بررسی مقاومت مکانیکی خاک تحت سطوح مختلف تیمارهای تراکم و سیمانی شدن و تأثیر توسعه ریشه ذرت و گندم بر آن در شرایط آزمایشگاهی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری، گروه علوم و مهندسی خاک، دانشکده مهندسی و فناوری کشاورزی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج، ایران

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

3 استاد گروه علوم و مهندسی خاک، دانشکده مهندسی و فناوری کشاورزی، دانشکدگان کشاورزی و منابع طبیعی، دانشگاه تهران، کرج، ایران

چکیده

افزایش مقاومت مکانیکی خاک از طرفی سبب مستحکم­تر شدن خاک و ثبات آن در برابر عوامل بیرونی می­شود و از طرفی سبب محدودیت توسعه ریشه و فرایند جذب آب توسط ریشه از خاک اطراف آن می­گردد. در این مطالعه محدودیت­ها و مزایای احتمالی ناشی از مقاومت مکانیکی خاک در وضعیت بهینه رطوبتی بررسی شد. از دو عامل تراکم و سیمانی کردن به‌منظور افزایش مقاومت به فروروی خاک مرطوب استفاده شد و برای جلوگیری از اثرات نوسان رطوبت بر مقاومت مکانیکی اولیه خاک، از سامانه تثبیت مکش استفاده شد تا رطوبت خاک در مکش ماتریک 40 سانتی­متر (معادل با تخلخل تهویه­ای 10 درصد) تثبیت گردد. 132 واحد آزمایشی (گلدان) در سطوح مختلف تیمارهای تراکم (جرم مخصوص ظاهری معادل با 52/1، 56/1، 6/1، 66/1، 69/1 و 71/1 مگاگرم بر مترمکعب) و سیمان (سیمان اضافه شده معادل با صفر، 3/0، 6/0، 9/0، 2/1 و 5/1 درصد جرمی) اقدام به کشت گیاهان ذرت و گندم شد تا اثر احتمالی توسعه ریشه بر افزایش مقاومت مکانیکی اولیه خاک در قالب یک آزمایش فاکتوریل و طرح کامل تصادفی تعیین گردد. نتایج نشان داد که مقاومت مکانیکی خاک در اثر هر دو تیمار تراکم و سیمان از مقادیر کم تا مقادیر محدودکننده افزایش یافت و دامنه­ای از خاک­های سست تا مستحکم در اثر این دو تیمار ایجاد شد. مقاومت مکانیکی خاک در تیمار شاهد و برخی سطوح اولیه دو تیمار تراکم و سیمان در حد خاک­های سست قرار داشت ولی توسعه ریشه گیاه سبب شد استحکام خاک در تیمار شاهد و تراکم به مقدار قابل‌توجهی افزایش یابد. از طرفی توسعه ریشه سبب شد محدودیت خاک از نظر دردسترس‌بودن آب برای گیاه فراتر از حد بالای دامنه بحرانی (5/2 مگاپاسکال) قرار گیرد؛ بنابراین باتوجه‌به کارکرد مورد انتظار خاک، تغییرات مقاومت مکانیکی در اثر تراکم، سیمان و توسعه ریشه می­تواند به‌عنوان فرصت یا محدودیت عمل نماید.

کلیدواژه‌ها


عنوان مقاله [English]

Investigation of Soil Mechanical Resistance under Different Levels of Compaction and Cementation Treatments and the Effect of Maize and Wheat Root Development on It in Experimental Condition

نویسندگان [English]

  • Ehsan Ghezelbash 1
  • Mohammad Hosein Mohammadi 2
  • Mahdi Shorafa 3
1 Ph.D student, of Soil Science Department, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
2 Associated professor of Soil Science Department, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
3 Professor of Soil Science Department, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
چکیده [English]

