Work

Global meta-analysis and machine learning uncover region-specific salinity thresholds and risks for sustainable wheat production under saline irrigation

Year: 2026

Type: article

Study designs: Systematic Review, Meta-Analysis

Abstract: Saline irrigation represents a pivotal alternative strategy for enhancing crop production under freshwater scarcity. However, previous assessments have mainly quantified average yield responses, while how interacting environmental and management conditions shape region-specific irrigation-water salinity thresholds and associated spatial risks remain elusive across global major breadbaskets. This study combined a meta-analysis of 551 field observations with machine learning (ML) to quantify global wheat yield responses to saline irrigation, identify optimal region-specific thresholds, and evaluate spatial risks in four major wheat-producing areas: the North China Plain (NCP), Indo-Gangetic Plain (IGP), Middle East (ME), and Central California Valley (CCV). Meta-analysis revealed that saline irrigation led to significant average yield reductions ranging from 12.4% in the NCP to 31.4% in the CCV. ML further showed that irrigation water salinity, growing-season temperature, and irrigation amount emerged as the dominant drivers, collectively explaining more than 54% of yield variation. An optimum irrigation amount of 500 mm was optimal for maximizing yield under saline conditions. Region-specific best practices included border irrigation at flowering (FL) and grain-filling stages for the NCP, drip irrigation at these stages for the IGP, and drip irrigation at the FL stage for the ME and CCV. Spatial risk assessment revealed a mismatch between salinity tolerance thresholds and actual exposure. Under a conservative 5% yield-loss scenario, the IGP exhibited the highest model-derived salinity threshold of 4.14 dS m −1 but the largest risk area proportion due to elevated background salinity, whereas the ME faced the lowest risk, with a risk area of 7.7%, indicating high potential for saline water utilization. These findings highlight the limitations of universal water quality guidelines and demonstrate the necessity of localized management. By establishing a data-driven framework, this study provides actionable insights to safeguard global wheat supply, build climate resilience, and ensure agricultural sustainability in salt-affected environments.

Source: Environmental Research Letters

DOI: 10.1088/1748-9326/aeaf6c

Authors: Yimin Fang, Guoyong Leng, Linfei Yu, Jiali Qiu, Xiaoyong Liao

Institutions: Chinese Academy of Sciences, Institute of Geographic Sciences and Natural Resources Research, University of Chinese Academy of Sciences

Language: English

Topic: Irrigation Practices and Water Management

Subfield: Soil Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDGs: Zero hunger, Clean water and sanitation

Open Access status: gold

Estimated APC paid: $3,045