Soil Localized Leaching and Reclamation with Gypsum and Sulfuric Acid: A Case Study of Pistachio Orchard, Kerman-Iran

ABSTRACT

Localized leaching method is a new reclamation leaching technique. Localized leaching method by using drip tapes allows water to be applied directly to the areas of salt accumulation. This study applied localized leaching method on a sandy loam soil in a pistachio orchard in Kerman, Iran to evaluate the impact of three treatments: adding gypsum soil remediation (G), soil remediation with sulfuric acid (SA) andirrigation water (IW) on soil remediation. Three treatments (IW, G and SA) in four repetitions were used to remove soluble salts from the Main Active Root Zone (MARZ) in a pistachio orchard which irrigated by a subsurface irrigation system. The localized leaching method consist of two T-tape pipelines at a distance of 40 cm located on both sides of the tree rows. Soil sampling was carried out before and after leaching from soil unit profiles with 80 cm (Length) × 120 cm (Depth) with 20 cm intervals. Concentrations of sodium (Na), magnesium (Mg), calcium (Ca) cations, and electrical conductivity (EC) were examined before and after leaching process. Results revealed that application of G-treatment compared to IW-treatment and SA-treatment led to more leaching of Na and Mg from the soil by 61% and 50%, respectively. The amount of leached Ca in both G-treatment and SA-treatments was less than that of IW-treatment. The leaching efficiency of total soluble salts for G, IW and SA treatments were 58%, 56% and 45%, respectively. Gypsum application could be recommended as a soil amendment. In addition, the localized leaching technique offers water-saving potential opposed to traditional leaching methods which applying water to the entire field.

KEYWORDS:

• Gypsum
• leaching efficiency
• salinity
• subsurface irrigation system
• sulfuric acid

Acknowledgments

This paper is based on a project that was supported by Falat Research Institute for Water and Sustainable Development (FRIWSD). The authors greatly appreciate Dr. Reza Hassanzadeh and Dr. Ghayoor Fatima for their help and valuable suggestions in improving the quality of the paper. In addition, we would like to express our tremendous gratitude to the staff of the FRIWSD for their assistance during the experimental work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00103624.2024.2377622