This study was built to investigate the impact of subsurface drainage on iron toxicity in Tropical Savannah irrigated rice valley bottoms. The research leaned upon two complementary approaches: field investigations and designed experiments. Important results, covering several fields, where achieved. For example, It appeared that single-season irrigation schemes present higher iron toxicity and acidity risks than double-season ones – 750 up to 1800 mg/l of Fe2+ higher in the single-season scheme of Moussodougou than in the double-season scheme of Tiefora. Furthermore, a statistical analysis...