Global transfer of salinization on irrigated land: Complex network and endogenous structure

Area of Science:

• Environmental Science
• Agricultural Economics
• Global Trade Analysis

Background:

• Globalization drives land redistribution through global supply chains.
• Interregional trade transfers embodied land and displaces environmental impacts like land degradation.
• Previous studies focused on embodied land resources, neglecting direct land degradation transfer, specifically salinization.

Purpose of the Study:

• To analyze the transfer of land degradation, focusing on salinization, within global supply chains.
• To investigate the endogenous structure of the land degradation transfer system using complex network analysis and input-output methods.
• To provide policy recommendations on food safety and irrigation practices related to salt-affected land.

Main Methods:

• Integration of complex network analysis and input-output methods.
• Quantitative analysis of saline and sodic irrigated land embodied in global final demand.
• Focus on irrigated land due to higher crop yields compared to dryland farming.

Main Results:

• Total saline and sodic irrigated land embodied in global final demand are 260,978.23 and 424,291.05 km², respectively.
• Salt-affected irrigated land is imported by developed countries and large developing countries (e.g., China, India).
• Pakistan, Afghanistan, and Turkmenistan are major exporters of embodied salt-affected land, comprising nearly 60% of global net exports.

Conclusions:

• The study quantifies the significant transfer of salinized irrigated land through international trade.
• Trade patterns reveal a concentration of embodied salt-affected land exports in specific Central Asian countries.
• The embodied transfer network exhibits a community structure, suggesting regional preferences in agricultural trade.