Using palm-mat geotextiles on an arable soil for water erosion control in the UK

Abstract

To date, most studies of the effectiveness of geotextiles on soil erosion rates and processes have been conducted in laboratory experiments for less than 1 h. Hence, at Hilton (52°33′ N, 2°19′ W), UK, the effectiveness of employing palm-mat geotextiles for soil erosion control under field conditions on arable loamy sands was investigated. Geotextile-mats constructed from Borassus aethiopum (Borassus palm ofWest Africa) and Mauritia flexuosa (Buriti palm of South America) leaves are termed Borassus mats and Buriti mats, respectively. Duplicate runoff plots (10 m ¥ 1 m on a 15° slope) had five treatments (bare, permanent grass, Borassus total plot cover, Borassus buffer strip and Buriti buffer strip). Borassus covered plots had about 72% ground cover and to differentiate between this treatment and Borassus buffer strips, the former treatment is termed Borassus completely-covered. Runoff and eroded soil were collected from each bounded plot in a concrete gutter, leading to a receptacle. Results from 08/01/2007 – 23/01/2009 (total precipitation = 1776·5 mm; n = 53 time intervals) show that using Borassus buffer strips (area coverage ~10%) on bare soil decreased runoff volume by about 71% (P > 0·05) and soil erosion by 92% (P < 0·001). Bare plots had nearly 29·1 L m-2 runoff and 2·36 kg m-2 soil erosion during that period. Borassus buffer strip, Buriti buffer strip and Borassus completely-covered plots had similar effects in decreasing runoff volume and soil erosion. Runoff volumes largely explain the variability in soil erosion rates. Although buffer strips of Borassus mats were as effective as whole plot cover of the same mats, the longevity of Borassus mats was nearly twice that of Buriti mats. Thus, use of Borassus mats as buffer strips on bare plots is highly effective for soil erosion control. The mechanisms explaining the effectiveness of buffer strips require further studies under varied pedo-climatic conditions.