Enhancing Soil Rehabilitation in Saline and Sandy Soils of Punjab, Pakistan Using Wastewater Reuse and Native Tree Species

Freshwater scarcity and soil salinization are major challenges in arid and semi-arid regions, severely limiting agricultural productivity. The reuse of wastewater and the integration of salt-tolerant tree species present promising strategies for rehabilitating degraded lands. However, empirical evidence on the comparative performance of native tree species under different irrigation regimes remains limited. A factorial experiment was conducted under controlled and open field conditions to evaluate the effects of three irrigation types; tap water (T1), wastewater (T2) and brackish water (T3) and three native tree species (Prosopis cineraria, Ziziphus jujuba, Acacia ampliceps) on soil physicochemical properties with 1000ml plant⁻¹ water irrigated twice a week. Soil samples (0–30cm) were analyzed for pH, EC, SOC, OM, MC, bulk density, WHC, saturation percentage, total N, available P, K⁺ and Na⁺. Wastewater irrigation (T2) significantly (p< 0.05) improved SOC with the highest SOC recorded for Z. jujuba in sandy soil pots (5.52%), followed by A. ampliceps (5.44%). OM increased markedly under T2, 9.50% for Z. jujuba. Wastewater enhanced available phosphorus (16.34 ppm for A. ampliceps), while total nitrogen increased significantly (5.37 mg/kg in P. cineraria. Conversely, brackish water (T3) led to elevated EC (8.25 dS/m), pH (8.84), and Na⁺ accumulation (2.55 meq/100g), particularly under saline soil indicating salt stress. Z. jujuba exhibited superior performance in SOC, moisture retention and nutrient accumulation under all treatments. These findings support the use of treated wastewater and native tree species to rehabilitate degraded lands, offering a dual benefit of freshwater conservation and sustainable ecosystem restoration.