effectiveness of biological geotextiles for soil and water conservation in different...

land degradation & development

Land Degrad. Develop. 22: 495–504 (2011)

Published online 3 March 2011 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/ldr.1097

EFFECTIVENESS OF BIOLOGICAL GEOTEXTILES FOR SOIL AND WATERCONSERVATION IN DIFFERENT AGRO-ENVIRONMENTS

R. BHATTACHARYYA1*, M. A. FULLEN1, C. A. BOOTH2, A. KERTESZ3, A. TOTH3, Z. SZALAI3, G. JAKAB3,

K. KOZMA3, B. JANKAUSKAS4, G. JANKAUSKIENE4, C. BUHMANN5, G. PATERSON5, E. MULIBANA5, J. P. NELL5,

G. M. E. VAN DER MERWE5, A. J. T. GUERRA6, J. K. S. MENDONCA6, T. T. GUERRA6, R. SATHLER6,

J. F. R. BEZERRA6, S. M. PERES6, Z. YI7, L. YONGMEI7, T. LI7, M. PANOMTARACHICHIGUL8, S. PEUKRAI8,

D. C. THU9, T. H. CUONG9 AND T. T. TOAN9

1School of Applied Sciences, University of Wolverhampton, Wolverhampton WV1 1LY, UK2School of Engineering and the Built Environment, University of Wolverhampton, Wolverhampton WV1 1LY, UK

3Geographical Research Institute, Budapest H-1112, Hungary4Kaltinenai Research Station of the LIA, LT-5926 Kaltinenai, Lithuania

5Agricultural Research Council, Pretoria, South Africa6Federal University of Rio de Janeiro, Rio de Janeiro 21940-590, Brazil

7Yunnan Agricultural University, Kunming 650201, China8Chiang Mai University, Chiang Mai 50200, Thailand

9Hanoi Agricultural University, Hanoi, Vietnam

Received 15 January 2011; Accepted 18 January 2011

ABSTRACT

Available studies do not allow comparison and quantification of the effects of biological geotextiles on runoff and water erosion rates underdifferent agro-environmental conditions. Hence, this paper addresses this issue by comparing runoff and soil loss data obtained from fieldexperiments (using different types of biological geotextiles) conducted in the United Kingdom, Hungary, South Africa, China, Thailand andVietnam. Palm leaf mats (Borassus and Buriti mats) were used in the European countries. In the UK, Borassus mats were used as whole plotcover (area coverage �76 per cent; termed Borassus completely covered to differentiate from the Borassus buffer strip plots) and as bufferzones (area coverage �10 per cent), whereas Buriti mats were used only as buffer zones (area coverage �10 per cent). Only Lala mats wereused in South Africa. Elsewhere (China, Thailand and Vietnam) biological geotextiles were constructed using other indigenous localmaterials, such as bamboo, rice straw and maize stalks. Biological geotextiles were used on bare plots in South Africa and the Europeancountries. In the UK, plots were maintained bare by need based herbicide spraying. However, in South Asia, different crops were grown on thegeotextile-covered plots. Results suggest that biological geotextiles were very effective for soil erosion control in all locations and theeffectiveness for decreasing soil erosion rates by water was in the range of �67–99 per cent. The effectiveness of biological geotextiles inreducing runoff volume was in the range of �26–81 per cent. In the UK, total runoff and soil loss (during 8 January 2007–6 May 2008; totalprecipitation¼ 1145.8 mm) from the Borassus (one metre wide) buffer zone plots (cover percentage �7.6 per cent) were, respectively, �81and�93 per cent less than bare plots. In Hungary and China, plots with�38 and 22 per cent geotextile-cover, respectively, had �88 and 96 percent less soil loss, than bare plots. In most months with low precipitation (depth) in Hungary and the UK, runoff volume was greater from plotswith geotextile-cover than from bare soils. However, complete data sets indicate that in the UK and Hungary, runoff reduction by differenttreatments over bare plots ranged between �26 and 81 per cent. Results from the UK showed that plots with buffer strips of Borassus andBuriti mats had similar effects in reducing soil losses as completely covered plots of the Borassus mats. Thus, foreseeing biological geotextile-cover on vulnerable segments of the landscape is highly effective for soil erosion control. Copyright # 2011 John Wiley & Sons, Ltd.

key words: biological geotextiles; palm-mat geotextiles; buffer strips; reduction in sediment yield; runoff volume; different environments

INTRODUCTION

Geotextiles (sometimes termed rolled erosion control

systems) have enormous global potential for soil and water

conservation. Geotextiles are defined as ‘permeable textiles

* Correspondence to: R. Bhattacharyya, Scientist, Vivekananda Institute ofHill Agriculture (Indian Council of Agricultural Research), Almora, Uttar-akhand 263601, India.E-mail: [email protected]

Copyright # 2011 John Wiley & Sons, Ltd.

used in conjunction with soil, foundation, rock, earth or any

geotechnical engineering-related material’ (John, 1987).

Erosion control geotextiles are made from natural (jute, coir,

sisal, cereal straw and palm leaves) or synthetic (nylon,

polypropylene, polyester and polyethylene) materials

(Rickson, 2006). Geotextiles create a stable, non-eroding

environment and, if constructed using indigenous materials,

they could be effective, affordable and compatible with

sustainable land management. Biological geotextiles can

496 R. BHATTACHARYYA ET AL.

serve as a temporary replacement of the vegetative cover on

steep erodible slopes, where vegetative growth is limited by

erosive forces of rain and runoff (Smets et al., 2007). Thus,

they have the potential to effectively conserve soil on

sloping lands, which may be agricultural land or engineered

slopes (such as road embankments or dam walls).

