• Title/Summary/Keyword: physico-chemical changes

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Soil Physico-chemical Properties by Land Use of Anthropogenic Soils Dredged from River Basins

  • Park, Jun-Hong;Park, Sang-Jo;Won, Jong-Gun;Lee, Suk-Hee;Seo, Dong-Hwan;Park, So-Deuk
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.4
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    • pp.341-346
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    • 2016
  • This study was conducted to analyze soil physico-chemical properties of agricultural land composed from the river-bed sediments. We investigated the changes of soil physico-chemical properties at 30 different sampling sites containing paddy, upland and plastic film house from 2012 to 2015. pH, exchangeable calcium and magnesium decreased gradually in paddy soils during the four years, whereas the available $P_2O_5$, exchangeable Ca, Mg and EC increased in upland and plastic film house soil. For the soil physical properties, bulk density and hardness of topsoil were $1.47g\;cm^{-3}$ and 21.5 mm and those of subsoil were $1.71g\;cm^{-3}$ and 25.7 mm in paddy soils. In upland soils, bulk density and hardness of topsoil were $1.48g\;cm^{-3}$ and 15.9 mm and those of subsoil were $1.55g\;cm^{-3}$ and 16.9 mm. In plastic film house soils, bulk density and hardness of topsoil were $1.42g\;cm^{-3}$ and 14.4 mm and those of subsoil were $1.40g\;cm^{-3}$ and 18.5 mm, respectively. The penetration hardness was higher than 3 MPa below soil depth 20 cm, and it is impossible to measure below soil depth 50 cm. As these results, in agricultural anthropogenic soils dredged from river basins, the pH, amount of organic matter and exchangeable cations decreased and soil physical properties also deteriorated with time. Therefore, it is needed to apply more organic matters and suitable amount of fertilizer and improve the soil physical properties by cultivating green manure crops, deep tillage, and reversal of deep soils.

The Effects of Physico-Chemical Factors on the Microbial Population in Groundwater (지하수 세균 군집에 미치는 물리화학적 환경요인의 영향)

  • 안영범;김여원;이대영;민병례;최영길
    • Journal of the Korean Society of Groundwater Environment
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    • v.5 no.4
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    • pp.215-222
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    • 1998
  • The objective of this study was to investigate the effects of physico-chemical environmental factors on the changes of bacterial population from two sites used for drinking water and eight sites polluted with various pollutant in Seoul city. In all the stations except for two sites used for drinking water, the concentrations of nitrate- nitrogen and ammonia were in excess of the criteria of groundwater quality by the result of analysis of 40 variations including physicochemical environmental factors, heavy metals, and bacterial populations. The numbers of total bacteria, heterotrophic bacteria and functional groups of bacteria were ranged from 5.1 to 41.4${\times}$10$\^$5/cells/ml and from 0.01 to 29.6${\times}$10$^4$cfu/ml, respectively. The activities of extracellular enzymes showed the ranges of 0.005∼11.3${\mu}$M/l/hr and its order to lipase, phophatase, ${\beta}$-glucosidase, cellulase, chitinase, amylase. The results of correspondence and multidimensional scaling analysis between bacterial populations and its physico-chemical environmental factors were explained the effects of physico-chemical environmental factors according to site characters and separated four group, which is accord with potential pollutants at wells.

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The Soil Improvement and Plant Growth on the Newly-reclaimed Sloped Land -VIII. Annual Changes of Soil Physico-chemical Properties and Sweet Potato Yield (신개간경사지(新開墾傾斜地) 토양개량(土壤改良)과 작물생육(作物生育)에 관한 연구(硏究) -VIII. 물리화학성(物理化學性) 년차간(年次間) 변화(變化)와 고구마 수량(收量))

