Quantifying irrigation cooling benefits to maize yield in the US Midwest

Area of Science:

• Agricultural Science
• Climate Change Adaptation
• Remote Sensing

Background:

• Global climate change necessitates adaptation strategies for crop resilience.
• Irrigation is crucial for crop production in water-limited regions.
• Irrigation provides water and evaporative cooling, mitigating heat stress.

Purpose of the Study:

• To quantify the cooling and water supply contributions of irrigation to maize yield benefits.
• To analyze irrigation's impact on land surface temperature and vegetation index.
• To assess irrigation's effectiveness under varying climate conditions.

Main Methods:

• Utilized satellite remote sensing and maize yield data from Nebraska, USA.
• Employed statistical models to differentiate irrigation's effects.
• Paired flux sites were used to measure air temperature changes.

Main Results:

• Irrigation increased maize yields by 81% compared to rainfed crops.
• A cooling effect of -1.63°C on land surface temperature and +0.10 on enhanced vegetation index was observed in July.
• 16% of yield increase was attributed to irrigation's cooling effect, with 84% to water supply and other factors.

Conclusions:

• Irrigation cooling is a significant, non-negligible factor in enhancing crop yields.
• The cooling effect of irrigation is more pronounced under hot and dry conditions.
• Irrigation's cooling benefits may become increasingly important with future climate warming and drought frequency.