Utilizing palm-leaf geotextile mats to conserve loamy sand soil in the United Kingdom

Despite palm-leaf geotextile mats having the potential to advance soil conservation technologies, field studies using geotextiles as complete cover and buffer strips in reducing rates of soil erosion by water are limited. Hence, the utilization of these mats as a potential soil conservation technique is investigated at Hilton, east Shropshire, UK (52°33′5.7″N, 2°19′18.3″W). Geotextile mats constructed from Borassus aethiopum (Borassus palm of West Africa) and Mauritia flexuosa (Buriti palm of South America) leaves are termed Borassus mats and Buriti mats, respectively. Field experiments have been conducted at Hilton since January 2007, to study the effects of emplacing Borassus and Buriti mats on the erosion of a loamy sand soil. Two sets (12 plots each) of experiments were established to study the effects of Borassus and Buriti mats on splash height and splash erosion. In both sets, 6 randomly-selected plots were completely covered with mats, and the rest were bare. Ten runoff plots (10 × 1 m on a 15° slope) were also established, with duplicate treatments to study the effectiveness of these mats for soil and water conservation. The treatments were: (i) bare soil; (ii) permanent grassed; (iii) bare soil with 1 m Borassus mat buffer zones at the lower end of the plots; (iv) bare soil with 1 m Buriti mat buffer zones at the lower end of the plots and (v) completely covered with Borassus mats. Results (during 22/01/07–21/01/08; total precipitation = 919.0 mm; n = 22 sets of measurements) indicate that Borassus mat-cover on bare soil significantly (P < 0.05) reduced total soil splash erosion by ∼90% compared with bare plots (24.81 kg m−2). Plots with Borassus mats had 51% less mean splash height than bare plots (n = 21 sets of measurements). However, Buriti mat-cover on bare soils had no significant (P < 0.05) effect on soil splash height or splash erosion. Results of runoff plots (08/01/07–14/01/08; total precipitation = 923.4 mm; n = 29 sets of measurements) showed permanent grass plots had the smallest runoff coefficient and the largest sediment yield reduction effectiveness (SYRE). Total runoff from the Borassus buffer zone plots (4.1 L m−2) was ∼83% less than the bare plots and total sediment yield was ∼93% less than the bare plots (2.32 kg m−2). Although, Borassus buffer zone plots had similar effects in reducing soil loss to Borassus completely-covered plots, the later treatment yielded ∼50% more runoff. Borassus buffer strip plots had less SYRE than the Buriti buffer zone plots. Mass per unit area and thickness of both geotextiles decreased after 3 months of surface application. However, moisture sorption depth and cover percentage of both geotextiles increased. Hence, it is recommended to cover palm-mat geotextiles as buffer strips for soil and water conservation on erodible moderate slopes.