Mitigating global warming potential while coordinating economic benefits by optimizing irrigation managements in...

Area of Science:

• Agricultural Science
• Environmental Science
• Agronomy

Background:

• China's extensive irrigation practices contribute to water and energy consumption, alongside increased greenhouse gas (GHG) emissions.
• Understanding the economic and environmental trade-offs of different irrigation strategies is crucial for sustainable agriculture.

Purpose of the Study:

• To analyze the impact of various irrigation management techniques on maize economic and environmental benefits.
• To investigate the underlying mechanisms of irrigation effects on crop yield and GHG emissions.

Main Methods:

• A two-year field study comparing rainfed (RF), flood irrigation (FI), and drip irrigation (DI).
• A controlled tube study examining five irrigation treatments to detail mechanistic responses.
• Analysis of grain yield, net ecosystem economic budget, carbon footprint, and global warming potential.

Main Results:

• Drip irrigation (DI) and flood irrigation (FI) significantly increased maize grain yield by 35.7% and 22.1% respectively, compared to rainfed conditions.
• DI and FI enhanced net ecosystem economic budget by 35.6% and 34.2%, while reducing carbon footprint by 12.7% and 7.0%.
• Tube studies showed irrigation increased global warming potential (12.0-32.8%) and yield (44.5-203.9%), but decreased GHG intensity (24.3-57.4%), with topsoil water content being critical for GHG emissions.

Conclusions:

• Soil water content in space and time is the primary driver of yield and GHG emission variations across irrigation managements.
• Drip irrigation optimizes soil water distribution, leading to higher yields and reduced GHG intensity.
• Judicious irrigation management (amount and frequency) is key to improving economic returns and minimizing environmental costs in maize cultivation.