Functional Microbial Diversity and Soil Health Assessment in Organic and Conventional Rice-Jute Based Cropping Systems

Knowledge about the structural and functional microbial diversity influencing the biochemical properties and biological processes of soils in rice-jute based cropping systems in Eastern India is limited. In the present study, the Biolog EcoPlate technique was used to evaluate microbial metabolic diversity in long-term organically managed (OM) and conventional (CM) rice-jute based cropping systems for predicting soil quality in farmers' fields in Eastern India. The six cropping systems that were undertaken for this study were rice-lentil-jute (OM), rice-mustard-jute (OM), rice-potato-jute (OM), rice-lentil-jute (CM), rice-mustard-jute (CM), and rice-potato-jute (CM). The results of the present study revealed significant improvement in total soil organic carbon (SOC), microbial biomass carbon (MBC), labile C or permanganate oxidizable C (KMnO₄-C), soil enzymatic activities, carbon lability index (LI), carbon management index (CMI), and Soil Quality Index (SQI) in organic production systems compared to conventionally managed cropping systems. The average well colour development, utilisation of carbon substrates, Shannon-Weaver index (H), and Mcintosh (U) indices showed a significant variation among the cropping systems. Principal component analysis revealed a clear distinction between the organic and conventional production systems, suggesting that organically managed rice-jute based cropping systems have a more significant impact on microbial diversity compared to conventionally managed rice-jute based cropping systems. Furthermore, the results indicated a clear ranking of drivers, with management having a greater influence than crop rotation on soil abiotic and biotic properties, as even the rice-potato-jute system under organic management outperformed the rice-lentil-jute system under conventional practice. Among the cropping systems, rice-lentil-jute (OM) had the largest SOC, LI, CMI, Shannon-Weaver index, and Mcintosh indices, and SQI, followed by rice-mustard-jute (OM) and rice-potato-jute (OM). The present findings suggest that adopting the organically managed rice-lentil-jute system is pivotal for maintaining soil health and promoting agricultural sustainability in rice-jute based cropping systems and is highly recommended for the Eastern Indo-Gangetic Plains.