Crop planting structural optimization over area expansion: A pathway to sustainable oasis agriculture in arid Northwest China

Arid regions face critical challenges in balancing water resources, agricultural, and ecological sustainability. This study developed an integrated framework that combines remote sensing, the Penman-Monteith (P-M) model, and a multi-objective optimization model to optimize the crop planting structure in the Hotan Oasis, Xinjiang Uygur Autonomous Region, China, using 2020 as the baseline year. The model maximizes economic benefit while minimizing crop water consumption (CWC) and fertilizer application, subject to constraints such as croplands and water resources, food security, and policy requirements. The Hotan Oasis had 23.99×10 4 hm 2 of cropland, dominated by fruit-grain intercropping (43.65%), which accounted for 55.54% of the total CWC. Under constant and flexible total planting areas, reducing water-intensive crops such as monocropped fruits (jujube and walnut) and cotton and expanding the vegetable area can simultaneously increase grain yield (increase of 1.77%–2.21%) and economic benefit (increase of 5.33%–6.80%) while reducing CWC by 2.65% and fertilizer application by 4.37%–9.61%. However, any form of cropland expansion inevitably increased CWC (6.88%–14.76%) and fertilizer application (10.48%–20.09%), despite further gains in grain yield and economic benefit. While county-level optimization results generally aligned with these trends, specific adjustment pathways showed regional variations. These findings demonstrated that the sustainable development of the Hotan Oasis agriculture depends on internal structural adjustments and targeted crop diversification rather than spatial expansion to reconcile water use, food production, and ecological goals. This study provides a framework that supports the efficient management of water and land resources, offering a conceptual and practical reference for optimizing agricultural structures in similar arid regions worldwide.