The presence of biological geotextiles on slopes reduces

runoff volume in several ways: (i) surface runoff is divided

into several smaller paths, due to the numerous obstructions

caused by the presence of matting, thus decreasing the

overall damaging impact of flowing water; (ii) furthermore,

the geotextile nets increase infiltration with their saturation

and reduced flow of water by creating a network of small

microdams, which further increases infiltration (Langford

and Coleman, 1996; Sutherland and Ziegler, 1996). In

addition, (iii) the surface cover of geotextiles provides

surface roughness, retards overland flow velocities and alters

the shear stress partitioning of overland flow (Thompson,

2001; Leonard and Richard, 2004).

Use of biological geotextiles reduces soil loss rates

mainly by providing a surface cover. Soil and climatic

conditions played major roles in the effectiveness of

biological geotextiles for soil erosion control. Apart from

these factors, the effectiveness of biomats in decreasing soil

erosion mainly depends on several biological geotextile

properties, such as per cent open area, mass per unit area,

thickness, tensile strength, mass of mats per unit area when

they are wet, design and drapability (Ogbobe et al., 1998;

Rickson, 2006; Vishnudas et al., 2006; Sutherland and

Ziegler, 2007). As geotextiles become wet they expand to

the soil surface, enhancing drapability (adherence to surface

microtopography) and, hence, controlling runoff and erosion

(Sutherland and Ziegler, 1996). Despite reducing the amount

of splash erosion (Bhattacharyya et al., 2008, 2009, 2010a),

the presence of biomats on slopes controls surface erosion in

several ways: (i) they keep soil and seeds in place and

thereby increase the opportunities for germination and

vegetation growth (Pillai, 1994); (ii) mats may significantly

alter flow direction by creating several cross-drains

(Bhattacharyya et al., 2010b). The rate of sediment transfer

to cross-drains is reduced due to infiltration and reduced flow

speed and total flow volume. It is expected that reduced flow

velocities will lead to sediment deposition behind the small

microdams. Wet networks of mats should then bind recently

deposited sediment, hence effectively conserving soil on site

(Bhattacharyya et al., 2009).

Biological geotextiles constructed from Borassus aethio-

pum (black rhun palm of West Africa), Mauritia flexuosa

(Buriti palm of Latin America) and Hyphaene coriacea

(Lala palm of South Africa) leaves are termed Borassus,

Buriti and Lala mats, respectively. These mats are readily

available in their local area, simple and cost-effective to

manufacture and provide immediate erosion control (Davies


et al., 2006). If harvested correctly, these resources are

highly sustainable and readily available. The mats can be

constructed at an economically viable price of s0.25–0.40

per square metre, which is comparable to other geotextiles

(Davies et al., 2006). These mats also have the potential of

reuse after one or two seasons in temperate climatic

conditions.

In China, palm (Trachycarpus excelsu), maguey (Agave

americana), bamboo (Phyllostachys spp.), sisal (Agave

houllet), ramee (Boehmeria nivea) and jute (Corchorus

capsularis) are some of the main plant species that are used

for manufacture of biological geotextiles. The most effective

strategies to control soil erosion in northern Thailand

include vetiver grass (Vetiveria nemoralis A. Camus) strips,

alley cropping, and contour ridge cultivation with plastic

sheet and straw mulching (INCOPLAST¼ Integrated

Contour with Plastic and Straw Mulch Treatment) when

compared to the other contour cultural practises (Panomtar-

anichagul and Fullen, 2003). INCOPLAST does not always

harvest rainwater effectively, due to water impedance by

plastic sheets, decreased infiltration of rainfall to the soil

profile and high runoff under high rainfall intensity

(Panomtaranchagul et al., 2001). Furthermore, in the

long-term, INCOPLAST may induce serious environmental

problems if partially degradable polythene sheets are

unavailable. Therefore, using biological geotextiles for

surface mulching on sloping land should, potentially, be one

of the most effective methods to increase rainfall accession

into the soil profile, by reducing runoff and soil loss under

intense rainfall. Use of palm-mats for reducing soil erosion

in the northern highlands of Thailand is limited due to the

lack of palm trees (Caryota mitis Lour). However, imperata

grass (Imperata cylindrica) and bamboo (Arundinaria

gigantea) are widely distributed and fast growing in the

highlands. Using imperata grass panels and bamboo mats as

biological geotextiles are expected to effectively control soil

erosion and improve crop water use efficiency in Thailand.

In Vietnam, biological geotextiles constructed from maize

stalks and bamboos were used for soil conservation.

Although biological geotextiles have the potential for soil

erosion control, field studies on quantification of the

effectiveness of biological geotextiles in reducing soil

interrill erosion rates are inadequate. Limited data exist on

the effectiveness of different biological geotextiles in

reducing runoff volume and soil erosion (Sutherland,

1998a, 1998b; Rickson, 2006), especially under different

agro-climatic conditions. Moreover, in many of the studies

reviewed by Rickson and Vella (1992) and Sutherland

(1998a, 1998b), most studies were conducted under

simulated rainfall in laboratories. Hence, the hypothesis

that biological geotextiles are effective in decreasing water

erosion rates needs to be validated using field studies

conducted under a wide range of agro-environmental

LAND DEGRADATION & DEVELOPMENT 22: 495–504 (2011)

ats

Mai

zest

alk

mat

s

zasativa

)M

aize

(Zea

mays

)st

alk

23

50

�0.5

0�

0.5

0V

aria

ble

,�

40�

40

1426

NA

mab

leS

tiff

,not

def

orm

able

BIOLOGICAL GEOTEXTILES CONSERVE SOIL AND WATER 497

conditions. Therefore, the objective of this paper is to

demonstrate and compare the effectiveness of different

biological geotextiles in reducing runoff volume and soil

loss rates under diverse soil and climatic conditions (parts of

Europe, South Africa and South Asia) based on field based

experimental studies. The effectiveness of biological

geotextiles was investigated in combination with grasses

or crops growing through or between the geotextiles. Only

in the UK, regular herbicide sprayings were performed to

maintain the plots bare.

