Optimizing soil health: comparative effects of humic acid, PGPR, and RDF on soil properties and fertility

Soil fertility and productivity can increase with the addition of organic fertilizer. The continuous cropping, long-term use of inorganic fertilizer, soil erosion, and overgrazing may lead to a decline in soil organic matter. Soil fertility can be enhanced by using organic substances such as humic acid (HA) and root-associated bacteria like plant growth-promoting rhizobacteria (PGPR). The study aimed to compare the impact of organic (HA and PGPR) and inorganic (RDF- Recommended dose of fertilizer) fertilizer on the soil’s physicochemical parameters during the winter seasons at G.B. Pant University of Agriculture and Technology in Pant Nagar in the year of 2020-21 and 2021-22. This study used a randomized block design (RBD) with ten treatments and three replicates. The contents of the treatments used are as follows: T1; Control (Only RDF), T2; HA- 2.5 kg/ha (soil application), T3; Seeds treated with HA -20 g/kg of soil), T4; seeds treated with PGPR - 20 g/kg of seed, T5; RDF (NPK mixture), T6; RDF + HA (soil application), T7; RDF +HA (seed treatment), T8; RDF +PGPR (Seed treatment), T9; HA (soil application) +PGPR (seed treatment), T10; RDF + HA (soil application) + PGPR (seed treatment). The results showed that T10 (RDF+ HA-soil application + PGPR) had the most significant impact on the soil’s particle density (PD), water retention, organic carbon content (OC), and accessible nitrogen (N), phosphorus (P), and potassium (K) content in the soil during both years of experiment. The detailed research concluded that applying humic acid, PGPR, and RDF positively improved soil properties.