The study compared two methods to measure how much water is used by rice plants as they grow. One method looked at changes in water levels in a field, while the other method used calculations based on heat measurements. The results showed that in 2003, the rice plants used less water compared to the previous year because it was cooler. The two methods gave similar results over 10-day periods, but the peaks in water use occurred at different times. The researchers concluded that improvements are needed in the heat-based method to better estimate water use by the rice plants.