Agriculture management impacts on soil properties and hydrological response in Istria (Croatia)

The objective of this work is to study the effects of traditional land uses (vineyard, cropland, and olive orchard) on soil properties, overland flow, and sediment loss in the Istria region (Croatia), by using simulated rainfall. The results showed that soil bulk density (BD) was significantly higher in cropland plots compared to the vineyard and olive orchard. No differences were observed in soil water content (SWC) and mean weight diameter (MWD). Water stable aggregates (WSA), soil organic matter (SOM), and total nitrogen (TN) were significantly higher in the olive orchard compared to the other land uses. In cropland, during the experiment, we did not identify runoff or soil losses. Runoff (Run) and sediment loss (SL) were significantly higher in the olive orchard compared to the other plots. This was very likely a consequence of tillage practices in vertic soils, the use of herbicides, low vegetation cover, as well as the incorporation of hydrophobic organic matter in the soil matrix. The principal component analysis results showed that factor 1 explained the majority of the runoff and erosion variables. Erosion rates and nutrient losses were substantially different between olive orchard plots, and vineyard and cropland. Factor 2 showed that WSA was inversely related to the available phosphorus, water holding capacity, and sediment concentration. Management practices in the studied area should use minimum tilling frequency to have plant cover and avoid erosion.