Soil Erosion and runoff response to plant-cover strips on semiarid slopes (SE Spain)

Over a four-year period (1997-2000), soil loss and surface-runoff patterns were monitored in hillside erosion plots with almond trees under different plant-cover strips (thyme, barley and lentils) on the south flank of the Sierra Nevada (Lanjaron) in south-eastern Spain. The erosion plots (580 m a.s.l.), located on a 35 per cent slope, were 144 m2 (24 m×6 m) in area. The plant-cover strips, 3 m wide, ran across the slope. The most effective plant cover proved to be thyme, reducing soil loss by 97 per cent and runoff by 91 per cent, compared to bare soil. Barley reduced soil loss by 87 per cent and runoff by 59 per cent, compared to bare soil, while these percentages were 58 per cent and 18 per cent for lentils. Thyme proved 77 per cent more effective than barley and 93 per cent more effective than lentils in reducing soil loss; thyme was also 79 per cent more effective than barley and 90 per cent more than lentil in blocking runoff. The present study demonstrates the effectiveness of plant-cover strips in controlling soil erosion and runoff on sloping agricultural lan