Geotextiles are employed in civil engineering and construction applications to efficiently and economically conserve soil. Palm-leaf geotextiles offer considerable potential to contribute to sustainable development and soil conservation. Their use can promote sustainable and environmentally-friendly palm agriculture, labour-intensive employment and earn hard currency. Ongoing field and laboratory research is investigating geotextile mats manufactured from palm-leaves to evaluate their long-term effectiveness in controlling soil erosion and assess their sustainability and economic viability. Palm-leaf geotextiles are novel and offer new bioengineering solutions to environmental problems. This is achieved through: (i) Promotion of sustainable and environmentally-friendly palm agriculture to discourage deforestation, promote both reforestation and agroforestry and offer a potential for commercial development. (ii) Construction of palm geotextiles to develop into a rural based labour-intensive industry, particularly encouraging employment of socially disadvantaged groups. In turn, this contributes to the stabilization of rural populations, thus decreasing migration to urban areas. (iii) Export of completed palm geotextiles to industrialized countries earns hard currency for rural developing economies, based on the principles of fair trade. (iv) Application of palm geotextiles are especially beneficial for complex engineering problems, as temporary application of geotextiles allows sufficient time for plant communities to stabilize engineered slopes. Investigations suggest palm geotextiles are an effective, cheap and economically-viable soil conservation method, with tremendous potential. Palm geotextiles offer enormous multi-faceted environmental benefits, which include technologies for sustainable plant production, promoting sustainable use of indigenous plants, improved ecosystem management, decreasing deforestation, improved agroforestry and successful and cost-effective geotextile applications in diverse environments. Palm geotextiles improve socio-economic foundations for sustainable development and the benefits for developing countries include poverty alleviation, engagement of disadvantaged groups as stakeholders, employment for disadvantaged groups, SME (small and medium enterprise) development, earning hard currency, environmental education and local community involvement in reclamation and environmental-improvement programmes.

Some 30% of world arable land has become unproductive, largely due to soil erosion. Considerable efforts have been devoted to studying and controlling water erosion. However, there remains the need for efficient, environmentallyfriendly and economically-viable options. An innovative approach has used geotextiles constructed from Borassus aethiopum (Black Rhun Palm of West Africa) leaves to decrease soil erosion. The effectiveness of employing palmmats to reduce soil erosion have been investigated by measuring runoff, soil loss and soil splash on humid temperate soils. Twelve experimental soil plots (each measuring 1.0 x 1.0 m) were established at Hilton, east Shropshire, UK, to study the effects of geotextiles on splash erosion (six plots completely covered with Borassus mats and six non-protected bare soil plots). Soil splash was measured (10/06/02-09/02/04; total precipitation = 1038 mm) by collecting splashed particles in a centrally positioned trap in each plot. An additional field study (25/03/02-10/05/04; total precipitation = 1320 mm) of eight experimental runoff plots (10 x 1 m on a 15o slope) were used at the same site, with duplicate treatments: (i) bare soil; (ii) grassed, (iii) bare soil with 1 m palm-mat buffer zones at the lower end of the plots and (iv) completely covered with palm-mats. Runoff volume and sediment yield were measured after each substantial storm. Results indicate that total splash erosion in bare plots was 34.2 g m-2 and mean splash height was 20.5 cm. The use of Borassus mats on bare soil significantly (P<0.05) reduced soil splash height by ~31% and splash erosion by ~50%. Total runoff from bare plots was 3.58 L m-2 and total sediment yield was 8.58 g m-2. Thus, application of geotextiles as 1 m protective buffer strips on bare soil reduced runoff by ~36% and soil erosion by ~57%. Although total soil loss from the completely covered geotextile plots was ~16% less than the buffer zone plots, total runoff volume from the completely covered plots was ~94% more than the buffer zone plots. Thus, palm-mat (buffer strips) cover on vulnerable segments of the landscape is highly effective for soil and water conservation on temperate loamy sand soils.

Soil erosion by concentrated flow can cause serious environmental damage. Erosion-control geotextiles have considerable potential for reducing concentrated flow erosion. However, limited data are available on the erosion-reducing potential of geotextiles. In this study, the effectiveness of three biological geotextiles in reducing soil losses during concentrated flow is investigated. Hereto, runoff was simulated in a concentrated flow flume, filled with an erodible sandy loam on three slope gradients (13·5, 27·0 and 41·5%). Treatments included three biological geotextiles (borassus, buriti and bamboo) and one bare soil surface. Darcy–Weisbach friction coefficients ranged from 0·01 to 2·84. The highest values are observed for borassus covered soil surfaces, followed by buriti, bamboo and bare soil, respectively. The friction coefficients are linearly correlated with geotextile thickness. For the specific experimental conditions of this study, borassus geotextiles reduced soil detachment rate on average to 56%, buriti geotextiles to 59% and bamboo geotextiles to 66% of the soil detachment rate for bare soil surfaces. Total flow shear stress was the hydraulic parameter best predicting soil detachment rate for bare and geotextile covered surfaces (R² = 0·75–0·84, p < 0·001, n = 12–15). The highest resistance against soil detachment was observed for the borassus covered soil surfaces, followed by buriti, bamboo and bare soil surfaces, respectively. Overall, biological geotextiles are less effective in controlling concentrated flow erosion compared with interrill erosion. Copyright © 2009 John Wiley & Sons, Ltd.