Tab

leI.

Sel

ecte

dp

hy

sica

lp

rop

erti

eso

fth

en

atu

ral

mat

s

Nam

eB

ora

ssus

mat

sB

uri

tim

ats

Lal

am

ats

Bam

boo

mat

sR

ice

stra

wm

Mat

eria

lS

trip

sof

Bora

ssus

pal

m(B.aethiopum

)le

aves

Fib

res

of

Buri

tipal

m(M

.flexuosa

)le

aves

Str

ips

of

Lal

apal

m(H

.coriacea

)le

aves

Str

ips

of

Bam

bo

o(A.gigantea

)S

traw

of

rice

(Ory

Mea

nth

icknes

s(m

m)

16

12

NA

71

3S

ize

(m�

m)

�0.6

0�

0.6

0�

0.5

0�

0.5

0�

0.5

0�

0.5

0�

0.5

0�

0.5

0�

0.5

0�

0.

Mes

hsi

ze(m

m�

mm

)3

0�

30

40�

40

40�

40

40�

40

Mas

sper

unit

area

(gm

�2)

950

520

1332

600

800

Mois

ture

sorp

tion

dep

th(m

m;�

SD

)0.2

8(�

0.0

7)

0.2

2(�

0.0

3)

NA

NA

NA

Def

orm

atio

nan

dben

din

ghar

acte

rist

ics

Sti

ff,

def

orm

able

Fle

xib

le,

def

orm

able

Sti

ff,

def

orm

able

Sti

ff,

not

def

orm

able

Fle

xib

le,

def

or

NA

indic

ates

info

rmat

ion

no

tav

aila

ble

.

MATERIALS AND METHODS

Measurement of Selected Physical Properties of the

Biological Geotextiles

Selected physical properties of several biological geo-

textiles used under diverse soil and climatic conditions

are reported in Table I. Physical properties of mats (size,

thickness, mesh size, mass per unit area and per cent open

area) were analysed in the laboratory taking six randomly

selected samples of biological geotextiles. Mean moisture

sorption depth (MSD) was based on 10 randomly selected

samples with dimensions of 15 cm� 15 cm wetted for 24 h,

followed by 5-min drainage on a wire mesh. MSD was

calculated using the following equation (Sutherland,

1998a):

MSD ðmmÞ ¼ Mass of sorbed water ðkgÞ � C

Area of geotextile ðm2Þ (1)

where C is a conversion factor in millimetres.

Sorption is important in the early stages of a storm,

even prior to saturation, as it influences runoff, infiltration,

evaporation and splash erosion. Selected chemical

properties of the unused mats along with their ageing

effects are presented elsewhere (Kugan and Sarsby, this

issue).

Study Areas

Six field sites in Africa, South Asia and Europe forming

part of the BORASSUS Project, include the Hilton

Experimental Site (Shropshire, UK), the Abaujszanto

Experimental Site (Hungary), the Potshini Experimental

Site, KwaZulu-Natal (South Africa), the Bantuan Exper-

imental Site (Chiang Mai Province, Thailand), the Huong

Non Experimental Site (northern Vietnam) and the

Experimental Farm of Yunnan Agricultural University

(Yunnan Province, China). Soil and climatic data of

these different Experimental Sites are shown in Table II,

while topography and land use data are summarized

in Table III. In this paper, the reported data from South

Africa were from the field plots located on pasture.

Copyright # 2011 John Wiley & Sons, Ltd. LAND DEGRADATION & DEVELOPMENT 22: 495–504 (2011)

Tab

leII

.S

oil

(0–10

cm)

and

clim

atic

dat

aof

the

exper

imen

tal

site

san

dfr

equen

cyo

fdat

aco

llec

tion

Countr

yP

arti

cle

size

dis

trib

uti

on

(US

DA

syst

em)

Soil

textu

reS

oil

org

anic

mat

ter

(per

cent)

Aggre

gat

est

abil

ity

(per

cent)

Infi

ltra

tion

rate

(mm

h�

1)

Mea

nso

ildep

th(c

m)a

Mea

nan

nual

pre

cipit

atio

n(m

m)

Runoff

and

soil

loss

mea

sure

men

t

San

d(p

erce

nt)

Sil

t(p

erce

nt)

Cla

y(p

erce

nt)

Per

iod;

tota

lpre

cipit

atio

n(m

m)

Fre

quen

cy/t

ota

lnum

ber

of

sets

of

mea

sure

men

ts

UK

(5283

30 5

.700 N

,281

90 1

8.3

00 W)

54.4

41.9

3.7

Loam

y-s

and

3.7

473.2

58

120

648

8Ja

nuar

y2007–6

May

2008;

1145.8

mm

Wee

kly

/36

Hungar

y(4

881

60 4

300 N

2181

10 1

500 E

)N

AN

AN

AS

ilt-

loam

1.4

0N

A2.5

>200

597

1Ju

ne

2006–30

Apri

l2

00

8;

