تاثیر حذف مواد سیمانی در اندازه‏گیری بافت خاکهای ایران

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد، گروه علوم و مهندسی خاک، دانشکده مهندسی و فناوری، دانشگاه تهران، کرج، ایران

2 دانشیار گروه علوم و مهندسی خاک، دانشکده مهندسی و فناوری، دانشگاه تهران، کرج، ایران

3 دانشیار موسسه تحقیقات خاک و آب، ﺳﺎزﻣﺎن ﺗﺤﻘﯿﻘﺎت، آﻣﻮزش و ﺗﺮوﯾﺞ ﮐﺸﺎورزی، ﮐﺮج، اﯾﺮان

چکیده

در آزمایشگاه‏های خاکشناسی ایران برای تعیین منحنی توزیع اندازه ذرات اولیه، روش‏ها و راهکارها و پیش‏تیمارهای مختلفی برای حذف مواد سیمانی خاک استفاده می‏شود که در بسیاری از شرایط امکان مقایسه نتایج و همچنین ارزیابی دقت آنها را دشوار می­سازد. پژوهش حاضر برای رسیدن به یک راهکار مشخص که در عین سادگی و ارزان بودن، دقت قابل قبولی نیز داشته باشد، انجام گردید. ابتدا 112 نمونه خاک از 16 استان مختلف از خاک‏های سطحی و عمقی برداشت و سپس با انتخاب 91 نمونه با استفاده از روش هیدرومتر با و بدون حذف کلیه مواد سیمانی شامل مواد آلی، آهک، اکسیدهای آهن و آلومینیوم و حذف توأم ماده آلی و اکسید آهن مورد تجزیه مکانیکی قرار گرفتند. نتایج نشان داد که حذف مواد سیمانی سبب افزایش بخش رس و کاهش بخش سیلت و شن می‏گردد. حذف ماده آلی و اکسید آهن به ترتیب برای خاک‏هایی که بیش از 4 درصد ماده آلی (5/2 درصد کربن آلی) و یا  2 درصد اکسید آهن دارند و یا واجد یک یا چند ویژگی خاص و متمایز از خاکهای رایج کشاورزی هستند، ضرورت دارد. همچنین زمانی که مجموع ماده آلی و اکسید آهن از 5 درصد بیشتر می‏شود، بطور میانگین حذف اکسید آهن و مواد آلی سبب افزایش 7 درصدی در میزان خالص رس می‏شود. بیشتر خاکهای ایران میزان آهک بالایی دارند. ولی در اغلب آن­ها آهک به فرم ذرات اولیه در خاک ظاهر می­شود. بنابراین حذف آهک در خاکهای سبک و متوسط که میزان آهک آنها بیش از 10 درصد باشد توصیه نمی‏شود. نتایج این پژوهش نشان داد که عدم حذف مواد سیمانی برای خاکهایی که حذف این مواد در آنها ضروری است می‏تواند منجر به تعیین نادرست کلاس بافت خاک شود.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

The Effect of Cement Removal in Measuring the Texture of Iran Soils

نویسندگان [English]

  • Mortaza Yavari 1
  • Mohammadhosein Mohammadi 2
  • Karim Shahbazi 3
1 M.Sc. Student, Dep. of Soil Sciences and Engineering, Faculty of Engineering and Technology, University of Tehran, Karaj, Iran
2 Associate Professor Dep. of Soil Sciences and Engineering, Faculty of Engineering and Technology, University of Tehran, Karaj, Iran
3 Research Associate Professor, Soil and Water Research Institute, AREEO, Karaj, Iran
چکیده [English]