Increasing the soil mechanical resistance firstly strengthens the soil and causes its stability against external factors, and on the other hand, restricts root development and the process of root water uptake from around soil. In this study, the limitations and possible benefits of soil mechanical resistance in an optimal moisture condition were investigated. Two factors of compaction and cementation were used to increase the soil mechanical resistance at wet soil and to prevent the effects of moisture fluctuation on the initial soil mechanical resistance, a suction buffer system was used to stabilize soil moisture at the matric suction of 40 cm (aeration porosity equal to 10%). 132 experimental units at different levels of compaction (bulk densities equal to 1.52, 1.56, 1.6, 1.66, 1.69, and 1.71 Mg.m-3) and cementation (added cement equal to 0, 0.3, 0.6, 0.9, 1.2 and 1.5 percentage) treatments, maize and wheat plants were cultivated to determine the possible effect of root development on increasing the initial soil mechanical resistance. The results showed that the soil mechanical resistance increased from low to restricting values due to both compaction and cementation treatments, and a range of loose to strong soils was created due to these two treatments. Soil mechanical resistance in the control treatment and some initial levels of the two compaction and cementation treatments were in the range of loose soils, but the root development caused a significant increase in soil strength in control and compacted treatments. On the other hand, root development caused the soil limitation in terms of soil water availability to exceed the critical limit (2.5 MPa). Therefore, according to the expected function of the soil, changes in mechanical strength due to compaction, cement, and root development can be considered as an opportunity or constraint.

کلیدواژه‌ها [English]

