Drip irrigation of apricot orchards in areas with high evaporative demand and low rainfall: accumulative effects on salinization and some soil chemical characteristics

Experiments were carried out in a mature apricot orchard located in Southern Italy and drip-irrigated since its establishment. Soil samples were taken at the beginning (April) and at the end (September) of the irrigation season at various depths below the dripper and between the rows (area not affected by irrigation). Chemical, physical and hydrological analyses were performed on soil samples. Higher values of salinity were measured in the deeper soil layers, the maximum value of about 1,600 µS cm-1 occurring at 130 cm depth in the area below the emitter at the beginning of the irrigation season. A further increase of salinity was observed during the seasonal course of irrigation, as a combined effect of the quality of the irrigation water (1,200 mg L-1 of total salts), soil characteristics (loamy-clay, density 1.72 t m-3 at 130 cm depth), high seasonal water irrigation volumes used and of the low rainfall.