Geotextile-mats constructed from Borassus aethiopum (Borassus Palm) and Mauritia flexuosa (Buriti Palm) leaves have the potential to decrease soil erosion. In the U.K., field experiments are being conducted on the effectiveness of palm-mats to reduce soil erosion at Hilton, east Shropshire. Twelve plots (each plot measuring 1.0 x 1.0 m; 6 plots were completely covered with Borassus mats, and the other 6 plots were bare) were established to study the effects of geotextile-mats on splash erosion. Eight runoff plots (10 x 1 m on a 15o slope) were used, with duplicate treatments: (i) bare soil; (ii) grassed, (iii) bare soil with 1 m Borassus-mat buffer zones and (iv) completely covered with Borassus mats. Runoff volume and sediment yield were measured after each substantial storm from 25/03/02-10/05/04 (total precipitation = 1320 mm). Results indicate that palm-mats on bare soil significantly reduced total soil splash erosion by ~50% compared with bare soil (34.2 g m-2; during 10/06/02-09/02/04, total precipitation = 1038 mm). Total runoff from bare plots was 3.58 litres m-2 and total sediment yield was 8.58 g m-2. Borassus mats as buffer strips reduced runoff by ~36% and soil erosion by ~57%. Total soil loss from the completely covered plots was only ~16% less than the buffer zone plots. To confirm the results, another set of runoff experiments are in progress at Hilton, with one additional treatment (bare soil with 1 m Buriti-mat buffer zones) compared with the earlier experiment. Results (08/01/07-24/08/07; total precipitation = 702 mm) indicate that total runoff from bare plots was 21.2 litres m-2 and total sediment yield was 2302 g m-2. Borassus and Buriti mats as 1 m buffer strips reduced runoff by ~86 and 61%, respectively, and soil erosion by ~93 and 98%, respectively. Buffer strips of Borassus mats are as effective as complete cover of the same mats and are more effective in reducing runoff water than the buffer strips of Buriti mats. Combined results from both sets of runoff experiments (total precipitation = 2022 mm) suggest that application of Borassus mats as 1 m protective buffer strips on bare soil reduced runoff by ~77% and soil erosion by ~93%. Thus, Borassus-mat (buffer strips) cover on vulnerable segments of the soilscape is highly effective for soil and water conservation on temperate loamy sand soils.

Previously, most studies on the effectiveness of geotextiles on soil erosion rates and processes were conducted in laboratory experiments for <1 h. Hence, at Hilton (52o33' N, 2o19' W), East Shropshire, UK, we investigated the effectiveness of employing palm-mat geotextiles (Borassus and Buriti mats) to reduce rainsplash erosion, runoff and soil loss under field conditions. This study is a component of the European Union-funded BORASSUS Project. The effects of Borassus mats on rainsplash erosion were studied for ~2 years (2002-2004), and re-established in January 2007 on a 0o slope. There were 12 experimental plots (six plots completely-covered with mats and six bare plots; each measuring 1.0 x 1.0 m). Runoff-plot studies were also conducted on the loamy sand soil at Hilton for 2 years (2002-2004) with duplicate treatments: (i) bare soil; (ii) grassed, (iii) bare soil with 1 m Borassus-mat buffer zones at the lower end of the plots and (iv) completely-covered with Borassus-mats. Each plot was 10 x 1 m on a 15o (26.6%) slope. To confirm the results, another set of experiments have been in progress at Hilton since January 2007, with one additional treatment (bare soil with 1 m Buriti-mat buffer zones) compared with the earlier experiment. Runoff and soil erosion were collected from each plot in a concrete gutter, leading to a 0.02 m3 (20 liters) capacity receptacle placed inside a 0.14 m3 (140 liters) capacity container. Results (06/10/02-02/09/04; total precipitation = 1038.3 mm) showed Borassus mats on bare soil reduced total rainsplash erosion by ~50% compared with bare plots (9.64 kg m-2; 1.97 lb ft-2). The use of Borassus mats on bare soil (during 01/22/07-01/21/08; total precipitation = 919.2 mm) also reduced soil splash erosion by ~90%. During 03/25/02-05/10/04 (total precipitation = 1319.8 mm) complete cover of Borassus mats on bare soil reduced total runoff by ~19% and soil erosion by ~64%. Furthermore, Borassus mats as 1 m buffer strips on bare soil reduced runoff by ~36% and soil erosion by ~57%. During 01/08/07-01/14/08 (total precipitation = 923.4 mm), plots with Borassus and Buriti mats as buffer strips on bare soil reduced sediment yield by ~93 and 98%, respectively, and runoff by ~83 and 63%, respectively. Buffer strips of Borassus mats were also as effective as complete cover of the same mats. Thus, utilization of palm-mat geotextiles as buffer strips on bare plots (area coverage ~10%) is highly effective for soil and water conservation.