Effect rock fragment Content on Some physical quality indices of a silt loam Soil

Document Type : Research Paper


University of Urmia


This study was conducted to investigate the role of rock fragment content on water retention and soil penetration resistance curves as well as determining the correlation of soil physical quality indices with therock fragment content of the soil.A silt loam soil, containing 5% w/w 2 to 5 mm in diameter rock fragments, was used for this study. Experiment was carried out based on completely randomized design atsix treatmentsand three replications. The treatments including six levels of 5, 10, 15, 20, 25, and 30% w/w 2 to 5 mm in diameter gravel. Large drainable soil bins (40 cm × 50 cm with 50 cm depth) were used in this study. The bins were put outside (under natural conditions) after sowing of wheat (Triticum aestivumL.) and received enough amounts of water using irrigation and rainfall.There were significant differences (p<0.05) between the soil water content values in important matric suctions. The highest (i.e., 0.322 cm3 cm-3) and the lowest (i.e., 0.269 cm3 cm-3) means of water content at matric suction 100 hPa were obtained for the 10 and 30 percentage of the rock fragment content, respectively.Increase in rock fragment content of the soil significantly reduced the water content that the critical penetration resistance(2 MPa) happened. There was significant relationship between the water content of 2 MPa and rock fragment content of the soil. Increasing of the rock fragment from the normal value (5%) to 30% was causedthatthe bulk density and the infiltration time increase more than 11 and 254, respectively.


Main Subjects

Asgarzadeh, H., Mosaddeghi, M. R., Mahboubi, A. A., Nosrati, A. and Dexter, A. R. (2010) Soil water availability for plants as quantified by conventional available water, least limiting water range and integral water capacity. Plant Soil, 335 (1-2), 229–244.
Asgarzadeh, H., Mosaddeghi, M. R., Mahboubi, A. A, Nosrati, A. and Dexter, A. R. (2011) Integral energy of conventional available water, least limiting water range and integral water capacity for better characterization of water availability and soil physical quality. Geoderma, 166: 34–42.
Baetens, J. M., Verbist, K., Cornelis, W. M., Gabriels, D. and Soto, G. (2009) On the influence of coarse fragments on soil water retention. Water Resources Research, 45 (7).
Beibei, Z., Ming’an, S. and Hongbo, S. (2009) Effects of rock fragments on water movement and solute transport in a Loess Plateau soil. Comptes Rendus Geoscience, 341(6), 462-472.
Beutler, A. N., Centurion, J. F. and Silva, A. P. D. (2005) Soil resistance to penetration and least limiting water range for soybean yield in a haplustox from Brazil. Brazilian Archives of Biology and Technology, 48(6), 863-871.
Brakensiek, D. L. and Rawls, W. J. (1994) Soil containing rock fragments: effects on infiltration. Catena, 23, 99–110.
Cousin, I., Nicoullaud, B. and Coutadeur, C. (2003) Influence of rock fragments on the water retention and water percolation in a calcareous soil. Catena, 53 (2),97-114.
Da Silva, A. P., Kay, B. D. and Perfect, E. (1994) Characterization of the least limiting water range of soils. Soil Science Society of America Journal, 58(6), 1775-1781.
Dexter, A.R. (2004a) Soil physical quality; Part I. Theory, effects of soil texture, density, and organic matter, and effects on root growth. Geoderma, 120, 201–214.
Dexter, A.R. (2004b) Soil physical quality; Part II. Friability, tillage, tilth and hard- Setting. Geoderma, 120, 215–225.
Dexter, A.R. (2004c) Soil physical quality; Part III: Unsaturated hydraulic conductivity and general conclusions about S-theory. Geoderma, 120, 227–239.
Dexter, A.R., Czyż, E.A. and Gaţe, O.P. (2007) A method for prediction of soil penetration resistance. Soil &Tillage Research. 93, 412–419.
Poesen, J. and Lavee, H. (1994). Rock fragments in top soils: significance and processes. Catena, 23, 1-28.
Reynolds, W.D., Drury, C.F., Yang, X.M. and Tan, C.S. (2008) Optimal soil physical quality inferred through structural regression and parameter interactions. Geoderma, 146, 466–474.
Rücknagel, J., Rücknagel, S. and Christen, O. (2012) Impact on soil compaction of driving agricultural machinery over ground frozen near the surface. Cold Regions Science and Technology, 70, 113–116.
Soane, B.D. and van Owerkerk, C. (1994)Soil Compaction in Crop Production. Amsterdam: Elsevier.
To, J. and Kay, B.D. (2005) Variation in penetrometer resistance with soil properties: the contribution of effective stress and implications for pedotransfer functions. Geoderma, 126, 261–276.
van Genuchten, M.Th. (1980) A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Science Society of America Journal, 44, 892–898.
Verbist, K., Baetens, J., Cornelis, W. M., Gabriels, D., Torres, C. and Soto, G. (2009) Hydraulic conductivity as influenced by stoniness in degraded drylands of Chile. Soil Science Society of America Journal, 73(2), 471-484.
Zhongjie, S., Yanhui, W., Pengtao, Y., Lihong, X., Wei, X. and Hao, G. (2008) Effect of rock fragments on the percolation and evaporation of forest soil in Liupan Mountains, China. Acta Ecologica Sinica, 28(12), 6090-6098.