Water Infiltration and Surface Runoff in Steep Clayey Soils of Olive Groves under Different Management Practices

Abstract

When olive groves are cultivated on clayey soils with steep gradients, as in many Mediterranean areas, reducing the runoff and soil erosion rates by adopting proper soil management practices is imperative. A soil cover by pruning residues may represent an alternative to the commonly adopted mechanical tillage. This study evaluates the water infiltration rates and surface runoff volumes in a steep and clayey olive grove of Southern Italy. These hydrological variables are measured at the plot scale under four soil management practices (mechanical tillage, total artificial protection of soil and soil cover with two different rates of vegetal residues). The measurements have been carried out using a rainfall simulator under dry (undisturbed) and wet (that is, on soils disturbed by intense rainfall) conditions. The mechanical tillage leads to lower water infiltration rates and higher runoff production. The retention of a soil cover by vegetal residues (in the range 3.5–17.5 tons/ha of dry matter) reduces the runoff rate on average by 30%, mainly because of the increased soil infiltration rates (over 100%, compared to mechanical tillage). After soil disturbance due to antecedent rainfall, the runoff generation capacity of a soil disturbed by a heavy precipitation significantly increased compared to undisturbed soils because of the decrease in soil infiltration rates. Overall, the retention of vegetal residues over the soil may be advisable to reduce surface runoff generation rates, particularly for saturated soils.

Spatial and Temporal Changes in Infiltration and Aggregate Stability: A Case Study of a Subhumid Irrigated Cropland

“…The final infiltration intensities were lower under seedbed conditions and increased by one order of magnitude under stubble conditions, or almost decreased to zero for Chernozem. Bombino et al [16] also observed a considerable decrease in the final infiltration due to cultivation on clay soils. Effective infiltration is highly affected by the formation of a surface crust and sealing [45], as the surface is flat and the sediment deposits within a few decimeters.…”

“…Theoretically, smart technologies can change the amount and intensity of artificial precipitation in space, depending on the current soil properties, such as infiltration. In practice, further measurements for calibration and validation are required to ensure successful and stable application [16].…”

Analysis of Land Use Change and Its Impact on the Hydrology of Kakia and Esamburmbur Sub-Watersheds of Narok County, Kenya

“…Compacted soil layers have less pore space and limit water movement through the soil profile [35]. A soil covered by vegetation increases infiltration and reduces runoff [36].…”

Special Issue “Soil Hydrology in Agriculture”

“…They conclude that the limiting factor to calibrate and apply such modeling tools is not in the theoretical part, but it is rather the lack of soil structural and hydrologic data. Bombino et al [15] analyzed some hydrological processes, namely, water infiltration and surface runoff at the plot scale on a steep slope under four soil management practices: mechanical tillage, total artificial protection of soil and soil cover with two different rates of vegetal residues. Overall, they concluded that the retention of vegetal residues over the soil may be advisable to reduce surface runoff generation rates, particularly for saturated soils.…”