Mitigation of soil erosion by planting ground cover almonds: implications for sustainable mountain agriculture

Abstract

The conservation and sustainable management of soil and water resources are some of the biggest challenges in rainfed agricultural systems. During two hydrological years, we have studied the rates of erosion and soil runoff from hillside farming in three types of vegetation: barley (Hordeum vulgare), vetch (Vicia sativa) and thyme (Thymbra capitata), in an extensive planting of almond (Prunus amygdalus). The esperiment was conducted in Lanjaron (Granada, SE Spain) with closed erosion plots of 144 m2 (24 mx 6 m) on a hillside with a slope of 35%. Three meter wide vegetable strips were arranged intermittently and across the slope between rows of almond trees. The records

of erosion and agricultural runoff were significantly lower in plots covered with thyme, in contrast to those recorded with vetch. The effectiveness of the thyme-covered over the barley and vetch ones in controlling erosion and runoff exceeded 69 and 67%, respectively. Cover crops while cutting and stopping the path of surface runoff retained transported sediments and promote their infiltration into the soil. Besides, the remaining runoff with much less energy can reinfiltrate on the ground before being intercepted by the next swath. We have concluded that the combination of growing woody plant and cover stripes represents an efficient model of adaptation to the traditional systems to improve productivity and sustainability of mountain agriculture in semiarid climate.