In Ceylon, a country whose economy is still essentially agricultural, population pressure demands tke maximum development of its natural resources on sound scientific lines. Of all these natural resources, water is the single asset of maximum bearing on the life and welfare of its inhabitants, and irrigation is one of the main forms in which water resources are utilised for the benefit of man.
In the vast network of irrigation schemes both old and new scattered through the length and breadth of the Island, paddy forms the chief crop irrigated; whatever system of irrigation is adopted, a scientific approach to the determination of the water consumption pattern of the crop irrigated, forms the basis for better irrigation practice and more economical use of water, and this approach would necessarily take into account the characteristics of the soil, plant growth and drainage, amongst other associated subjects.
Actual field test results may vary very widely with controlled laboratory results. Nevertheless both studies are useful in understanding the consumptive and re-use factors.
With a view to dertemining the consumptive and re-usefactors for paddy as obtained in various parts of the island, selected irrigation schemes were taken up for field test studies by the Laboratory Services Division of the Department of Irrigation. The objective of this paper is to evaluate the method adopted in the determination of these factors, and present some of the data obtained so far.