98

5.2

mm

Even

t/N

A(d

ata

mea

sure

dfo

r23

month

s)S

outh

Afr

ica

(2884

80 4

5.7

00 S,

2982

10 5

6.7

00 E)

65.0

21.7

13.3

San

dy-l

oam

0.9

74

.5>

150

896

15

Sep

tem

ber

20

06

–1

4D

ecem

ber

20

06

,1

6F

ebru

ary

2007–29

Mar

ch2007

and

11

Januar

y2

00

8–

27

Apri

l2008;

812

mm

Dai

ly/N

A

Ch

ina

(2485

80 3

600 ,

10284

00 1

000 )

NA

NA

NA

Loam

3.0

NA

NA

90

NA

1Ja

nuar

y–31

Oct

ober

20

07

;92

6.7

mm

Wee

kly

/NA

Vie

tnam

(NA

)67.7

16.1

16.2

NA

1.6

4N

AN

A110

1475

1A

ugust

–30

Sep

tem

ber

20

06

;59

1m

mE

ven

t/N

A

Thai

land

(1883

10 0

500 ,

9881

70 3

000 E

)N

AN

AN

AS

andy

clay

loam

5.1

965.0

102

85

NA

9M

ay–5

Novem

ber

20

06

;15

50

mm

Even

t/2

6

NA

indic

ates

info

rmat

ion

no

tav

aila

ble

.an¼

3.



Tab

leII

I.T

op

og

rap

hy

and

lan

du

sed

ata

of

the

exp

erim

enta

lsi

tes

Sit

esT

opogra

phy

Pre

vio

us

land

use

(duri

ng

the

last

10

yea

rs)

Outl

ine

of

the

sow

ing/h

arves

t-in

gof

the

crops

and

inst

alla

-ti

on

of

the

mat

s

Are

aco

ver

age

(per

cent)

of

mat

sC

rop/c

rops

gro

wn

Dom

inan

tgra

ssan

d/t

ree

sp.

Cro

pca

no

py

and

or

gra

ssco

ver

(per

cen

t)S

lop

e(p

erce

nt)

Plo

tsi

ze(m

2)

Ro

ckco

ver

(per

cent)

Hil

ton,

UK

25

10

<10

Bar

e,B

ora

ssus

and

Buri

tico

ver

edplo

tsw

ere

use

din

term

it-

tentl

yfo

rer

osi

on

contr

ol,

new

lyco

nst

ruct

edplo

tsw

ere

per

man

ent

gra

ssed

plo

ts

Aft

erro

tati

on

and

rakin

g,m

ats

wer

eem

pla

ced

on

the

soil

surf

ace

usi

ng

met

alpeg

s

Bora

ssus

com

ple

tely

cover

edplo

ts¼

76,

Bora

ssus

buff

erst

rip

plo

ts¼

7.6

,B

uri

tibuff

erst

rip

plo

ts¼

4.4

No

ne

Am

ixtu

reo

fLolium

perenne,

Phleum

pratense

and

Trifolium

repens

Com

ple

tely

cover

edan

dbuf-

fer

stri

pplo

tsw

ere

mai

nta

ined

bar

eby

regula

rher

bic

ide

spra

yin

g,

inper

man

ent

gra

ssplo

ts�

100

per

cent

cover

Hungar

y20

20

39

Thre

edif

fere

nt

land

use

syst

ems:

young

orc

har

d,

trad

itio

nal

vin

eyar

dan

des

pal

ier

vin

eyar

d

On

the

cover

edplo

ts,

the

low

erhal

fof

the

soil

surf

ace

was

cover

edby

mat

s

38

per

cent

None

Gra

ssco

ver

�0

per

cent

Gra

ssco

ver

�0

per

cent,

Vin

eyar

dan

dorc

har

dco

ver

yea

rro

und

South

Afr

ica

�5

55

0P

astu

reM

ats

wer

eput

on

the

soil

surf

ace

40

No

ne

No

ne

No

ne

Ch

ina

36

28

NA

Tobac

co,

mai

zean

dw

hea

tw

ere

the

mai

ncr

ops

cult

ivat

edin

upla

nd

area

s

Mat

sw

ere

put

on

the

soil

surf

ace

afte

rla

nd

pre

par

atio

n.

See

ds

of

dif

fere

nt

crops

wer

eso

wn

foll

ow

ing

thei

rsp

acin

g

43

Mai

ze(Z.mays

)N

AG

rass

cover

�0

per

cen

t(a

sre

gula

rhan

dw

eedin

g)

Vie

tnam

26

100

0S

oybea

n(G

lycine

max)

and

mai

ze(2

00

per

cent

croppin

gin

tensi

ty)

Mat

sw

ere

put

on

the

soil

surf

ace

afte

rla

nd

pre

par

atio

n.

See

ds

of

dif

fere

nt

crops

wer

eso

wn

foll

ow

ing

thei

rsp

acin

g

67

Mai

ze(Z.mays

)N

AG

rass

cover

�0

per

cen

t(a

sre

gula

rhan

dw

eedin

g)

Thai

land

70

150

0M

aize

and

upla

nd

rice

(200

per

cent

croppin

gin

tensi

ty)

Mat

sw

ere

put

on

the

soil

sur-

face

afte

rla

nd

pre

par

atio

n.

See

ds

of

dif

fere

nt

crops

wer

eso

wn

foll

ow

ing

thei

rsp

acin

g.