  • Hur, Bong-Koo;Lee, Ki-Sang;Choi, Kwan-Soon
    • Korean Journal of Soil Science and Fertilizer
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    • v.27 no.3
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    • pp.189-194
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    • 1994
  • This experiment was conducted to obtain basic information on the improved methods of soil physico-chemical properties and sweet potato yield cultivated on a newly-reclaimed land, a Songjeong loam soil. The crop was cultivated under the six different treatments for 4years since 1985 in the field conditions. Annual changes of soil properties and sweet potato yield were investigated and analyzed. Soil bulk density increased from the second year, and also soil hardness of topsoil increased, but that of subsoil had not tendency. Average yield of sweet potato for 4years in the integrated improvement plot was 32.68ton/ha, which is increased by 59% in comparison to that of the control plot. Crop yield was in order of integrated improvement>phosphate>subsoiling>lime>compost>control plots. The soil properties of the topsoil which showed high correlation coefficient to sweet potato yield were bulk density, hardness and cation exchange capacity(CEC), and those of the subsoil were bulk density, soil moisture and CEC. Ratios of changes of soil properties except organic matter content showed high significancy to sweet potato yield. Soil physico-chemical properties of the 4th year without soil conditioners application were worse than those of 3rd year.

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Physico-chemical Changes of Commercial Ssamjang during Storage (공장식 쌈장의 저장기간에 따른 이화학적 성분변화)

  • Kim, Yong-Kook;Kim, Seong-Ju;Han, Min-Soo;Chang, Young-Il;Chang, Kyu-Seob
    • Korean Journal of Food Science and Technology
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    • v.37 no.3
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    • pp.389-396
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    • 2005
  • Physico-chemical properties of ssamjang prepared by industrial process were investigated. Overall experiments were planned by central composite design for five independent variables, kochujang mash aging period $(X_{1})$, doenjang aging period $(X_{2})$, doenjang content $(X_{3})$, sterilization temperature $(X_{4})$, and storage temperature $(X_{5})$. Storage period had no consistent effect on moisture content of ssamjang. Doenjang having longer aging period showed lower moisture content than that having shorter aging period. Titratable acidity and pH of ssamjang gradually increased and decreased with storage period, respectively, with pH of ssamjang significantly affected by aging period of doenjang and kochujang mashes, and sterilization and storage temperatures. Amino nitrogen contents of ssamjang increased during storage and were more affected by sterilization temperature than by aging period and content of doenjang, and storage temperature. Crude protein content of ssamjang irregularly changed during storage, and was slightly affected by content of doenjang.

Changes of Soil Physico-chemical Properties by Repeated Application of Chicken and Pig Manure Compost (계분 및 돈분퇴비의 연용에 의한 토양의 물리화학성 변화)

  • Chang, Ki-woon;Cho, Sung-hyun;Kwak, Jung-ha
    • Journal of the Korea Organic Resources Recycling Association
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    • v.7 no.1
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    • pp.23-30
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    • 1999
  • The changes of soil physico-chemical properties were investigated in the sandy loam soil amended with various application rates of chicken and pig manure composts. After repeated application of the composts for 3 years, total nitrogen content in soil treated with applied 120Mg/ha of chicken and pig manure composts was 2.1 g/kg equally. Organic matter content was 38.8 and 39.1 g/kg, available phosphate content was 602 and 585 mg/kg, and cation exchange capacity(CEC) was 10.1 and 12.4 cmol/kg in chicken and pig manure compost 120 Mg/ha treatment, respectively. Exchangeable K, Ca, Na, Mg contents, and electrical conductivity(EC) increased with the amount of applied compost. Also, with increased amount of applied compost, porosity of soil increased, but hardness, bulk density and Y value decreased.

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Quality and Shelf-life of Vacuum and Aerobic Packed Chevon Patties under Refrigeration

