. Afyuni, M.M., Cassel, D.K., and Robarge, W.P. (1992). Effects of landscape position on soil water and corn silage yield. Soil Science Society of America Journal, 57(6): 1573-1580.
. Alizadeh, A. (2006). Soil, water, plant relationship. Astane Ghodse Razavi press, Mashhad.
. Klute, A. (1986). Water retention: Laboratory method. In: A. Klute (Ed.), Methods of Soil Analysis. Part 1: Physical and mineralogical Methods. America Society of Agron- Soil Science. Society of America, Madison, 9: 635-662.
. Wosten, J.H.M., Pachepsky, Y.A., and Rawls, W.J. (2001). Pedotransfer functions: bridging the gap between available basic soil data and missing soil hydraulic characteristics. Journal of Hydrology, 251: 123-150.
.Peterson, G.W., Cunningham, R.L., and Matelski, R.L. (1968). Moisture characteristics of Pennsylvania soil. I. Moisture retention as related to texture. Soil Science Society of America Journal, 32(2): 271-275.
. Rawls, W.J., Brakensiek, D.L., and Saxton, K.E. (1982). Estimation of soil water properties. American Society of Agricultural and Biological Engineers,Transactions of the ASA, 25(5): 1316-1320.
. Wu, L., Vomocil, J.A., and Childs, S.W. (1990). Pore size, particle size and aggregate size and water retention. Soil Science Society of America Journal, 54(4): 952-956.
. Gupta, S.C., and Larson, W.E. (1979). Estimating soil water retention characteristics from particle size distribution, organic matter percent and bulk density. Water Resources Research, 15(6): 1633-1637.
. Epebinu, O., and Nwadialo, B. (1993). Predicting soil water availability from texture and organic matter content for Nigerian soils. Communications in Soil Science and Plant Analysis, 24 (7&8): 633-640.
. De Jong, R., and Shields, J.A. (1988). Available water holding capacity maps of Alberta, Saskatchewan and Manitoba. Canadian Journal of Soil Science, 68(1): 157-163.
. Kern, J.S. (1995). Geographic pattern of soil water-holding capacity in the contiguous United States. Soil Science Society of America Journal, 59(4): 1126-1133.
. Manrique, L.A., Jones, C.A., and Dyke, P.T. (1991). Predicting soil water retention characteristics from soil physical and chemical properties. Communications in Soil Science and Plant Analysis, 22 (17&18): 1847-1860.
. Emerson, W.W. (1995). Water retention, organic C and soil texture. Australian Journal of Soil Research, 33(2): 241-251.
. Emerson, W.W., Foster, R.C., Tisdall, J.M., and Weissmann, D. (1994). Carbon content and bulk density of an irrigated natrixeralf in relation to three root growth and orchard management. Australian. Journal of Soil Research, 32(5): 939-951.
. Guilemette, T., and DesRochers, A. (2008). Early growth and nutrition of hybrid poplars fertilized at planting in the boreal forest of western Quebec. Forest Ecology and Management, 255(7): 2981-2989.
. Jafari Haghighi, M. (2003). Methods of Soil Analysis. Nedaye Zoha press, Tehran.
. Sayad, A., and Hossini, S.M. (2006). Compare the supply and return nutrients in pure and mixed plantations of Poplar and Alnus subcordata. Iranian Journal of Environmental studies, 31:(38): 93-102.
.Salehi, A., Maleki, M., Shabanpour, M., and Basiri, R. (2012). Effect of soil physical properties and groundwater level on qualitative and quantitative characteristics of poplar plantations in West of Guilan province (Case study: Guisum region). Iranian Journal of Forest and Poplar Research, 20(1): 38-49.
. Sagheb Talebi, Kh. (1996). Evaluation of forestry pure and mixed Alnus, sempervirens and poplar Avramykn on river deposits Mashlk. Iranian Journal of Research and development, 30: 100-103.
. Kelly, J.M., and Ericsson, T. (2003). Assessing the nutrition of juvenile hybrid poplar using Steady state technique and a mechanistic model. Forest Ecology and Management, 180(1-3): 249-260.