Mai

ze(Z.mays

),upla

nd

rice

(O.sativa

)an

dla

bla

bbea

n(Lablabpurpureus)

wer

eso

wn

wit

h400

mm�

750

mm

spac

ing

under

each

trea

tmen

tduri

ng

10–15

May

,05–10

July

and

10–15

Sep

tem

ber

2006,

resp

ecti

vel

y

55

The

annual

mult

iple

crops

are

rota

tions

of

swee

tco

rn(Z.mays

L.)

foll

ow

edby

upla

nd

rice

(O.sativa

L.)

and

labla

bbea

n(L.purpureus

L.)

duri

ng

the

earl

y,m

id-l

ate

and

late

sum

mer

rain

yse

ason,

resp

ecti

vel

y

The

alle

ycr

oppin

ghed

ger

ow

sco

nsi

sted

of

mix

edfr

uit

-tre

es[m

ango

(Mangiferaindica

L.)

,le

mon

(Citrus

aurantifolia

)an

dju

jube

(Zizyphus

jujuba

Mil

l)]

and

gro

und

cov

erw

ith

Gra

ham

stylo

(Stylosanthes

guianensis)

Gra

ssco

ver

�0

per

cen

t(a

sre

gula

rhan

dw

eedin

g)

NA

indic

ates

info

rmat

ion

no

tav

aila

ble

.




Measurement of Runoff Volume and Soil Loss Rates

Runoff volume and soil loss rates were measured at all

experimental stations. At Hilton, runoff volume was measured

to the nearest millilitre, while soil loss was measured (g) by

weighing containers, oven-drying the runoff overnight at

408C, then reweighing the containers. This was performed

regularly, usually every day/week or after a substantial storm

(event based), as mentioned in Table II. Values of total

precipitation received during the reported experimental period

at different field sites are also given in Table II. Generally at all

sites, runoff volume and soil loss rates were collected in a

receptacle placed within a large tank.

In the UK, buffer zone plots (area coverage �10 per cent)

of Borassus and Buriti mats were established to test their

effectiveness compared with Borassus completely covered

plots. Vegetated filter strips (VFS) were first developed in the

1960s to control sediment discharge from agricultural fields

(Dillaha et al., 1989). Munoz-Carpena et al. (1999) defined

VFS ‘as areas of vegetation designed to remove sediment

and other pollutants from surface water runoff by filtration,

deposition, infiltration, adsorption, absorption, decompo-

sition and volatilization’. Davies et al. (2006) also used non-

vegetated buffer strips (1 m geotextile cover at the lower end

of a 10 m long bare plot) as a barrier to the transport of

sediments. Several short-term studies have concentrated on

evaluating the effectiveness of grass filter strips in trapping

sediment and nutrients (Daniels and Gilliam, 1989; Dillaha

et al., 1989; Maggette et al., 1989). However, the use of non-

vegetative buffer strips for effective sediment interception

has not been widely studied.

In the UK, plots were bordered with wooden planks, with

10 cm intruding into the soil and 10 cm protruding above the

soil. Runoff and soil loss data were collected from each plot

in a concrete gutter, leading to a 20 L capacity bucket placed

inside a 140 L capacity container. The sediment collected in

the tray gutters and in the concrete outlets of the central

runoff plots was included by brushing it into the collecting

systems prior to each measurement, as it had been eroded

from the plots.

Runoff volume and soil loss measurements were carried

out by a system developed by the Hungarian team in the

Abaujszanto Experimental Site. At the lower end of the plots

two runoff collectors were installed and connected by a 1:9

divisor. The upper tank (60 L capacity) was designed to

capture 100 per cent of eroded sediment. If the runoff

amount was >60 L, the surplus flowed towards the next tank

(200 L capacity). The divisor between the two tanks led

away 90 per cent of the runoff water, so that 10 per cent of

the amount >60 L was collected in the second, larger

collector tank. The system was, thus, suitable for the

measurement of a theoretical precipitation of at least

100 mm (if zero infiltration was assumed).


In South Africa, runoff water from each plot was collected

in a tipping bucket, which is connected to a data logger.

Once the bucket was full, it was emptied into a drainage

trench and the data logger recorded a dipping as well as the

exact dipping time and, accordingly, the amount of runoff

from the plot. Nine buckets were emptied into the trench,

while the tenth bucket was emptied into a drum. The water in

the drum was stirred vigorously to disperse any soil that may

have settled and a specific amount of water was then

collected from this drum, allowed to dry and then the amount

of sediment was weighed.

Calculation of Runoff and Soil Loss Reduction

Effectiveness

The effectiveness of several biological geotextiles for soil

and water conservation was determined by calculating

runoff reduction effectiveness (RRE) and soil loss reduction

effectiveness (SLRE). RRE and SLRE were calculated

following Sutherland (1998a):

RRE ¼ 100

� Bare runoff ðL m�2Þ�Geotextile cover ROC ðL m�2ÞBare ROC ðL m�2Þ

(2)

where ROC¼ runoff coefficient.

Runoff coefficient ¼ 100

� Volume of runoff ðmm depthÞVolume of rainfall ðmm depthÞ

SLRE ð%Þ ¼ 100

� Bare sediment yield ðg m�2Þ�Geotextile cover sediment yield ðg m�2Þ

Bare sediment yield ðg m�2Þ (3)

It was understandable that the comparisons among the

study areas might be flawed mainly because of different plot

sizes, soil and topography variations in different locations

and method differences. Hence, SLRE was calculated to

cancel out these differences.

RESULTS

Effectiveness of Biological Geotextiles on Runoff Volume

Runoff values of bare plots and RRE (calculated to compare

results from different time scales) of several biological

geotextiles tested in various field plots are shown in Figure 1.