  • Threshold of soil mechanical resistance
  • water uptake
  • particle cementation
Abdalla, A., Hettiaratchi, D., and Reece, A. (1969). The mechanics of root growth in granular media. Journal of Agricultural Engineering Research, 236-248.
Abe, K., and Ziemer, R.R. (1991). Effect of tree roots on a shear zone: modeling reinforced shear stress. Canadian Journal of Forest Research, 1012-1019.
Al-Karni, A.A., and Al-Shamrani, M.A. (2000). Study of the effect of soil anisotropy on slope stability using method of slices. Computers and Geotechnics, 83-103.
Atkinson, J.A., Hawkesford, M.J., Whalley, W.R., Zhou, H., and Mooney, S.J. (2020). Soil strength influences wheat root interactions with soil macropores. Plant, Cell & Environment, 235-245.
Baldovino, J.d.J.A., Izzo, R.L.d.S., Pereira, M.D., Rocha, E.V.d.G., Rose, J.L., and Bordignon, V.R. (2020). Equations controlling tensile and compressive strength ratio of sedimentary soil–cement mixtures under optimal compaction conditions. Journal of Materials in Civil Engineering, 04019320.
Bischetti, G.B., Chiaradia, E.A., Epis, T., and Morlotti, E. (2009). Root cohesion of forest species in the Italian Alps. Plant and Soil, 71-89.
Bordoni, M., Meisina, C., Vercesi, A., Bischetti, G., Chiaradia, E., Vergani, C., Chersich, S., Valentino, R., Bittelli, M., and Comolli, R. (2016). Quantifying the contribution of grapevine roots to soil mechanical reinforcement in an area susceptible to shallow landslides. Soil and Tillage Research, 195-206.
Burak, E., Dodd, I.C., and Quinton, J.N. (2021). Do root hairs of barley and maize roots reinforce soil under shear stress? Geoderma, 114740.
Carter, M. (1990). Relative measures of soil bulk density to characterize compaction in tillage studies on fine sandy loams. Canadian Journal of Soil Science, 425-433.
Consoli, N.C., Festugato, L., da Rocha, C.G., and Cruz, R.C. (2013). Key parameters for strength control of rammed sand–cement mixtures: Influence of types of portland cement. Construction and Building Materials, 591-597.
Da Silva, A., Kay, B., and Perfect, E. (1994). Characterization of the least limiting water range of soils. Soil Science Society of America Journal, 1775-1781.
Davidson, D.T. (1965). Penetrometer measurements. Methods of Soil Analysis: Part 1 Physical and Mineralogical Properties, Including Statistics of Measurement and Sampling, 472-484.
de Lima, R.P., Tormena, C.A., Figueiredo, G.C., da Silva, A.R., and Rolim, M.M. (2020). Least limiting water and matric potential ranges of agricultural soils with calculated physical restriction thresholds. Agricultural Water Management, 106299.
Dexter, A. (1987). Mechanics of root growth. Plant and Soil, 303-312.
Gee, G.W., and Or, D. (2002). 2.4 Particle-size analysis. Methods of soil analysis. Part, 255-293.
Giadrossich, F., Cohen, D., Schwarz, M., Seddaiu, G., Contran, N., Lubino, M., Valdés-Rodríguez, O.A., and Niedda, M. (2016). Modeling bio-engineering traits of Jatropha curcas L. Ecological Engineering, 40-48.
Grable, A.R., and Siemer, E. (1968). Effects of bulk density, aggregate size, and soil water suction on oxygen diffusion, redox potentials, and elongation of corn roots. Soil Science Society of America Journal, 180-186.
Groenevelt, P., Grant, C., and Semetsa, S. (2001). A new procedure to determine soil water availability. Soil Research, 577-598.
Haynes, R., and Swift, R. (1987). Effect of trickle fertigation with three forms of nitrogen on soil pH, levels of extractable nutrients below the emitter and plant growth. Plant and Soil, 211-221.
Iverson, R.M. (2000). Landslide triggering by rain infiltration. Water resources research, 1897-1910.
Jin, K., Shen, J., Ashton, R.W., Dodd, I.C., Parry, M.A., and Whalley, W.R. (2013). How do roots elongate in a structured soil? Journal of Experimental Botany, 4761-4777.
Mao, Z., Saint-Andre, L., Genet, M., Mine, F.-X., Jourdan, C., Rey, H., Courbaud, B., and Stokes, A. (2012). Engineering ecological protection against landslides in diverse mountain forests: choosing cohesion models. Ecological Engineering, 55-69.
Meskini-Vishkaee, F., Mohammadi, M.H., Neyshabouri, M.R., and Shekari, F. (2015). Evaluation of canola chlorophyll index and leaf nitrogen under wide range of soil moisture International Agrophysics, 83-90.
Montrasio, L., and Valentino, R. (2008). A model for triggering mechanisms of shallow landslides. Natural Hazards and Earth System Sciences, 1149-1159.
Norris, J.E., Stokes, A., Mickovski, S.B., Cammeraat, E., Van Beek, R., Nicoll, B.C., and Achim, A. (2008). Slope stability and erosion control: ecotechnological solutions. Springer Science & Business Media.1402066767.
Pansu, M., and Gautheyrou, J. (2007). Handbook of soil analysis: mineralogical, organic and inorganic methods. Springer Science & Business Media.3540312110.
Petley, D. (2012). Global patterns of loss of life from landslides. Geology, 927-930.
Schmidt, K., Roering, J., Stock, J., Dietrich, W., Montgomery, D., and Schaub, T. (2001). The variability of root cohesion as an influence on shallow landslide susceptibility in the Oregon Coast Range. Canadian Geotechnical Journal, 995-1024.
Schwarz, M., Preti, F., Giadrossich, F., Lehmann, P., and Or, D. (2010). Quantifying the role of vegetation in slope stability: A case study in Tuscany (Italy). Ecological Engineering, 285-291.
Silk, W.K., and Wagner, K.K. (1980). Growth-sustaining water potential distributions in the primary corn root: A noncompartmented continuum model. Plant Physiology, 859-863.
Souza, R., Hartzell, S., Ferraz, A.P.F., de Almeida, A.Q., de Sousa Lima, J.R., Antonino, A.C.D., and de Souza, E.S. (2021). Dynamics of soil penetration resistance in water-controlled environments. Soil and Tillage Research, 104768.
Stokes, A., Norris, J.E., Van Beek, L., Bogaard, T., Cammeraat, E., Mickovski, S.B., Jenner, A., Di Iorio, A., and Fourcaud, T. (2008). How vegetation reinforces soil on slopes. Slope stability and erosion control: ecotechnological solutions. Springer.
Tosi, M. (2007). Root tensile strength relationships and their slope stability implications of three shrub species in the Northern Apennines (Italy). Geomorphology, 268-283.
Wu, W., and Sidle, R.C. (1995). A distributed slope stability model for steep forested basins. Water resources research, 2097-2110.