Unlocking the Secrets of Soil Health: Exploring the Influence of Natural and Synthetic Nutrients on Soil Organic Carbon and Active & Passive Carbon Pool in Vertisols

The experiment carried out in this field study was between 2022 and 2023 at the (AICRP) research farm in the outward-bound farm of the College of Agriculture, Indore. Indore is a small city in the western part of Madhya Pradesh, Central India, situated on the Malwa Plateau. An experiment was conducted with three replication by using different combination of N, P levels and crop residues in RBD design. Experiment field was medium to black soil with pH of 7.63 and medium in organic carbon 0.58%. The soil was low in available nitrogen (208.0 kg/ha) medium in available phosphorus (21.0 kg/ha) and high in potassium (585 kg/ha) and divided into gross plot size of 10 x 7.2 m2 and a net plot size of 9 x 6.4 m2, respectively. During crop harvest four different depths were used to gather the soil samples: 0–10, 10–20, 20–30, and 30–40 cm. All the collected samples are examined separated for soil organic carbon, active (highly labile, labile SOC), and passive (non-labile, less labile SOC) carbon pools. The finding showed that maximum soil organic carbon (%) was observed with the application of treatment T6 treatment (FYM 6 t ha-1 + N20 P13. Similar trend was found with active (very labile, labile) and passive carbon (less labile, non-labile) pools of soil.