Fertility and organic matter in submerged rice soils

Wetland rice systems in Asia make a major contribution \nto global rice supply. The system is also able to maintain \nsoil fertility on a sustainable basis. The essential components of wetland rice culture comprise cultivation of land in the wet or flooded state (puddling), transplanting of rice seedlings into puddled rice paddies, and growing \nthe rice crop under flooding. The land is dry or floodfallowed during the turnaround period between two crops. Following these cultural practices, two or three crops of rice or rice with upland crops in sequence are grown. However, in the present context of increasing freshwater scarcity, there is a case to shift from the traditional way of growing rice to ways that are water-wise. In this context, it is crucial that the benefits of the wetland rice system on soil fertility and productivity are considered. This article examines the benefits of growing rice in flooded conditions on soil fertility and its maintenance.