone Warming System (지중가온시설을 이용한 고구마뿌리흑선충 방제)

  • 신용습;연일권;최성국;최부술;이우승
    • Journal of Bio-Environment Control
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    • v.7 no.2
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    • pp.139-143
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    • 1998
  • This experiment was conducted to investigate the effect of soil heating on control of root-knot nematode(Meloidogyne incognita Chitwood) by root zone warming system. Root zone was warmed by hot water flowing through pipe set at 35cm depth from the ridge The lowest soil temperatures at 20cm depth were set at 3$0^{\circ}C$, 4$0^{\circ}C$, $50^{\circ}C$ and non-warming. under soil submerging condition and non-submerging condition. Soil heating was done for 5 days(120 hours) from Aug. 1 to Aug. 5. The root-knot nematode juvenile densities of 4$0^{\circ}C$ under submerging condition. and $50^{\circ}C$ under non-submerging condition were 0 which was expected lower than the economic injury level. The contents of OM P$_2$ $O_{5}$, Ca Mg and EC in soil were decreased by root zone warming The EC was considerably lowered under submerging condition.

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Effects of different soil moisture conditions on growth, yield and stress index of adzuki bean from paddy field cultivation

  • Chun, Hyen Chung;Jung, Ki Yuol;Choi, Young Dae;Lee, Sang Hun
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.337-337
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    • 2017
  • Accurate and optimal water supply to cereal crop is critical in growing stalks and producing maximum yields. Excessive soil moisture may cause nutrient deficiencies and oxygen deficiency. Excessive soil water during crop growth stages results in decrease of yields. In Korea, the largest agricultural lands are paddy fields. Recently, upland crops are cultivated in paddy field soils to reduce overproduced rice in Korea. In order to success this policy, it is necessary to fully understand crop response to excessive soil moisture condition from paddy field soils. Adzuki bean is one of major legumes which provide protein in daily diet. Adzuki bean has been well know its weakness to excessive soil moisture condition, In order to obtain optimal yields of adzuki bean from paddy field cultivation, it is necessary to understand response of adzuki bean under different soil moisture conditions. This study investigated characteristics of growths, yields and response degree of water stress from adzuki bean. Three cultivars were selected for this study; Chungju, Hongeon, and Arari. All adzuki beans were cultivated in a paddy field which was divided into three sections with different soil moistures. The paddy field was located in Milyang, Gyeongsangnam during 2016. One section of the paddy field had the greatest average soil moisture content as 35.1% during adzuki bean cultivation (very poor). The second greatest soil moisture section had 32.6% (somewhat poor) and the smallest soil moisture section had 28.9% of soil moisture (somewhat well). During cultivation of three cultivar adzuki beans, soil moisture contents and groundwater levels were monitored. All the characteristics of growth and yield components were measured; height, thickness, 100 seed weights etc. Stress index values were calculated by Stress Day Index (SDI). All cultivars had the greatest yields from somewhat well section. Chungju had the greatest yields throughout all three sections compared to other cultivars. Chungju had 81% greater yield than Hongeon which had the smallest yield from somewhat well section. Arari set in middle from all sections. However there was no significant differences yields from very poor and somewhat poor sections. Leaf SPAD values tended to decrease and stable carbon isotope values increased as soil moisture increased. However, Chungju had no difference across different soil moistures in SPAD and stable carbon isotope values, while Hongeon had the greatest differences across sections. These trends followed by SDI values. Chungju had the smallest SDI values compared to other cultivars, which meant that Chungju was the strongest tolerance against excessive soil moisture than other cultivars. All three cultivars showed severe decrease of yields from very poor and somewhat poor sections. Arari and Hongeon showed great decrease from somewhat well section compared to yields from upland soil. These two cultivars may not be proper cultivating in paddy fields. In conclusion, adzuki bean is very sensitive to soil moisture condition and detailed soil managements are required to obtain optimal yields of adzuki bean from paddy field cultivation.

