Effect of Canopy Cover of Capparis decidua Forsk. on Soil Conditions in Thal Desert

Desert shrubs have a deep root system which allows them to explore the soil minerals and moisture from deeper horizons of soil and strongly support the local dwellers' livelihoods. Capparis decidua (Forsk.) Edgew, generally known as karir, a xerophytic, densely branched shrub, is widely found in arid and semi-arid areas of Pakistan. The present study was conducted at four different sites in the Thal desert to determine the canopy effect of C. decidua on soil nutrients. Soil nutrients under the plant canopy (UC), at a distance of 150 cm away from the canopy (D150) and 300 cm away from the canopy area (D300) were determined. Data revealed that the soil nutrient status was higher in UC soils than the soils of (D150) and (D300). Levels of soil NPK in UC soil vs soils of D150 and D300 was: Nitrogen (N) = 0.49% vs 0.41% & 0.34%; Phosphorus (P) = 7.2 mg/L vs. 6.1 mg/L & 5.3 mg/L; Potassium (K) = 104 mg/L vs 91 mg/L & 83 mg/L. Similarly, soil organic matter (OM) = 1.25% vs 1.05% & 0.83%; sulphur (S) = 8.75 mg/L vs. 8.09 mg/L & 7.19 mg/L. Conversely, carbonates (CO3 --), Bicarbonates (HCO3 -), and pH were lowest in UC soil, as values of CO3 -- , HCO3 - and pH in UC soil were < D150 < D300. The noted values of CO3 -- in UC soil (0.52 meq/L) < D150 soils (0.67 meq/L) < D300 soils (0.94 meq/L); HCO3 - in UC soil (42.80 meq/L) < D150 soils (45.85 meq/L) < D300 soils (53.10 meq L-1); pH- in UC soil (7.19) < D150 soils (7.26) < D300 soils (7.41) explained well this pattern. It was concluded that C. decidua improved the nutrient deprived sandy soils by enhancing the soil nutrient level.