Effect of soil texture on growth and yield of eastern cottonwood (Populus deltoides Bartr. ex Marsh. 77/51) in Noor alluvial plain

In recent decades, poplar cultivation as wood farming has been developed up to 50 thousand hectares using the fast growing eastern cottonwood (Populus deltoides Bartr. ex Marsh. 77/51) has become a common practice in north of Iran. The current study aimed to select appropriate sites for increasing growth and yield of this poplar clone. For this purpose, three different 20 years-old plantations on three different media naming: loam, silt-loam and silt-clay-loam soils of Noor alluvial plain in north of Iran were selected. The measurements were carried out based on 400 m2 plots with four replications. Quantitative and qualitative analysis showed significant differences among poplar trees grown on different soil textures beds. The poplar trees grown on loamy soils displayed the highest annual height increment of 1.27 m and volume of averaged tree of 0.956 m3. Values for average diameter, basal area and volume ha-1 were also highest in trees grown on loamy soil with total 29.1 cm, 32.59 m2 ha-1 and 443 m3 ha-1, respectively. The mean height of the trees in the silt- loam soil (24.47 mm) was significantly greater than that of the silt- clay- loam. Values for diameter increment and basal area of trees were higher in the silt- clay- loam than in silt- loam soil. In order to get an initial understanding of the habitat condition, clone selection and improvement operation, analyzing of soil is essential prior to planting of trees. In this case we can ensure and guarantee the plantation and the investment would be less risky.