Long-term nutrient management effects on soil pH, and electrical conductivity, in a vertisol under rice-based cropping system of Chhattisgarh plain

Abstract

Long-term nutrient management practices play a pivotal role in maintaining soil health and fertility. This study evaluated the influence of different nutrient management treatments on soil pH and electrical conductivity (EC) at two soil depths (0-15 cm and 15-30 cm) under a rice-based cropping system during Kharif seasons of 2022 and 2023. Ten nutrient management treatments were imposed, including balanced fertilization, organic amendments, and integrated nutrient management combinations. The results revealed that soil pH values ranged from 6.92 to 7.23 in the surface layer and 7.27 to 7.50 in the subsurface layer, with no statistically significant variation among treatments. Similarly, EC values varied between 0.22 and 0.27 dS m⁻¹ in the surface soil and 0.25 to 0.33 dS m⁻¹ in the sub-surface soil, showing a slight increase with higher fertilizer application but remaining within safe limits. Although statistical differences were non-significant, integrated treatments (50% NPK + FYM and 50% NPK + GM) exhibited relatively stable pH and moderate EC values, suggesting improved soil buffering and ionic balance. Overall, long-term integrated nutrient management helped maintain near-neutral soil reaction and safe salinity levels, indicating its importance in sustaining soil chemical quality under intensive cultivation.