ABSTRACT
Rice is one of the principal food crops of the semi-tropical/tropical zone. It is distinct from almost other important crops in that it has a well developed internal conduit system for aerating the roots from the parts growing above the ground, which facility allows rice to grow well under anaerobic waterlogged conditions. Rice is therefore usually the crop of choice for (semi) humid tropical lowland plains where waterlogging conditions (high watertables and/or surface ponding) prevail naturally during much of the wet season or may readily be created by the retention of rain within bunded fields and/or by supplying some additional irrigation water. In the hydro-topographically higher or lower parts of the plains that are less suitable for wet rice culture, other cultures (upland rice and deep water/floating rice, see Figure 15.1) may be grown.
