ABSTRACT
Irrigated paddy rice is one of the world's most productive crops; its cultivation has relatively few adverse effects on the environment. Environmental concerns associated with rice production are restricted mainly to human diseases in irrigation schemes and to increased biocide use. Rice provides the staple food for more than half the world's population. The success of the Green Revolution in increasing rice production, and the convenience value of rice for home consumption, have persuaded many non-Asian developing countries to extend their rice culture. Increased rice from converted mangrove swamps decreases shrimp and fish production offshore-a tradeoff to be addressed before such conversion. Many African areas devoted to hydromorphic rice suffer from fluctuating water tables. Wetland rice cultivation requires accurate land levelling, followed by preparation and maintenance of terraces and bunds to retain flood water. Rice fields can provide ideal habitats for fish rearing, which traditionally has been an important source of protein.
