Long-term on-farm assessment of diversified farming systems: productivity, soil carbon sequestration, and microbial functioning in Central India

Abstract

Conservation-based and diversified Cropping are increasingly promoted for enhancing soil health, and climate resilience, yet long-term on-farm evidence across multiple system types remains limited. This study evaluated the performance of integrated climate-friendly agricultural models under subtropical conditions in the Bastar district of India, using a long-term on-farm experiment conducted from 2014 to 2024. Three selected system domains, conservation agriculture (CA), agroforestry systems (AFS), and traditional farming systems (TFS), were assessed for productivity (rice equivalent yield), biomass production, soil carbon stocks, microbial populations, enzymatic activities, nutrient balance, and carbon sequestration potential. In CA, minimum tillage (one ploughing + one harrowing) significantly enhanced soil organic carbon (0.76%), bacterial population (7.76 log10 CFU g −1 ), and enzyme activities, including dehydrogenase, urease, and phosphatase ( p  < 0.05). Mixed cropping (maize + sorghum + sabdariffa + blackgram) produced the highest total biomass (202.87 q ha −1 ) and carbon sequestration (46.63 q ha −1 ) within CA treatments. Within AFS, diversified cropping with boundary plantations (cowpea–maize) and kitchen garden models achieved superior productivity (up to 85.21 q ha −1 ) while supporting high microbial activity and carbon gains. In TFS, dry aerobic direct-seeded rice–relay chickpea recorded significantly higher rice equivalent yield (65.32 q ha −1 ) with 23% lower input energy compared with puddled transplanted rice. Perennial tree components, particularly Tamarindus indica and Mangifera indica , contributed up to 122 Mg CO 2 -eq. ha −1 to long-term carbon storage. Overall, integrated models, especially agroforestry, delivered higher yields, improved soil physical and nutrient status, and strengthened microbial activity. These findings provide an operational pathway to scale climate-smart, carbon-efficient, and biodiversity-supportive Cropping aligned with the Sustainable Development Goals.