Optimizing Water–Fertilizer Coupling Across Different Growth Stages of Tomato in Yellow Sand Substrate: Toward Enhanced Yield, Quality, and Resource Use Efficiency

Summary

The tomato (Solanum lycopersicum L.) is widely cultivated in yellow sand substrate-based systems in Northwest China, contributing significantly to regional agriculture. However, suboptimal water and fertilizer management hinders the balanced optimization of yield, fruit quality, and resource efficiency. In this two-year solar greenhouse experiment (2023–2024), we employed a four-factor, three-level orthogonal design [L9(34)] to examine three irrigation regimes—full irrigation (FI 100% of crop evapotranspiration, [ETc]), mild deficit irrigation (DIM 75% ETc), and severe deficit irrigation (DIS 50% ETc)—in combination with staged fertilizer applications at the seedling, flowering/fruit-set, and peak-fruit stages. A multi-objective decision-making framework, integrating an improved entropy we