Soil, phosphorus and organic matter loss by water erosion in revegetated plots with autoctonous shrubs under semi-arid climate

Abstract

Two treatments with shrubs (Atriplex halimus (Ah) and Thymus Zygis (Tz)) were tested on hillsides from central Spain. It was studied the erosion and diffuse contamination by analyzing organic matter content (OM) and phosphorus (P2O5) in soil and sediments. Compared with the control treatment, Ah presented a significant decrease of runoff and erosion, 47% and 24% lower respectively, but Tz showed 12% more runoff and 152% more erosion than control. Enrichment ratios of OM and P2O5 are evident in eroded sedi­ment and also a strong relation between erosion and OM and P2O5 content was found, showing regression equations with high correlation coefficients, R=0.87 and 0.91 respectively.