Erosion Control Performance of Improved Soil Management in Olive Groves: A Field Experimental Study in NE Portugal

Abstract

Olive groves rank among the cropping systems facing higher erosion risk in Mediterranean Europe. The adoption of erosion control soil management practices is key for reducing such risk and driving olive production towards sustainability. This field experimental study aimed to quantify the erosion control performance of improved soil management as compared to conventional soil management in olive groves of NE Portugal. The design aimed to compare the effects of introducing no-tillage (NT) to a conventionally managed (T) olive grove and those with complementing ground cover by adventitious species (NS) with a sown cover (S) and comprised four treatments: TNS (reference for conventional), TS, NTNS and NTS. Erosion microplots (4 m2) were installed (two per treatment), recording soil loss, runoff and ground cover in seven erosion events throughout one year. The best erosion control performance was found in NTNS (low-cost improved soil management treatment) with 50% and 85% reductions in soil loss, respectively, in the annual total and in erosion events following large precipitation periods. Plots with adventitious vegetation ground cover performed better in soil loss control than the sown ones. Converting to no-tillage, as compared to sowing herbaceous vegetation to increase ground cover, proved more performant and less hazardous for improving erosion control in olive groves.