In soil laboratories of Iran to determine the initial soil particle size distribution (PSD) curve, different methods and strategies and pretreatments are used to remove soil cement materials, which in many cases make it difficult to compare the results and also evaluate their accuracy. The current research was performed to achieve an economical, simple and accurate protocol to mesure the soil PSD analysis. First, 112 soil samples from the top and sub soils were collected from 16 provinces. Then 91 soil samples were selected based on hydrometer method and they were analyzed mechanically with and without removal of different cement agents; such as Organic matter, lime, iron and aluminum oxides and combined removal of organic matter and iron oxide. Results showed that the removal of cement agent increases the clay fraction and reduces the silt and sand fractions. The removal of cement agents should be conducted where i) organic matter content is more than %4 or ii) iron oxides is more than %2 or iii) the amount of  organic matter + iron oxides is more than %5. In average, the removal of organic matter and iron oxide increases clay fraction 7%. Since the carbonates are often exist as the primary particles in the Iranian soils, the removal of carbonates is not suggested from the soils with more than %10 carbonates. Finally it is concluded that the cement agent in some soils may cause incorrect determination of soil texture class.

کلیدواژه‌ها [English]

  • Particle size distribution
  • Cement agents
  • Soil Texture

مراجع

Angers, D. A. (1998). Water-stable aggregation of Quebec silty clay soils: some factors controlling its dynamics. Soil and Tillage Research, 47(1-2), 91-96.
Arya, L. M., and Paris, J. F. (1981). A physicoempirical model to predict the soil moisture characteristic from particle-size distribution and bulk density data 1. Soil Science Society of America Journal, 45(6), 1023-1030.
Asano, M., and Wagai, R. (2014). Evidence of aggregate hierarchy at micro-to submicron scales in an allophanic Andisol. Geoderma, 216, 62-74.
Barral, M. T., Buján, E., Devesa, R., Iglesias, M. L., and Velasco-Molina, M. (2007). Comparison of the structural stability of pasture and cultivated soils. Science of the total environment, 378(1-2), 174-178.
Barthès, B. G., Kouakoua, E., Larré-Larrouy, M. C., Razafimbelo, T. M., de Luca, E. F., Azontonde, A., and Feller, C. L. (2008). Texture and sesquioxide effects on water-stable aggregates and organic matter in some tropical soils. Geoderma, 143(1-2), 14-25.
Beare, M. H., Hendrix, P. F., and Coleman, D. C. (1994). Water-stable aggregates and organic matterfractions in conventional-and no-tillage soils. Soil Science Society of America Journal, 58(3), 777-786.
Blake, G. R., and Hartge, K. H. (1986). Bulk density 1. Methods of soil analysis: part 1-physical and mineralogical methods, pp.363-375.
Castro, C., and Logan, T. J. (1991). Liming effects on the stability and erodibility of some Brazilian Oxisols. Soil Science Society of America Journal, 55(5), 1407-1413.
Cosby, B. J., Hornberger, G. M., Clapp, R. B., and Ginn, T. (1984). A statistical exploration of the relationships of soil moisture characteristics to the physical properties of soils. Water resources research, 20(6), 682-690.
De Oro, L.A., Colazo, J.C., Avecilla, F., Buschiazzo, D.E. and Asensio, C., 2019. Relative soil water content as a factor for wind erodibility in soils with different texture and aggregation. Aeolian Research, 37, pp.25-31.
Dewis, J., and Freitas, F. (1970). Physical and chemical methods of soil and water analysis. Physical and chemical methods of soil and water analysis., (10).
Duiker, S. W., Flanagan, D. C., and Lal, R. (2001). Erodibility and infiltration characteristics of five major soils of southwest Spain. Catena, 45(2), 103-121.
Fredlund, M. D., Fredlund, D. G., and Wilson, G. W. (2000). An equation to represent grain-size distribution. Canadian Geotechnical Journal, 37(4), 817-827.
Gee, G. W., and Or, D. (2002). 2.4 Particle-size analysis. Methods of soil analysis. Part, 4(598), pp. 255-293.
