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

doi:10.1016/j.regsus.2026.100373

Abstract

Abstract:

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 23.99×10⁴ hm² 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.

Key words: Crop water consumption (CWC), Multi-objective optimization, Crop planting structure, Penman-Monteith (P-M) model, Hotan Oasis

HE Jinfeng, BAI Jie, CHANG Cun, JIN Jingyu, ZHAO Yongbo, LI Junli, BAO Anming, CHEN Qihao, SUN Huilan. Crop planting structural optimization over area expansion: A pathway to sustainable oasis agriculture in arid Northwest China[J]. Regional Sustainability, 2026, 7(4): 100373.

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Data type	Image acquisition time	Number of images	Data source
GF-2	February 2020	15	China Centre for Resources Satellite Data and Applications (https://data.cresda.cn/)
	July 2020	5
	September 2020	15
Sentinel-2A	March 2020	6	European Space Agency (ESA; https://dataspace.copernicus.eu/data-collections/copernicus-sentinel-missions/sentinel-2/)
	April 2020	4
	May 2020	4
	June 2020	4
	July 2020	4
	August 2020	8
	September 2020	6
	October 2020	8

Data type	Data item	Data source
Statistical yearbook	Total economic benefit, total yield, planting area of each crop, crop yield, and economic benefit per unit area	Hotan Statistical Yearbook (2000-2020) (Hotan Prefecture Bureau of Statistics, 2001-2021)
Statistical yearbook	Fertilizer application per unit area for grain crops (corn, wheat, and rice) and cash crops (cotton and vegetable)	Compilation of Cost and Benefit of Agricultural Products in China (2021) (Price Department of the National Development and Reform Commission, 2021)
Literature	Fertilizer application per unit area for fruit crops	Walnut (Zhang et al., 2023a), jujube (Liu, 2021), apricot (Li et al., 2012), and grape (Zhang et al., 2023b)
Local government report	Master plans for grain, cash, and fruit crops in Hotan City, Hotan County, Moyu County, and Lop County.	Outline of the Fourteenth Five-Year Plan for National Economic and Social Development and Vision 2035 in Hotan City (https://www.hts.gov.cn/xinxigongkai/guominjingjiheshehuifazhantongjixinxi/2/content_8204.html); Outline of the Fourteenth Five-Year Plan for National Economic and Social Development and Vision 2035 in Hotan County (http://www.htx.gov.cn/htx/ghxx/202309/f743585c95ac42a2a3a30bf0b5ca14cb.shtml); Outline of the Fourteenth Five-Year Plan for National Economic and Social Development and Vision 2035 in Moyu County (https://www.myx.gov.cn/myxrmzf/c123696/202403/59c734dd42be482e8c6242d179fcbfad.shtml); Outline of the Fourteenth Five-Year Plan for National Economic and Social Development and Vision 2035 in Lop County (https://www.xjlpx.gov.cn/file/upload/202311/01/034324201.pdf)

Category	Crop	Variable	Category	Crop	Variable
Cash crop	Cotton	x₁	Fruit-grain intercropping	Walnut-corn	x₈
Cash crop	Vegetable	x₂		Other fruit-wheat	x₉
Fruit monocropping	Walnut	x₃		Other fruit-corn	x₁₀
	Jujube	x₄	Grain monocropping	Rice	x₁₁
	Grape	x₅		Wheat	x₁₂
	Other fruits	x₆		Corn	x₁₃
Fruit-grain intercropping	Walnut-wheat	x₇

City/County	Additional constraint	City/county	Additional constraint
Hotan City	${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$ ${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$	Moyu County	${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$ ${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$ ${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$
Hotan County	${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$ ${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$	Lop County	${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$ ${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$ ${\displaystyle \sum _{i=7}^{13}{x}_{i}}\ge {A}_{grain}$

Scenario	Planting area limitation	Constraint formula
S1	The total planting area remains constant at its current level.	${\displaystyle \sum _{i=1}^{13}{x}_{i}}=A$
S2	Flexible total planting area, allowed to increase or decrease without limitation.	${\displaystyle \sum _{i=1}^{13}{x}_{i}}\in (0,+\infty)$
S3	The total planting area for grain and cash crops increased by 10.00% compared to the current level. The total planting area for fruit crops increased by 20.00% compared to the current level.	${\displaystyle \sum _{i=1}^{2}{x}_{i}}+{\displaystyle \sum _{i=7}^{13}{x}_{i}}=1.1{A}_{c}$ ${\displaystyle \sum _{i=1}^{2}{x}_{i}}+{\displaystyle \sum _{i=7}^{13}{x}_{i}}=1.1{A}_{c}$
S4	The total planting area for grain and cash crops increased by 5.00% compared to the current level. The total planting area for fruit crops increased by 15.00% compared to the current level.	${\displaystyle \sum _{i=1}^{2}{x}_{i}}+{\displaystyle \sum _{i=7}^{13}{x}_{i}}=1.05{A}_{c}$ ${\displaystyle \sum _{i=1}^{2}{x}_{i}}+{\displaystyle \sum _{i=7}^{13}{x}_{i}}=1.05{A}_{c}$
S5	The total planting area for grain and cash crops increased by 2.00% compared to the current level. The total planting area for fruit crops increased by 10.00% compared to the current level.	${\displaystyle \sum _{i=1}^{2}{x}_{i}}+{\displaystyle \sum _{i=7}^{13}{x}_{i}}=1.02{A}_{c}$ ${\displaystyle \sum _{i=1}^{2}{x}_{i}}+{\displaystyle \sum _{i=7}^{13}{x}_{i}}=1.02{A}_{c}$