  • Rajkumar, V.;Agnihotri, M.K.;Sharma, N.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.4
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    • pp.548-553
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    • 2004
  • Patties were prepared using Barbari male goats meat (age about 4 yrs) and packed in HDPE under vacuum (VP) and aerobically (AP). Packed patties were stored at 4$\pm$1$^{\circ}C$ and evaluated for physico-chemical, microbiological and sensory changes on days 0, 5, 10, 15, 20 and 25. Overall mean water activity ($a_{w}$), moisture (%), fat (%), pH, TBA number and W-B shear force values (kg/$cm^{2}$) of patties were 0.983, 61.93, 18.39, 6.38, 0.150 and 0.86, respectively. Except pH that was significantly higher and TBA number significantly lower in VP patties, treatment had no significant (p>0.05) effect on other physico-chemical traits. However, storage period significantly (p<0.05) affected physico-chemical traits. Moisture (63.79%) and $a_{w}$ (0.985) were significantly (p<0.05) higher on day 25. Patties became firmer on day 20 onwards as indicated by higher W-B shear force. Though packaging method had no significant effect, storage period influenced microbial counts. The standard plate counts (SPC), which were initially log 5.98 CFU/g decreased significantly (p<0.05) on day 10 followed by steady increase and reaching log 4.89 on day 25. Almost similar trend was observed for psychrotrophic bacteria counts. Lactic acid bacteria counts declined as the storage period progressed. Coliforms, and yeast and mould counts were either not detected by the method used or were very low in numbers. All samples of AP patties revealed swollen, greasy and sticky surface with spongy texture on day 20 whereas only some of the VP patties shown such changes on day 20. Results indicated that vacuum packaging had definite advantage in preserving the sensory quality of patties than aerobic packaging but it did not help in extending the shelf-life beyond 15 days.

Physico-chemical changes in irradiated beef and pork loins (방사선 조사가 쇠고기 및 돼지고기의 물리화학적 특성에 미치는 영향)

  • Lee, Kyong-Ae;Lee, Yoon-Jin
    • Korean Journal of Human Ecology
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    • v.13 no.6
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    • pp.1031-1036
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    • 2004
  • Effects of irradiation on physico-chemical properties of beef and pork loins were examined. Beef and pork were irradiated at dose levels of 0, 0.5, 1, 2, 3, and 5 kGy with a use of Co-60 source. The drip loss of beef increased from 0 kGy to 5 kGy, whereas that of pork remained unchanged. TBA values of beef and pork increased due to irradiation. Irradiation caused a decrease in the lightness, redness, and yellowness of beef, whereas it did an increase in the same properties of pork. Irradiation also contributed to an increase in the solubility of salt soluble protein.

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Changes of Physico-Chemical Properties in Liquid-type Yogurt with Lactobacillus casei 00692 duirng Fermentation

  • Jeon, B.J.;Wang, M.K.;Kwak, H.S.
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2004.05a
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    • pp.345-348
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    • 2004
  • This study was carried out to find the physico-chemical attributes for liquid-type yogurt with Lactobacillus casei 911LC during 72 hr fermentation at $37^{\circ}C$. The pH decreased up to 32 hr and plauteaued thereafter. The growth of lactic acid bacteria sharply increased with $2.0{\times}\;10^6\;cfu/mL$ up to 40 hr of fermentation and slowly increased thereafter. The free amino acids produced during the fermentation reached the maximum value at 40 hr and gradually decreased thereafter. The present data showed that the range of optimum fermentation time for liquid-type yogurt using Lactobacillus casei 00692 was from 40 to 44 hr.

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Changes in Physico-chemical Properties and Mineral Contents during Buckwheat Germination (메밀 발아 중 물리화학적 특성과 무기질 함량의 변화)

  • 이명헌;손흥수
    • The Korean Journal of Food And Nutrition
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    • v.7 no.4
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    • pp.267-273
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    • 1994
  • To provide the effective application scheme and basic information of buckwheat (Fagopyrum esculentum Moench), buckwheat was germinated at 10$^{\circ}C$ for 7 days and 100 kernels weight, germination rate, root length, chemical composition and mineral contents were examined at 24 hour Intervals. During the germination period, the 100 kernels weight increased approximately 0.3g per day. The germination rate increased sharply after 2 days and the root length increased greatly after 4 days. The crude protein contents increased with germination time, whereas the carbohydrate contents decreased. The crude ash and fat contents did not differ significantly during the germination period. The Ca contents Increased for the 4th day of gemination, but gradually decreased afterwords. The Na contents increased in the initial stage of germination, but then gradually decreased. However, there were no significant change In the Mg, K. Fe. Mn and Zn contents.

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