Gee, G. W., and Bauder, J. W. (1986). Particle-size analysis 1. Methods of soil analysis: Part 1-Physical and mineralogical methods, (methods of soil analysis1), pp.383-411.
Holmgren, G. G. (1967). A rapid citrate-dithionite extractable iron procedure 1. Soil Science Society of America Journal, 31(2), 210-211.
Jensen, J. L., Schjønning, P., Watts, C. W., Christensen, B. T., and Munkholm, L. J. (2017). Soil texture analysis revisited: Removal of organic matter matters more than ever. PloS one, 12(5), e0178039.
Jensen, J.L., Schjønning, P., Watts, C.W., Christensen, B.T., Peltre, C. and Munkholm, L.J., 2019. Relating soil C and organic matter fractions to soil structural stability. Geoderma, 337, pp.834-843.
Jensen, D. K., Tuller, M., de Jonge, L. W., Arthur, E., and Moldrup, P. (2015). A new two-stage approach to predicting the soil water characteristic from saturation to oven-dryness. Journal of Hydrology, 521, 498-507.
Jones Jr, J. B. (2001). Laboratory guide for conducting soil tests and plant analysis. CRC press.
Karup, D., Moldrup, P., Paradelo, M., Katuwal, S., Norgaard, T., Greve, M. H., and de Jonge, L. W. (2016). Water and solute transport in agricultural soils predicted by volumetric clay and silt contents. Journal of Contaminant Hydrology, 192, 194-202.
Kunze, G. W., and Dixon, J. B. (1986). Pretreatment for mineralogical analysis. Methods of Soil Analysis: Part 1-Physical and Mineralogical Methods, pp. 91-100.
Lebron, I., Suarez, D. L., and Yoshida, T. (2002). Gypsum effect on the aggregate size and geometry of three sodic soils under reclamation. Soil Science Society of America Journal, 66(1), 92-98.
Mikutta, R., Kleber, M., Kaiser, K., and Jahn, R. (2005). Organic matter removal from soils using hydrogen peroxide, sodium hypochlorite, and disodium peroxodisulfate. Soil Science Society of America Journal, 69(1), 120-135.
Orts, W. J., Sojka, R. E., and Glenn, G. M. (2000). Biopolymer additives to reduce erosion-induced soil losses during irrigation. Industrial Crops and Products, 11(1), 19-29.
Page, A. L., Miller, R. H., and Keeney, D. R. (1982). Methods of soil analysis, part 2. Chemical and microbiological properties, 2.
Peixoto, R. S., Coutinho, H. L. C., Madari, B., Machado, P. D. A., Rumjanek, N. G., Van Elsas, J. D., ... and Rosado, A. S. (2006). Soil aggregation and bacterial community structure as affected by tillage and cover cropping in the Brazilian Cerrados. Soil and Tillage Research, 90(1-2), 16-28.
 Poeplau, C., Eriksson, J., and Kätterer, T. (2015). Estimating residual water content in air-dried soil from organic carbon and clay content. Soil and Tillage Research, 145, 181-183.
Rasiah, V., and Kay, B. D. (1994). Characterizing changes in aggregate stability subsequent to introduction of forages. Soil Science Society of America Journal, 58(3), 935-942.
Schjønning, P., McBride, R. A., Keller, T., and Obour, P. B. (2017). Predicting soil particle density from clay and soil organic matter contents. Geoderma, 286, 83-87.
Shein, E. V. (2009). The particle-size distribution in soils: problems of the methods of study, interpretation of the results, and classification. Eurasian Soil Science, 42(3), 284-291.
Shukla, M. K., Lal, R., Underwood, J., and Ebinger, M. (2004). Physical and hydrological characteristics of reclaimed minesoils in southeastern Ohio. Soil Science Society of America Journal, 68(4), 1352-1359.
Tisdall, J. M., and Oades, J. (1982). Organic matter and water‐stable aggregates in soils. Journal of Soil Science, 33(2), 141-163.
Vdović, N., Obhođaš, J., and Pikelj, K. (2010). Revisiting the particle‐size distribution of soils: comparison of different methods and sample pre‐treatments. European Journal of Soil Science, 61(6), 854-864.
Walkley, A., and Black, I. A. (1934). An examination of the Degtjareff method for determining soil organic matter, and a proposed modification of the chromic acid titration method. Soil science, 37(1), 29-38.
تحقیقات آب و خاک ایران
دوره 51، شماره 8
آبان 1399
صفحه 1947-1958

فایل ها

هم رسانی

ارجاع به این مقاله

آمار