The informations available on the irrigated agricultural areas within the lower Mediterranean coastal regions, agree in showing the constant advance of the sea water intrusion and the consequent gradual increase in the salt content of the waters used for irrigation purposes; however, irrigated agriculture in those areas is expanding to such an extent thatjustified perplexities are raised as for the scientific and technical motivations which may account for such a situation.
The project aims at interpreting the existing situation in order to find out a documented justification in the field, and without changing the present cropping and irrigation practices, for a spreading irrigated agriculture where the bad quality of the water used would cause a state of abandonment or deterioration.
The irrigation waters used in the lower Mediterranean coastal regions show a gradual increase in salt content owing to intrusion of sea water into aquifers and sparse and irregular rainfull which is insufficient for the crops and replenishment of the aquifers. The project was set up to interpret the existing situation and to determine practical limits of acceptability for irrigated agriculture using brackish groundwater. Preliminary investigations were made to ensure that the fields selected for data collection purposes were representative of the widest ranging soils, hydrogeological irrigation and crops. Four homogeneous areas were identified, 2 in Italy (the Mola di Bari area and various municipalities in the provinces of Brindisi and Lecce) and 2 in Greece (the llia and the Argos Plains, both in the Peloponnese region). Of the chosen fields, 4 are in Mola (with crops of artichokes and potatoes), 7 in the provinces of Brindisi and Lecce (tomatoes, asparagus, almonds and vines), 12 in the llia Plain (artichokes, lettuce, oranges and manderines) and 2 in the Argos Plain (oranges). Initial results confirmed the different behaviour of clayey and sandy soils in the presence of saline irrigation water. Salinization has not occurred in the more permeable soils of Brindisi and Lecce but is widespread in the clayey soils of the llia Plain, where there are modest yields of the more demanding crops. Exceptional amounts of rain have occurred during the course of this research and caused decreases in salinity.
The research includes periodic chemical and physical analyses of soil and water and a continuous monitoring of agricultural practices in sample fields located in Italy and Greece as well as the development of a simulation programme in order to define the real salinization progress, the economic convenience of agricultural activities and the trend of the natural resources degradation; a methodology of monitoring and evaluation of the processes and their relevant effects will also be finalized.