Jimmy Lamo, Rice Breeder at the National Agricultural Crop Resources Research Institute (NaCRRI), Uganda observed in an on-station trial, that the rice seed produced on a plot where sweetpotato had previously been planted had higher seed purity. His curiosity has led to a collaboration with the International Potato Center (CIP) to test rice-sweetpotato rotations in irrigation schemes in northern Uganda. Analysis of the first rotation shows a statistically significant net profit ratio from the rotation of 2.0, compared to 1.8 for the control.