A total of 10 treatments differing in soil and climatic

conditions are studied in this paper. The mean RRE values

range between �26 per cent (for Borassus buffer strip plots

in an orchard in a silt loam soil of Hungary) and �81 per cent


Figure 1. Mean runoff reduction effectiveness (RRE; per cent) of differenttreatments at diverse experimental sites (percentage values after eachtreatment indicate cover percentage). Bars indicate RRE values of differentexperimental sites of: UK, United Kingdom; SA, South Africa; H, Hungary;

T, Thailand; C, China. Error bars indicate standard errors.Figure 2. Mean soil loss reduction effectiveness (SLRE; per cent) ofdifferent treatments at diverse experimental sites (percentage values aftereach treatment indicate cover percentage). Bars indicate SLRE values ofdifferent experimental sites of: UK, United Kingdom; V, Vietnam; H,

Hungary; T, Thailand; C, China. Error bars indicate standard errors.


(for Borassus buffer strip plots in a loamy sand soil of the

temperate UK). Results from individual studies show that

during the experimental period in the UK, the Borassus

buffer strip plots received the least total runoff volume and,

thus showed the highest RRE values (Figure 1). Total runoff

volume from the Borassus buffer zone plots (�4.8 L m�2)

was �32, 48 and 81 per cent less than those of the

completely covered Borassus, Buriti buffer zone and bare

plots, respectively. Thus, Borassus buffer zone plots had

higher RRE values than the completely covered Borassus

plots and as the buffer zone plots with Buriti mats. Likewise,

the application of Lala-mats led to slightly increase runoff

volumes in South Africa. The results obtained from Thailand

during the 2006 rainy season show that Bamboo mats

reduced runoff depth to 50 per cent (Figure 1). Results from

China indicate that the effects of different treatments on soil

erosion control followed the sequence: rice-straw comple-

tely covered plots <rice-straw buffer strip plots (area

coverage �22 per cent) <bare plots.

Effectiveness of Biological Geotextiles on Soil Loss

For all field plots, bare plots have higher soil loss values than

mat covered plots (Figure 2). To compare results among

plots under several treatments, SLRE was calculated. The

SLRE values ranged from �67 per cent for plots completely

covered by Bamboo mats in Vietnam to �99 per cent for

Borassus completely covered plots in the UK (Figure 2). In

the UK, SLRE values for the Borassus and Buriti buffer zone

plots were �93 and 98 per cent, respectively. Although both

Borassus completely covered plots and Borassus buffer strip

plots had similar SLRE values, total runoff from the

Borassus buffer zone plots was less than that of the

completely covered plots with the same mats. This indicates

that use of 1 m buffer zones of Borassus mats on bare plots


was very effective for soil erosion and runoff control. In

Hungary, the amount of soil loss usually was <0.01 Mg ha�1

(1 g m�2) following rainfall intensities ranging between 5.4

and 29.4 mm h�1. As the highest difference in sediment

yield between covered and uncovered plots was usually on

the orchard and the lowest on the traditional vineyard (data

from only orchard is presented here). In Brazil, completely

covered Buriti plots had a SLRE value of �93 per cent. It is

noteworthy that even in China, �22 per cent cover of rice-

straw mats at the lower end of the plots had similar SYLE

values as compared to plots with �43 per cent cover by the

same mats. Bamboo mats on bare soils significantly

(p< 0.05) reduced soil loss as compared to plots with

contour ploughing in Thailand. In Vietnam, application of

all biological geotextiles, namely Borassus, maize stalk and

bamboo mats, was highly effective in reducing soil loss

(Figure 2), whereby the SLRE of maize stalk mats was the

highest (�98 per cent).

DISCUSSION

Effects of Biological Geotextiles on Runoff Volume

The large range of RRE values among all field sites can be

attributed to the variations in biological geotextile cover

percentage and their interaction with different environmen-

tal factors and mode of use. Biological geotextiles on bare

soil reduced runoff under different soil and climatic

conditions. This is perceived to be due to the fact that in

general biological geotextiles behave like mulching

materials in reducing runoff depths (Smets et al., 2007).

However, in compact soils, retarding runoff velocity could



increase surface ponding (rather than infiltration). This

might increase runoff volumes.

Similar to the results of these studies, Sutherland and

Ziegler (2007) reported that geotextiles significantly

(p< 0.05) delayed time to runoff generation and increased

infiltration compared to the bare treatments. However, along

with surface cover, slope gradient and rainfall intensity also

play major roles in determining infiltration rates (Poesen,

1984; Janeau et al., 2003) and the effectiveness of biological

geotextiles (Bhattacharyya et al., 2009). In a laboratory

study, Smets et al. (2007) found that Borassus and Buriti

mats were more effective in reducing runoff coefficients (by

�76–18 per cent) on a medium (15 per cent) slope compared

with a steep (45 per cent) slope. In contrast, Davies et al.

(2006) found higher runoff on plots completely covered by

Borassus mats as compared to bare plots. This was mainly

attributed to low precipitation amounts (<50 mm week�1) at

Hilton, during the experimental period (2002–2004). When

rainfall intensity was low, the per cent of raindrops rolling

over the mats and discharging as runoff without direct

contact with soil may have been higher than that under high

rain intensity. The very low RRE values (�26 per cent) from

the Borassus buffer zone plots in Hungary can also be

attributed to very low rainfall intensities.

Effectiveness of Biological Geotextiles on Soil Loss

Earlier field experiments in the UK, set up to compare the

effectiveness of different treatments in controlling sediment

yield, revealed that jute-nets and jute-mats had only 1.4 and

1.1 per cent of the sediment yield from bare plots,

respectively (Mitchell et al., 2003). The results of the

present study in the UK also showed that buffer strips of

Borassus mats significantly (p< 0.05) reduced soil loss

compared with bare soil and are as effective as complete

cover with the same mats. Notwithstanding physical

protection and sediment entrapment, buffer zones of

Borassus mats may also alter flow direction at the lower

end of the plots. In a study of vegetative buffer strips used in

UK agriculture, surface runoff was reduced by a factor of six

and soil loss was effectively eliminated (Jones, 1993).