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Studies on the Denitrification in the Submerged Paddy soil -III. Pretreatment of rice straw and silica fertilizer in submerged and upland soil Condition (논토양(土壤)의 탈질작용(脫窒作用)에 관(關)한 연구(硏究) -제(第) 3 보(報) : 볏짚 및 규산질비료(珪酸質肥料)의 시용시기(施用時期)가 탈질(脫窒)에 미치는 영향(影響))

  • Lee, Sang-Kyu;Kim, Seung-Hwan;Park, Jun-Kyu;An, Sang-Bae
    • Korean Journal of Soil Science and Fertilizer
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    • v.19 no.3
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    • pp.245-249
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    • 1986
  • A pot and laboratory experiments were conducted to find out the effects of pretreatments of rice straw and silica fertilizer in submerged and upland soil condition on the evolution of nitrous oxide with different application time. The results obtained were summarized as follows; 1. Evolution of nitrous oxide was remarkably increased with pretreatment of rice straw and silica in upland condition than that of submerged condition. 2. Effects of application time of rice straw and silica fertilizer on the evolution of nitrous oxide were high in order of two weeks before transplant > early spring (February) > late autumn (November) application. 3. The consumption ratio of carbon for the evolution of one mole nitrogen was pronounced more in submerged condition than that of pretreated in upland condition. Application of rice straw with silica fertilizer was remarkably reduced the consumpotion of carbon on the denitrification path way. 4. Amount of mineral nitrogen as $NH_4^+-N$, $NO_2^--N$, and $NO_3^--N$, and nitrification rate were remarkably high in pretreatment of rice straw and silica in upland condition than that of contineusly submerged soil condition.

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Contribution Rate on Soil Pysico-Chemical Properties Related to Fruit Quality of 'Kyoho' Grapevines (포도 '거봉' 품질에 미치는 토양이화학성의 상대적 기여도)

  • Kim, Seung-Heui;Choi, In-Myung;Han, Jeom-Wha;Cho, Jung-Gun;Park, Seo-Jun;Lim, Tae-Jun;Yun, Hea-Keun
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.782-788
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    • 2010
  • Detail management standard on soil conditions in 'Kyoho' grapes were not yet made. Therefore, this study was carried out to investigate the optimum soil environmental conditions on production of high fruit quality in 'Kyoho' grapes. We established using correlation between fruit quality and soil condition. These results were used to develop soil management guideline with promoting efficiency and minuteness in grape vineyard. Soil conditions were analyzed at total 80 vineyards in major grape producing areas such as Ansung, and Cheonan (40 orchards an area). The soil environmental factors affected fruit weight were soil pH of 36.6%, cultivation layer depth of 23.3%, and cation of 17.8%. The soil condition factors affected sugar content were soil hardness of 24.4%, cation of 24.1% and organic matter content of 22.1%. Cultivation layer depth, soil texture, and phosphate content were low as relative contribution. Coloring was involved with organic matter content, CEC (cation exchange capacity), and saturated hydraulic conductivity. while soil pH, cultivation layer depth, and phosphate content showed low contribution. Finally, relative contribution on fruit quality related with sugar content, fruit weight, and coloring were soil hardness of 28.0%, organic matter content of 25.0%, soil pH of 12.9%.

Sensitivity Analyses of Influencing Factors on Stability in Soil Cut Slope (토사 절토사면 안정성 영향인자의 민감도 분석)

  • Yoo, Nam-Jae;Park, Byung-Soo;Jun, Sang-Hyun;Cho, Han-Ki
    • Journal of Industrial Technology
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    • v.26 no.B
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    • pp.73-81
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    • 2006
  • A sensitivity analysis about effects of influencing factors on the stability of Soil cut slope was performed. Slope stability analyses were carried out under dry, rainy and seismic conditions. Dominant factors controlling the slope stability were chosen such as cohesion and internal friction angle, unit weight of soil, water table and seismic horizontal coefficient used for the slope stability during earthquake. Parametric stability analysis with those factors was performed for sensitivity analysis. As results of analyzing the sensitivity of factors under dry and rainy conditions, effects of cohesion, internal friction angle and unit weight of soil on the stability of slope are more critical in the dry condition than in the rainy condition. Cohesion and internal friction angle are more dominant factors influencing the slope stability irrespective of dry or rainy conditions than unit weight of soil and the horizontal seismic coefficient. The unit weight and the horizontal seismic coefficient affects crucially the stability according to conditions of slope formation and dry or rainy seasons. For the effect of horizontal seismic coefficient on stability of slope, safety factor of slope is not affected significantly by dry or rainy conditions. However, increase of the horizontal seismic coefficient under the rainy condition floes reduce the safety factor significantly rather than the dry condition. Therefore, it is needed that the location of the water table is assigned appropriately to satisfy the required safety factor of stability in the case of checking slope stability for the rainy and seismic conditions.

