Quantum Computing Applications in Agricultural Engineering Optimisation Problems: Theoretical Foundations and Nigerian Case Studies

This study investigates the theoretical foundations and practical potential of quantum computing algorithms for solving complex agricultural engineering optimisation problems, using Nigerian agricultural engineering case studies to demonstrate quantum advantage over classical approaches. Agricultural engineering involves numerous computationally intractable optimisation problems, including large-scale irrigation network scheduling, multi-period crop-water allocation under uncertainty, and large-scale post-harvest supply chain optimisation, whose solution spaces grow exponentially with problem size beyond the reach of classical computers. Quantum computing offers theoretical potential for significant speedup on certain problem classes through quantum superposition, entanglement, and interference. This study examines the theoretical suitability of quantum annealing, variational quantum eigensolver, and quantum approximate optimisation algorithm approaches for representative agricultural engineering problem formulations. Problem formulations from three Nigerian agricultural engineering contexts are developed: multi-source irrigation scheme scheduling for the Kainji dam command area, post-harvest grain distribution network optimisation for the national grain reserve system, and renewable energy system sizing optimisation for rural agro-processing clusters. Classical intractability is demonstrated for full-scale problem instances. Quantum algorithm formulations are derived and implemented using IBM Qiskit quantum simulation and available quantum hardware. Comparative solution quality and computational efficiency are assessed. Findings demonstrate quantum advantage for specific problem structures including QUBO-formulated irrigation scheduling, with quantum annealing achieving near-optimal solutions for problem sizes intractable for classical solvers. The study contributes original quantum algorithm formulations for agricultural engineering optimisation and recommends a quantum computing readiness roadmap for Nigerian agricultural engineering research.

Keywords: quantum computing, agricultural engineering optimisation, irrigation scheduling, Nigeria, quantum algorithms.