Seasonal Dynamics of Soil Physicochemical Properties beneath Acacia nilotica in the Arid Zone of Rajasthan

DOI: 10.22161/ijeab.114.32

Abstract:
Seasonal variability in soil physicochemical properties is a key determinant of nutrient cycling, soil fertility and carbon dynamics in arid ecosystems. This study characterized seasonal and depth-wise variation in soil pH, electrical conductivity (EC), soil organic carbon (SOC) and bulk density (BD) beneath Acacia nilotica in Sardarshahar, Churu District, Rajasthan. Soil properties were assessed at two depths (0–15 and 15–30 cm) across four seasons: winter, spring, summer and rainy. Soil pH ranged from 7.50 to 8.10, EC from 0.45 to 0.63 dS m⁻¹ and SOC from 0.32 to 0.58%, with overall means of 7.78, 0.53 dS m⁻¹ and 0.44%, respectively. The surface layer exhibited lower pH (7.68) but higher EC (0.57 dS m⁻¹) and SOC (0.5%) than the 15–30 cm layer, which recorded corresponding means of 7.87, 0.49 dS m⁻¹ and 0.38%. Seasonally, pH and EC reached their highest mean values during summer (8.0 and 0.59 dS m⁻¹, respectively), whereas SOC was highest during the rainy season (0.51%) and lowest during summer (0.37%). Surface SOC was approximately 30.7% higher than subsurface SOC, indicating a pronounced vertical gradient in organic carbon. Bulk density increased from 1.48 g cm⁻³ in the 0–15 cm layer to 1.54 g cm⁻³ at 15–30 cm depth. Overall, the observed patterns demonstrate pronounced seasonal variability in SOC and EC, relatively stable soil pH and bulk density, and greater organic carbon accumulation in the surface soil beneath A. nilotica. These findings highlight the potential importance of A. nilotica-dominated microsites for maintaining soil organic matter and associated soil functions under the strongly seasonal conditions of the Rajasthan arid zone.

Keywords:
Acacia nilotica, arid soil, bulk density, electrical conductivity, soil organic carbon, soil pH, seasonal variation, Sardarshahar

Article Info:
Received: 05 Jul 2026; Received in revised form: 03 Aug 2026; Accepted: 10 Aug 2026; Available online: 19 Aug 2026

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