Impacts of Some Soil Properties on Growth, Yield, and Splitting of Pistachio in Anar Area, Rafsanjan

‍‍‍‍‍‍Pistachio is one of the most important strategic and exportable crops in Iran; therefore, identification of the factors affecting its growth is necessary for its sustainable production. The objectives of this investigation were to identify the major soils under pistachio and to evaluate the effects of their characteristics on the growth, yield and splitting of pistachio. Anar region, located in 75 km northwest of Rafsanjan, was selected for this study in 2006. Gardens with the same management practices, pistachio cultivar, water quality, and irrigation interval that contained trees varying in growth status were sought. Finally, six gardens were chosen and each garden was divided into two parts: desirable and undesirable growth. In each part, three replicates and in each replicate three trees were selected. Soil sampling was done for 0-40 and 40-80 cm depths to analyze selected soil physical and chemical properties. Yield, fruit splitting, perimeter of trunk, length of shade cover and height of the trees were also determined for each replicate. In each part of the gardens, one soil profile was studied to determine soil classification up to the family level. Results showed that high salinity and clay content decrease pistachio yield significantly. Clay content had also showed a negative significant correlation with fruit splitting, diameter of trunk, length of shade cover and height of the trees. Therefore, preparation of soil salinity and texture maps are recommended for proper pistachio management. Results indicate that soil consistency in dry state of the parts with "undesirable" growth was harder than that of the parts with desirable growth. Also, soil classification information at the family level could not be used reasonably to distinguish the effects of different soil types on pistachio yield.