Rice

Abstract

This work evaluates how water-saving irrigation — furrow irrigation and tailwater recirculation (alternate wetting and drying) — affects evapotranspiration, water-use efficiency, and ecosystem carbon and water exchange in row rice.

Period of Performance

2025 - PRESENT

Funding Agency

MSU (WRRI)

Lead Scientist

Eddy Covariance

Methods

Six eddy covariance towers at farmer fields measure carbon dioxide, water vapor, and energy fluxes from planting to harvest, combined with satellite remote sensing and machine learning to quantify the ecological footprint of U.S. rice.

Results

Key findings Remotely sensed ET alone correlated only weakly with eddy-covariance ET in rice. ET was strongly driven by meteorology; weather variables explained most of the variation, with remote sensing adding a correction. A random-forest model combining tower and satellite data predicted ET with R² ≈ 0.46 (RMSE 1.18 mm/day); temperature, solar radiation, and humidity were the top predictors. Additional higher-resolution ground data are expected to improve accuracy.