FIELD-SCALE ASSESSMENT OF NUTRIENT AND SOIL LOSSES DURING SURFACE RUNOFF EVENTS, IN AN OLTREPÒ PAVESE (SOUTHERN LOMBARDY ¿ ITALIAN REGION) VINEYARD HILL.

The aim of my Ph.D. work was to investigate sediment transport and nutrient content in runoff water from an agricultural system. The study was carried out in a representative sites of the Oltrepò Pavese, in Lombardy region (northern Italy) in a vineyard equipped with instruments for measuring volume and rate of runoff and collecting samples to determine the amount of soil loss related to each rainfall event. The site was equipped with a weather station, which included a recording rain gauge. The analysis was done under natural rainfall condition during the period December 2008 - December 2012, in which 15 rainfall events were recorded. The first step of the research was to equip the field plot with a collection system. An in-field runoff multislot collector, exploitable for monitoring nutrients, pesticides and sediments loadings in runoff, was installed in the field and was improved with a home made level reading system able to measure with high temporal resolution, the runoff rate variation. Subsequently every runoff event was investigated. Samples were taken and analysed for quantifying the sediments loaded from runoff event and the nutrient losses from the system. Samples were also analysed with a laser diffraction technique in order to characterize, in natural conditions, the distribution of sediment grain-size transported by rainfall runoff.