Although Buriti mats had no significant effect (p> 0.05) in

reducing both splash erosion and splash height in the UK

(Bhattacharyya et al., 2010a), both buffer strips of Buriti and

Borassus mats had similar effects in reducing soil loss by rill

and interrill soil erosion. The higher drapability might have

offset some of the physical disadvantages of Buriti mats

(such as less mass per unit area, reduced thickness and more

per cent open area) over Borassus mats. The good

drapability factor of Buriti mats (due to their flexibility)

may have allowed them to attach closely to the terrain.

Moreover, the ability to follow the slope contours allowed to

stay in intimate contact with the soil.


In Hungary, Borassus mats were effective tools against

soil loss, particularly during intense precipitation events

causing high runoff. The results suggest that the biological

geotextiles have a good buffering effect on soil temperature

change, especially in the critical very warm periods in

Hungary. However, it was also observed in Hungary that the

plots with Borassus mats had more fungal infestation than

bare plots. Hence, because of plant health requirements, the

use of Borassus mats is not recommended under Central

European climatic conditions.

Less soil loss in the plots under Bamboo mats in Thailand

and Vietnam confirms the importance of retaining surface

cover on sloping land, even if crops were grown. In South

Africa, Lala mats cover �40 per cent of the soil surface and

have a water retention capacity of 1.8l kg m�2. In a dry

season with limited rainfall, biological geotextiles effec-

tively conserve soil moisture at Budapest, Hungary (Kertesz

et al., this issue). Among three tested types of biological

geotextiles maize geotextiles perform best in terms of

moisture conservation.

Smets et al. (2007) observed that both Borassus and

Buriti mats significantly (p< 0.05) decreased inter-rill soil

loss compared with bare soil on 15 and 45 per cent slopes

during 45 and 67 mm h�1 rainfall intensities. Thus, these

mats have tremendous potential for non-agricultural use

where soil surfaces need to be stabilized and protected from

erosion (Balan and Rao, 1996). Apart from utilization of

palm-mat geotextiles or structurally similar materials on

highway slopes, river banks or pond slopes, these could be

used in agriculture as partial cover for certain high risk

crops (such as potatoes) in some pockets of land with high

erosion risk, for protecting high value crops (such as sugar

beet) and to cover bare soil once the main crop is harvested.

As the functional longevity of Borassus and Lala mats is

�2 years, they can possibly be reused in two to three

different seasons and upon degradation the mats would

probably improve soil quality. Cerdan et al. (2006) reported

that mean soil erosion rate of maize plots in Europe is

�13.95 Mg ha�1 y�1. However, mean annual soil loss from

the plots (on a 25 degrees slope) under a 3-year rotation of

Brussels sprouts, potatoes, cabbage, broad beans and

carrots was estimated at �4.3 Mg ha�1 on a sandy soil in

the UK with a mean annual precipitation of 550 mm

(Morgan and Finney, 1982). The estimated mean soil loss

on a maize and soybean field (sandy loam soil) in rotation

in the USA, with a long-term mean annual rainfall of

�900 mm, was �5.3 Mg ha�1 y�1 (O’Neal et al., 2005). In

the experimental year 2007–2008, with similar total

rainfall at Hilton, buffer zone plots on bare soil (cover

percentage �4.1–7.6 per cent) showed a soil loss of �0.4–

1.6 Mg ha�1 y�1 (Bhattacharyya et al., 2008). The rate of

soil loss in these plots at Hilton would have been less if

crops were grown. Thus, these mats could possibly be used



as buffer zones in cultivated areas with high erosion risk

and could significantly decrease soil loss rates.

Low RRE and SYRE in the plots with Bamboo mats were

mainly due to the very steep slope (70 per cent) of the plots

in Thailand. A low RRE (58 per cent) in the plots with Buriti

mats could be due to the very low SOM content (�0.5 per

cent) of the plots in Brazil. Even though cover percentage

was low on the plots in the UK and China, RRE values were

high, probably due to high SOM content.

At �s0.30 per square metre (�s3000 ha�1), covering

agricultural bare soils completely with imported biological

geotextiles would not be economically viable, even if the

mats could be recycled during �2 years. Complete cover

might well be viable for roadway constructions and

preservation of archaeological sites (Bhattacharyya et al.,

2011). However, using these mats as buffer zones in

vulnerable segments of arable land could be worth it to

protect certain high value crops (Bhattacharyya et al., 2009).

Production of palm mats in Brazil, Gambia and South Africa

would create employment for disadvantaged people, while

the application of these biodegradable products on

engineered slopes and tailing dams or on eroded soils

could aid re-vegetation and reduce water and wind erosion.

However, manufacturing of Lala mats in South Africa is

expensive. When employed on a fulltime basis at the

government-determined minimum salary, the price for one

metre square of Lala mats would amount to �US $5.0,

which is �6–7 times the price of imported jute nets.

However, manufacturing Lala mats could still be beneficial

as Lala mats may provide a cost-effective method of

conserving soil in underdeveloped areas in South Africa,

where farming techniques are scaled to low levels of

disposable income and commercially marketed materials are

usually too expensive. Accordingly, Lala mats have a good

potential for soil conservation, effectively conserving soil on

sloping lands, which may be agricultural land or engineered

slopes, such as road embankments or dam walls. In Vietnam,

local people use biological geotextiles produced from

different local materials (i.e. palm leaves, maize straw and

bamboo). Producing geotextiles is time consuming, but

farmers usually do this work at home in their free-time.

