Evaluating Vertical Distribution of Soil Salinity Patterns Across Multiple Soil Depths in a Semi-Arid Dry Region

Soil salinization is a main problem that preventive sustainable improvement of agriculture in the arid and semi-arid regions of the Pakistan. Soil salinity accumulation across various soil depth among different tehsils in district Panjgur is poorly understood and is still lacking. This study was primarily aimed to explore the effect of soil salinity distribution among four different soil depths at three different tehsils of district Panjgur, Balochistan. This present study was consisting of three different tehsils (Panjgur, Gowargo, and Parsoom) with four soil depths (0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm). The results revealed a distinctive T-shaped distribution pattern of soil salinity in the soil profile. The dominant ions, including sodium, calcium, magnesium and potassium exhibited a clear vertical differentiation pattern, varying significantly from the top to the bottom of the soil profile. Most of the soil salinity characteristics i.e., sodium adsorption ration and exchangeable sodium percentage were found at the depth of 0-10 cm in Paroom soil. The highest pH (8.89), electrical conductivity (9.25 dS m-1), TDS (2061.5 mg L-1), calcium (72.5 meq/L), magnesium (196.3 meq/L), sodium (132.5 meq/L), potassium (8 meq/L), SAR (17.35), ESP (20.4) were found at the depth of 0-10 cm in paroom tehsil. However, highest CEC (12.8 meq/100 g) and bicarbonate (14.3 meq/L) were noted at the depth of 10-20 cm in Paroom tehsil. However, highest cation exchange capacity and bicarbonate were noted at the depth of 10-20 cm in Paroom tehsil. Minimum soil salinity characteristics were found at Gowargo tehsil as compared to other tehsils. Most of the parameters were positively correlated with sodium adsorption ratio and exchange sodium percentage. This study concluded that in terms of the vertical distribution, soil salinity in the paroom tehsil was higher than other soil types. Furthermore, our study findings propose important evidence for the understanding the soil salinity features and influencing factors of the salinization in semi-arid dry degraded soil of the panjgur region.