Abstract

                                When successful sea-water farming is being reported, the old concept of rating the irrigation waters on the basis of total salt concentra- tions and pH values needs a revision. Salinisation and alkalisation problems are mainly concerned with the total salt concentration and the sodium ion concentration. The alkali hazard and salinity hazard of irrigation water indicated by S. A. R. limits and E. C. limits prescribed by U.S. D. A. (1954) have been criticised by Hiemann (1958) and Kanwar (1961). Venkatachalam (1958) pointed out that the irrigation waters have to be studied in conjunction with the soil irrigated. It is observed that rather than the mere concentration of individual ions, the balanced ionic environment plays a vital role in soil-plant relationship. Hence, it is essential to revise the code of classifying irrigation waters, so as to have an efficient utilisation. In the present study, the ionic composition of water along with the irrigated soil is considered for the irrigation waters used in the farms of the Agricultural College, Coimbatore in order to find the suitability of old classifications and also the nature and effect of these waters used in the farms.

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