Improved alternate wetting and drying irrigation increases global water productivity

Area of Science:

• Agricultural Science
• Agronomy
• Water Management

Background:

• Rice is a global staple with a significant water footprint.
• Alternate wetting and drying (AWD) irrigation can improve water productivity but faces adoption challenges due to yield concerns.

Purpose of the Study:

• To quantify the effects of AWD on rice yield and water productivity.
• To identify key factors influencing AWD effectiveness.
• To estimate the potential for AWD to enhance global rice production sustainability.

Main Methods:

• Analysis of 1,187 paired field observations comparing AWD and continuous flooding.
• Quantification of AWD effects on yield (ΔY).
• Statistical modeling to determine factors explaining ΔY variation.

Main Results:

• The lowest soil water potential during drying is the primary driver of yield variation under AWD.
• A soil water potential-based AWD strategy could improve water productivity in 37% of global irrigated rice areas.
• Potential benefits are particularly noted for regions like India, Bangladesh, and central China.

Conclusions:

• Implementing soil water potential-based AWD offers a viable strategy for sustainable intensification of rice cultivation.
• This approach can significantly enhance water productivity in major rice-producing regions.
• Findings provide a pathway to address water scarcity in global agriculture.