Efficiency analysis of localized leaching method to remove salts from the soil Case Study: Pistachio orchard in Fath-Abad area of Kerman

The aim of localized leaching is to remove accumulatedsalts from the main activeroot zone in orchards and fields under localized irrigation systems and in the absence of sufficient water for leaching.The efficiency of this method has not been examined in subsurface-irrigated orchard or in conditions of localized application of amendments. Therefore, this study was carried out in winter of 1394 in a pistachio orchard in Fath-Abad area in Kerman to evaluate the potential of localized leaching method along with three treatments of irrigation water, gypsum, sulfuric acid with four repetitions to remove soluble salt from the main active pistachio root zone (wet areas around the subsurface pipe). In this leaching technique which was carried out for 5 consecutive days,two lines of low-flow drip tape at a distance of 40 cm from two sides of the tree row were used to leach salt from wet areas around the subsurface clay pipe. To compare leaching efficiency and changes in sodium and EC levels, soil sampling was carried out before and after leaching at 80 (Length)*120 (Depth) cm profile in 20 cm intervals. The results showed that application of 1000 mm of water led to effective salt leaching from the main active pistachio root zone. The application of gypsum increased the sodium and salts removal compare to irrigation water and sulfuric acid treatments. The percentage of sodium and salts leachate in gypsum treatment was about 61 and 58 percentage, respectively.Iirrigation water treatment with 56% leaching efficiency was more than the efficiency of sulfuric acid treatment (45%). Thus, due to the high efficiency of irrigation water compared to sulfuric acid, no significant differencewith gypsum treatment in salt removal and taking into account economic issues related to the amendments,applying irrigation water alone could be recommended as the appropriate strategies for practical reclamation of the studied soil.