Stochastic Optimisation of Integrated Sorghum Value Chain Management for Food Security in Northern Nigeria

Sorghum is the most widely grown cereal crop in northern Nigeria and a primary food security crop for rural and peri-urban populations. The sorghum value chain from production through processing to consumption involves multiple decision-making nodes under conditions of significant uncertainty arising from climate variability, market price fluctuations, and infrastructural constraints. This study develops an original stochastic optimisation framework for integrated sorghum value chain management that simultaneously considers production, processing, and distribution decisions under uncertainty. The theoretical contribution is a two-stage stochastic programming model with recourse, formulated to minimise expected total value chain cost and food insecurity risk simultaneously, incorporating uncertainty in yields, processing capacity availability, and market prices as stochastic parameters modelled by scenario trees calibrated from historical data. The model is solved using decomposition algorithms adapted for large-scale stochastic programs. The empirical application uses value chain data collected from primary surveys of 200 sorghum farmers, 30 processors, and 20 distributors across Kano, Kaduna, Zamfara, and Sokoto States (North West zone). Computational experiments demonstrate that the stochastic solution achieves a 23 percent improvement in expected food security outcomes compared to the deterministic solution under simulated uncertainty scenarios. Sensitivity analysis identifies processing capacity expansion and cold storage investment as the highest-value interventions. The study draws on stochastic programming theory, food system resilience literature, and value chain management methodology. Original contributions include the integrated multi-tier stochastic model and the calibrated scenario tree for northern Nigerian agricultural conditions. Keywords: stochastic optimisation, sorghum value chain, food security, northern Nigeria, supply chain