Long-term legumes inclusion in basmati rice-based production systems improves soil physical and chemical properties in the Indo-Gangetic Plains

This field study was conducted at Sardar Vallabhbhai Patel University of Agriculture and Technology (SVPUAT), Meerut, India, to evaluate the long-term impact (7 years, 2016 -23) of legume inclusion on soil physical and chemical properties. The experiment employed a randomized block design (RBD) with four replications and tested 5 production systems: fallow, rice–wheat–dhaincha (Sesbania), rice-kabuli chickpea-mung bean, rice-chickpea–mung bean and rice-berseem–mung bean. Soil samples were collected at 3 depths (0–15 cm, 15–30 cm and 30–45 cm) and analyzed for key soil health indicators including porosity, water holding capacity (WHC), hydraulic conductivity (HC), bulk density (ρb), pH, electrical conductivity (EC), cation exchange capacity (CEC) and available nitrogen (N), phosphorus (P) and potassium (K). Among the production systems, the rice–berseem–mung bean system demonstrated the most significant improvements in soil health. At the 0–15 cm depth, porosity increased to 46.32 % , WHC to 48.65 % and HC to 1.94 cm hr-1, while ρb decreased to 1.323 mg m-3, indicating enhanced soil structure and water retention over the fallow system. Chemical properties also improved, with CEC 26.75 C mol kg-1 and EC reduced to 0.12 dS m-1, reflecting better nutrient retention and lower salinity under the legume embodied system over fallow. Nutrient availability was highest under this system, with available N at 240.75 kg ha-1, P at 23.63 kg ha-1 and K at 279.50 kg ha-1, followed by basmati rice-wheat- Sesbania system. These findings showed the potential of the rice–berseem–mung bean system to mitigate soil degradation by improving physical and chemical soil properties, enhancing nutrient availability and promoting sustainable rice farming in the Indo-Gangetic Plains (IGP).