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Effects of Cutting Methods and Soil Depth on Sod Formation of Mentha spp. (박하 속 식물의 뗏장형성에 미치는 삽목방법과 토심의 영향)

  • Lee Chung-Il;Nam Sang-Yong
    • Journal of Bio-Environment Control
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    • v.15 no.2
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    • pp.190-195
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    • 2006
  • The purpose of this study was to figure out the best condition in growth and sod quality of Mentha spp. according to cutting methods and soil depth. Applemint (M. suaveolens), Peppermint (M. piperita), and Spearmint (M. spicata) were used. Regardless of cultivar and soil depth condition, the growth rate in top cutting was higher than layering method. The difference between layering and layering without apical meristem was not significant. Optimal condition for growth was 5cm depth of soil. However, the shallower the depth of the soil, the better quality of sod. Among three Mentha species, M suavelens showed plant height and node number and M. piperita had shoot number were higher than other variety. The best condition of sod was top cutting and 1cm depth of soil regardless of cultivar.

슬러지 식종에 따른 디젤연료에 오염된 토양내 n-alkane 및 isoprenoid의 변화

  • 이태호;박현철;최선열;박태주
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.04a
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    • pp.131-134
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    • 2004
  • Several physical and chemical methods have been used for remediation contaminated by oils. However the cost was very high and secondary pollution rose during treating. The purpose of this study was to comprision TPH (total petroleum hydrocarbon) removal from artificially contaminated soil by diesel with and without seeding anaerobic digested sludge. After 120 days of overall at 35$^{\circ}C$, removal efficiency of TPH with seeding sludge was 2-3 times higher than blank. Also, the more amount seeding sludge, TPH removal efficiency and CH$_4$ content more obtained. It was sad that seeding of anaerobic digested sludge was a good method for enhancing TPH removal efficiency without increasing operating cost. Sulfate, nitrate-reducing, methanogenic condition were evaluated for alkane, isoprenoid as target contaminated soil.

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Use of Anionic Surfactants To Modify Soil Surface to Retard Migration of Hydrophobic Organic Compounds (음이온 계면활성제를 이용한 유기오염물질 고정화 방안에 관한 연구)

  • 박인선;조윤경;박재우
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.05a
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    • pp.129-132
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    • 2000
  • In this research, we proposed the immobilization zone where the organic contaminant would be fixed, so that ground water could be prevented from the organic contaminants. The surfactant was adsorbed on the soil particles and the organic contaminants were partitioned into the hydrophobic tails of the surfactant in the immobilization zone. Surfactants with different molecular structures-SDDBS (sodium dodecylbenzenesulfonic acid), MADS (monoalkylated disulfonated diphenyl oxide), DADS (dialkylated disulfonated diphenyl oxide) - were used in this study. Up to the present, the research on the immolization simulated the saturated condition. But many site contaminated with organic contaminants and the zones where immobilization would be applied are unsaturated. In this research, in order to investigate the behaviors of surfactants and organic contaminants in unsaturated condition, the unsaturated columns were experimented, and their results were compared with the saturated case.

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논에서의 영양물질 배출량 추정( I ) - 모형의 개발 -

  • Chung, Sang-Ok;Kim, Hyeon-Soo
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.4
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    • pp.51-61
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    • 2002
  • The objective of this study is to develop GLEANS-PADDY model to predict nutrients loading from paddy-field areas. This model is developed by modifying the GLEANS model which is used for uplands, and composed of hydrology and nutrient submodels. The optimal field size for CLEANS-PADDY model application is about up to 50 ha with mild slope, relatively homogeneous Soils and spatially rainfall, and a single crop farming. The CLEAMS model is modified to handle ponded soil surface condition and saturated soil profile in paddy field. In the hydrology submodel of the CLEAMS-PADDY model. the ponded depth routing method is used to handle the ponded water condition of paddy field. To compute potential evapotranspiration the FAO-24 Corrected Blaney-Criddle method is used for paddy field instead of Penman-Monteith method in the CLEAMS model. In the nutrients submodel of the CLEAMS-PADDY model, the soil was assumed saturated and soil profile in the root zone was divided into oxidized and reduced zones.