Qualità fisica del suolo in un’area ad uso agricolo tradizionale della Sicilia centrale

Nella memoria viene valutata la qualità fisica dei suoli di un’area in cui sono presenti usi del suolo a basso impatto tipici della collina interna siciliana. La valutazione è stata effettuata utilizzando i tradizionali indici basati sulla curva di ritenzione idrica, integrati da misure della porosità dinamica effettuate con l’infiltrometro a depressione. Secondo le classificazioni comunemente adottate, condizioni di qualità fisica prossime a quelle ottimali si sono riscontrate solamente nel suolo sottoposto ad avvicendamento colturale e lavorato secondo pratiche tradizionali. Nel rimboschimento, la qualità fisica dello strato superficiale è risultata non ottimale anche come conseguenza del…

Misura della conducibilità idraulica del suolo con l’infiltrometro a depressione a dischi concentrici

Evaluation of soil physical quality under different soil land uses in a small Sicilian watershed

Sustainability of extensive rain fed agriculture needs assessment of land use effects on soil physical and hydraulic properties. Several soil physical quality indices were determined for four adjacent areas in a small Sicilian watershed, that were characterized by a different land use, namely cropland (C), olive grove (O), grassland (G) and eucalyptus plantation (E). Soil texture was similar for the considered areas, even if the no-tilled soils (G and E) showed a higher clay content in the top layer (0-20 cm) than in the lower layer (20-40 cm). The bulk density of the top layer ranged between 1.20-1.43 g cm-3 (C < G < O < E), with significant differences between C and E. In the lower layer,…

A comparison between the single ring pressure infiltrometer and simplified falling head techniques

Testing the relative performances of the single ring pressure infiltrometer (PI) and simplified falling head (SFH) techniques to determine the field saturated soil hydraulic conductivity, Kfs, at the near point scale may help to better establish the usability of these techniques for interpreting and simulating hydrological processes. A sampling of 10 Sicilian sites showed that the measured Kfs was generally higher with the SFH technique than the PI one, with statistically significant differences by a factor varying from 3 to 192, depending on the site. A short experiment with the SFH technique yielded higher Kfs values because a longer experiment with the PI probably promoted short-term swe…

Using static and dynamic indicators to evaluate soil physical quality in a Sicilian area

Both capacitive indicators derived from the water retention curve and dynamic measurements of the flow-weighted mean pore radius, R0, were used to assess the soil physical quality of two agricultural areas (cropland and olive orchard) and two natural areas (grassland and managed woodlot plantation) potentially subject to soil degradation. The overall idea of the study was to investigate whether a dynamic indicator quantitatively derived from hydraulic conductivity measurements could be used to supplement the traditionally applied capacitive indicators retrieved from water retention measurements. According to the available criteria, only the surface layer of the cropland site showed optimal …