Variability of soil electrical conductivity and sodium adsorption ratio and their impact on growth Pistachio

Soil salinity and alkalinity are considered as the most important problems in arid and semi arid areas. This study has been done to investigate the spatial variability of salinity and sodium adsorption ratio which have reciprocal effects on pistachio growth in the Kosarrize region in Rafsanjan. For this purpose a regular network of 500 meter intervals was considered and 192 soil samples were from 0-30 and collected 30-60 cm depths. Electrical conductivity of saturated soil extract (EC) and sodium adsorption ratio (SAR) were measured using standard methods. Statistical results showed that based on Pearson test, high positive correlation exists between EC and SAR at 99% confidence level. Therefore most of the salts must be of na type. Kriging maps illustrate that the variability of both parameters are greater in the first depth than the second one which is the result of different management strategies in the area. Also maps showed that Existences of excess salinity, SAR and also immethodical groundwater withdrawl and successive droughts in recent years have been considered as the main reasons of weak yield and even the loss of a major part of pistachio orchards in the region. The results showed that soil salinity and sodium in non planting areas are severe which illustrates the impact of mismanagement of the increased EC and SAR in the pistachio regions.