The data and experience from Sri Lanka's South-West Coastal Reclamation, Drainage and Flood Protection Schemes, over a period of 15 years, have revealed five basic requirements for rice-oriented reclamation projects; namely, in wet weather: (1) Controlled flooding, (2) Drainage improvement; and in dry weather: (1) Protection from coastal and inland salinity, (2) Prevention of transitory acid sulfate conditions, (3) Irrigation. An additional requirement is appropriate and acceptable agronomic technology.
There is recent evidence of rice cultivation on actual and/or old acid sulfate soils. The strong soil acidification and temporary inland salinity during droughty weather make irrigation a vital component for coastal rice projects. With appropriate reclamation and use of available agronomic technology the curent low rice yields of less than 1,590 kg/ha could be increased in the range of 2,655 kg/ha to 3,720 kg/ha and the land double-cropped. The unit of development should be individual projects of about 2,250 ha using the "Polder System" of reclamation, within an overall strategy of integrated multiple resource development. With arable land becoming increasingly scarce, development of rice production on coastal low-lying lands would release better drained rice lands for other food and agro-industrial crops.