Effect of OC, available N, P2O5, K2O on different fractions of Zn under saline soil of Navsari District

This study examined the correlation between soil organic carbon (OC), available Nitrogen (N), Phosphorus (P2O5), Potassium (K2O) and different Zinc (Zn) fractions in salt-affected soils of Navsari district, covering saline areas during the summer of 2023-24. A total of 60 soil samples were collected from 0-20 cm and 20-40 cm depths across multiple villages in the Jalalpore taluka of Navsari district, representing the coastal saline inland Zone. Soil organic carbon (OC), available N, P2O5, K2O, and different Zinc (Zn) fractions were decreased with an increased in salinity. Correlation analysis revealed a significant relationship between OC, nutrient availability and Zn fractions under varying saline conditions and depths. The Zn fractions followed the order: Org-Zn > Fe-Mn-O-Zn > CO3-Zn > Exch-Zn >WS-Zn in saline areas. At the 0-20 cm depth, OC showed the strong negative correlations with available P2O5 and K2O, while P2O5 was positively related to K2O but negatively to CO3-Zn. Available K2O was negatively associated with CO3-Zn and WS-Zn inversely correlated with CO3-Zn. At 20-40 cm depth, OC was negatively correlated with Org-Zn, P2O5 remained positively related to K2O, and available K2O was negatively associated with both Fe-Mn-O-Zn and CO3-Zn. Exch-Zn showed negative correlations with CO3-Zn and Org-Zn. Overall, the findings indicate that higher OC tends to reduce certain nutrient and Zn fractions, while carbonate and mineral-bound Zn forms exhibit interlinked accumulation patterns influenced by nutrient availability and soil depth.