Soil Erosion and the Efficiency of the Conservation Measures in Mediterranean Hillslope Farming (SE Spain)

Abstract— The rainfed mountain plantations in semiarid areas of the Mediterranean region with conventional practices register soil erosion values much higher than soil formation rates, affecting their long-term sustainability. The objective of this study during four-year monitoring period was to evaluate the response of soil erosion and runoff to different soil-management strategies (SMS) for the most representative rainfed fruit crops: almond, olive, and vineyard. The SMS based on conservation agriculture techniques were: minimum tillage, minimum tillage with plant strips, and no-tillage with plant strips. Soil erosion and runoff patterns were examined in erosion plots on a mountain slope under each SMS. The results demonstrated that the SMS investigated reduce runoff and soil erosion compared to conventional tillage in the study area. The combination of minimum tillage with plant strips in almond and vineyard showed to be more valuable strategy in soil control than unique minimum tillage, averaging a reduction of soil erosion and runoff of 36 and 39%, respectively. As for olive, the minimum tillage with plant strips with respect to no-tillage was able to lessen both soil erosion and runoff by 36%. Likewise, this strategy proved to be the most efficient for minimizing the adverse impact of heavy rains on water erosion development on hillslopes. Since an increase of high-intensity rainfalls in the Mediterranean semi-arid areas is expected, the implementation of sustainable strategies is urgent in order to mitigate the effects of climate change.