Food–energy–soil nexus in ginger cultivation: Rhizome management for resilient and low-carbon production system

Sustainability of the food–energy–soil nexus is increasingly challenged in climate-vulnerable agroecosystems such as the Eastern Himalayas, where high rainfall, acidic soils, and disease pressure constrain ginger production. A six-year field experiment (2008–2013) was conducted to evaluate the effects of seed-rhizome dimensionality (25, 50, 150, and 200 g), mother-rhizome management (no removal or removal at 90, 110, 130, and 150 days after planting), and cushioning (application of forest leaf mulch around planted rhizomes) on crop performance, resource-use efficiency (RUE), soil health, and environmental sustainability. Thirteen strategically selected treatment combinations were evaluated in a randomized block design with three replications to represent farmer-relevant propagation and establishment practices. Optimized rhizome management significantly improved system productivity and resilience. Seed rhizomes of 150 g produced 3.3–4.7 times higher fresh rhizome yield than 25 g rhizomes, reflecting enhanced early vigor and resource mobilization. Early mother-rhizome detachment at 90 days after planting improved growth and yield under cushioned conditions, whereas delayed detachment (130–150 days) and convention practice of removing a 200 g mother-rhizome during peak rainfall increased disease incidence and reduced productivity. Notably, non-removal treatments with smaller seed rhizomes (25–50 g), particularly when cushioned, reduced bacterial wilt and soft rot incidence by 35–70%, indicating a strong role of wound avoidance and microclimate buffering in disease suppression. Economic and energy analysis revealed that 50 g seed rhizomes retained intact and cushioned achieved the highest benefit–cost ratio (3.98), representing a 112.8% increase over conventional practice, along with superior energy-use efficiency (57.8%), energy profitability (57%), and energy productivity (95.4%). These treatments also exhibited lowest global warming potential and improved eco-efficiency. Soil health indicators responded positively to optimized establishment practices, with reductions in bulk density (7.9%) and significant increases in soil aggregation (26.8%), mean weight diameter (30.9%), soil organic carbon (18%), nutrient availability (28.3% macronutrients and 46.2% micronutrients), and microbial activity (45.8%). Overall, the study demonstrates that integrating appreciate seed-rhizome size, judicious mother-rhizome management, and cushioning can enhance productivity, RUE, and soil biological functioning while reducing environmental impacts. These findings provide a robust, climate-resilient, and low-carbon pathway for sustainable ginger production in fragile Himalayan agroecosystems.