Field and laboratory studies suggest geotextile mats constructed from palm leaves are an effective, sustainable and economically viable soil conservation technique. The three-year (2005-08) EU-funded BORASSUS Project (Contract number INCO-CT-2005-510745) is evaluating their long-term effectiveness in controlling soil erosion and assessing their sustainability and economic viability in 10 countries in Africa, Europe, South America and South-East Asia. The technique offers potentially novel bioengineering solutions to environmental problems, including technologies for soil conservation, sustainable plant production and use of indigenous plants, improved ecosystem management, decreasing deforestation, improving agroforestry and cost-effective geotextile applications in diverse environments. Palm geotextiles may improve socio-economic foundations for sustainable development and the benefits for developing countries may include poverty alleviation, engagement of local people as stakeholders, employment for disadvantaged groups, small and medium enterprise (SME) development, earning hard currency, environmental education and local community involvement in land reclamation and environmental education programmes. These benefits are achieved through: (a) Promotion of sustainable and environmentally-friendly palm agriculture to discourage deforestation, promoting both reforestation and agroforestry; (b) Construction of palm geotextiles developing into a rural labour-intensive industry, particularly encouraging employment of socially-disadvantaged groups; and (c) Export of palm geotextiles to industrialized countries earns hard currency for rural developing economies, based on the principles of fair trade. In Europe, experiments are in progress in diverse field environments (agricultural and archaeological sites, coastal sand dunes and engineered slopes) and in laboratory simulations of both water and wind erosion processes.

Geotextiles constructed from Borassus aethiopum (black rhun palm) leaves are currently being investigated for their effectiveness in decreasing water erosion. The study aims to develop sustainable methods of soil conservation where the material meets selected criteria (readily available, simple and cost-effective to manufacture, provides immediate erosion control and possibly increases soil fertility and organic matter content). Grid mats were manufactured in a cottage workshop in The Gambia, West Africa. They are currently under investigation at the Hilton Experimental Site in Shropshire, UK. Eight runoff plots (10 × 1 m on a 15° slope) are being used, with duplicate treatments: (i) bare soil; (ii) grassed; (iii) bare soil with 1 m palm-mat buffer zones at the lower end of the plots; and (iv) completely covered with palm-mats. Results from one year of field study (2002-03) indicate sediment yield is 36·8 per cent from replicated covered plots and 35·9 per cent from the replicated buffer zone plots, compared to the control bare plots. Sediment yield equated to 0·45 t ha-1 from bare soil, 0·09 t ha-1 from grassed plots and 0·17 t ha-1 from both the covered and buffer zone plots. The results suggest palm-mat application as protective buffer strips is highly effective in temperate climates. Future work is intended to follow this pilot study and develop well-researched guidelines for practical field applications in other global regions, namely Africa, Southeast Asia and South America.

Biogeotextiles constructed from the leaves of Borassus aethiopum and Mauritia flexuosa are investigated at the Kaltinėnai Research Station of the Lithuanian Institute of Agriculture, which is participating in the EU-funded BORASSUS Project. Biogeotextiles are potentially excellent biodegradable and environmentally-friendly materials useful for soil conservation. Field studies on a steep (21–25°) roadside slope in Lithuania suggest biogeotextile mats are an effective and sustainable soil conservation technique. Biogeotextiles have a potential as a biotechnical soil conservation method for slope stabilization and protection from water erosion on steep industrial slopes and may be integrated with the use of perennial grasses to optimize protection from water erosion. The investigations demonstrated that a cover of Borassus and Buriti mats improved the germination and growth of sown perennial grasses. The biomass of perennial grasses increased by 52.0–63.4% under cover of Borassus mats and by 18.6–28.2% under cover of Buriti mats. Over 2 years, the biogeotextiles (Borassus and Buruti, respectively) decreased soil losses from bare fallow soil by 90.8% and 81.5% and from plots covered by perennial grasses by 87.9% and 79.0%, respectively.

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.

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.

Field and laboratory experiments has shown that geotextile mats made from palm leaves are an effective, sustainable and economically-viable soil conservation method, with huge global potential. The EU-funded BORASSUS Project (2005-09; Contract Number INCO-CT-2005-510745) is evaluating the long-term effectiveness of biogeotextiles in controlling soil erosion and assessing their sustainability and economic viability. These experiments are in progress in 10 countries, both in the ‘industrial north’ (in Europe) and in the ‘developing south’ (Africa, South America and South-East Asia). This paper discusses the significance of geotextile palm mats in European countries (Belgium, Hungary, Lithuania and the UK). Geotextile mats were effective in reducing splash erosion, runoff and soil erosion on arable sloping land in Shropshire, UK. The use of Borassus-mats on bare soil reduced soil splash height by ~31% and splash erosion by ~42%. The application of Borassus-mats as complete cover on bare soil reduced runoff by ~49% and soil erosion by ~75%. Borassus and Buriti mats as 1 m buffer strips reduced runoff by ~56 and 34%, respectively, and soil erosion by ~83 and 77%, respectively. Results from selected types of vineyards in Hungary suggest that the geotextile mats are effective in reducing soil erosion, particularly erosive rainfall. The geotextiles mats are also helpful in maintaining moisture and temperature conditions in the surface soil at levels particularly conducive to the establishment and growth of young plants. Experiments in Lithuania show that geotextile mats are effective in encouraging the establishment and growth of natural vegetation, thereby reducing erosion on roadside slopes. Simulated experiments in controlled laboratory conditions in Belgium suggest that palm-leaf geotextiles are effective in increasing infiltration rates and reducing interrill runoff and erosion rates on medium (i.e. 15%) and steep (i.e. 45%) slope gradients. The effectiveness of geotextile mats when used as technical materials for the construction industry in ground strengthening was investigated. Generally, the tensile strength of the Buriti mats was approximately twice that of the Borassus mats. The tensile strength of the palm-leaf geotextile mats is influenced by the mat strip formation pattern. Research and development activities of the BORASSUS Project have improved our knowledge on the effect of palm geotextile mats on the micro- and macro- soil environments and at larger scales through controlled laboratory and field experiments in diverse environments.