Study on the quality of irrigation waters

Abstract

The lack of information on the water quality of irrigation waters in the local agricultural industry calls for a dire need to study various parameters of irrigation water. This project was intended to carry out a survey along the Maltese islands to study water quality trends in the Maltese water table. The variations in water quality will be considered not only on topographical and geomorphologic characteristics but also due to the effects of industry, drainage water and livestock in respect to growth of crops and public health. The study will also serve as reference data as to irrigation water quality. Moreover the effects of the parameters studied on the agricultural industry will be discussed in view of the European Union guidelines and limits particularly by studying the possible and major causes of nitrate pollution in groundwater either due to intensive use of fertiliser or from intensive animal husbandry. The survey will be carried out on a representative sample approximately sixty taken from on site sources and considered as agriculturally intense regions will be tested for the following parameters namely: a. Electrical Conductivity- by conductivity meter in terms of total dissolved solids. This was then related with salinity. b. Chlorides- by titrimetry in terms of water salinity and classified accordingly according to USDA classification of irrigation waters. c. Sodium- by or atomic absorption spectrophotometry in terms of groundwater sodicity. Again the data obtained was classified according to sodicity levels. d. Nitrates- by steam distillation as total nitrogen. The levels were then treated with relation to location near farms or polluting sources and on type of irrigation water. e. pH- by a digital pH meter. The pH was studied in relation to nitrate content in waters f. Total hardness - by titrimetry in terms of calcium hardness and magnesium hardness. The samples will be taken from boreholes, surface run off and man made reservoirs. Additionally the samples will be adequately labelled as to site location, point of sampling source, and date when sampled. The tests will be carried out at the public health laboratory at Evans Building Valletta.