CONCLUSIONS

This work forms one of the pioneering research attempts on

the application of biological geotextiles constructed from

palm leaves and other local organic fibres for the control of

soil erosion and runoff volume on problematic slopes, under

the umbrella of the worldwide BORASSUS Project

(www.borassus-project.net). The effectiveness of biological

geotextiles (constructed from indigenous plant materials)

were investigated in combination with grasses or crops

growing through or between the geotextiles (only UK plots


received regular herbicide spraying) for soil erosion control.

The results of field experimentations indicate that the use of

biological geotextiles on bare soil reduced soil loss by �67–

99 per cent in all locations. Effectiveness of different

biological geotextiles in reducing runoff (by 26–81 per cent)

was also notable at diverse locations. The application of rice

straw (area coverage �50 per cent), maize stalk and bamboo

mats is effective in sub-tropical climates (China, Thailand

and Vietnam) for soil erosion control. Results also suggest

that in China and Hungary, �22 and 38 per cent cover of

biological geotextiles, respectively, were very effective in

reducing soil loss. In China, on a 20 degrees slope, �22 per

cent cover of rice straw mats was as effective in reducing soil

erosion as a complete cover of the same mats. Results from

the runoff experiments (8 January 2007–6 May 2008; total

precipitation¼ 1145.8 mm) in the UK suggest that emplace-

ment of Borassus mats as 1 m protective buffer strips at the

lower end of 10 m long plots of bare soil (area coverage �7.6

per cent) reduced total runoff by �81 per cent and total

interrill soil loss by �93 per cent. The completely covered

Borassus mats plots and the Borassus and Buriti buffer strip

plots had similar impacts in reducing soil loss and total

runoff volume relative to bare plots. Thus, use of biological

geotextiles as buffer zones on bare plots has a good potential

for runoff and soil erosion control and the practice of using

these mats as buffer zones could be a better option under

several pedoclimatic conditions.

ACKNOWLEDGEMENTS

This work is dedicated to the memory of Dr Kathy Davies.

We also gratefully thank all technical and support staff

involved in this Project. All authors acknowledge and thank

the European Commission for the financial support of the

BORASSUS Project (contract number INCO-CT-2005-

510745).

REFERENCES

Balan K, Rao VG. 1996. Durability of coir yarn for use in geomeshes. InProceedings of International Seminar and Technomeet on EnvironmentalGeotechnology With Geosynthetics. ASEG/CBIP Publications: NewDelhi, India.

Bhattacharyya R, Davies K, Fullen MA, Booth CA. 2008. Effects of palm-mat geotextiles on soil conservation on loamy sand soils in east Shrop-shire, UK. In: Topic 6. Soil Conservation and Soil Quality, Advances inGeoEcology, The Soils of Tomorrow – Soils Changing in a ChangingWorld. Dazzi C, Costantini E (eds). Advances in GeoEcology 39: 527–539.

Bhattacharyya R, Fullen MA, Davies K, Booth CA. 2009. Utilizing palmleaf geotextile mats to conserve loamy sand soil in the United Kingdom.Agriculture, Ecosystem & Environment 130: 50–58.

Bhattacharyya R, Fullen MA, Davies K, Booth CA. 2010a. Use of palm-matgeotextiles for rainsplash erosion control. Geomorphology 119: 52–61.

Bhattacharyya R, Smets T, Fullen MA, Poesen J, Booth CA. 2010b.Effectiveness of geotextiles in reducing runoff and soil loss – A synthesis.Catena 81: 184–195.



Bhattacharyya R, Fullen MA, Booth CA. 2011. Using palm-mat geotextileson an arable soil for water erosion control in the UK. Earth SurfaceProcesses and Landforms. DOI: 10.1002/esp.2123.

Cerdan O, Poesen J, Govers G, Saby N, Bissonnais YL, Gobin A, Vacca A,Quinton J, Auerswald K, Klik A, Kwaad FFPM, Roxo MJ. 2006. Sheetand rill erosion. In Soil Erosion in Europe, Boardman J, Poesen J (eds).John Wiley & Sons: Chichester; 501–513.

Daniels RB, Gilliam JW. 1989. Sediment and chemical load reduction bygrass and riparian filters. Soil Science Society of America Journal 60:246–251.

Davies K, Fullen MA, Booth CA. 2006. A pilot project on the potentialcontribution of palm-mat geotextiles to soil conservation. Earth SurfaceProcesses and Landforms 31: 561–569.

Dillaha TA, Reneau RB, Mostaghimi S, Lee D. 1989. Vegetative filter stripsfor agricultural non point source pollution control. Transactions of theAmerican Society of Agricultural Engineers 32: 513–519.

Janeau JL, Bricquet JP, Planchon O, Valentin C. 2003. Soil crusting andinfiltration on steep slopes in northern Thailand. European Journal of SoilScience 54: 1–11.

John MWM. 1987. Geotextiles. Blackie and Son: Glasgow.Jones RL. 1993. Role of field studies in assessing environmental behaviour

of herbicides. Brighton Crop Protection Conference Weeds 9B-1: 1275–1282.

Kertesz A, Szalai Z, Jakab G, Toth A, Szabo SZ, Jankauskas B, Guerra A,Panomtaranichagul M, Chau-Thu D, Yi Z. this issue. Biological geo-textiles as a tool for soil moisture conservation. Land Degradation &Development.

Kugan R, Sarsby R. this issue. In-soil biodegradation of palm mat geo-textiles. Land Degradation & Development.

Langford RL, Coleman MJ. 1996. Biodegradable erosion control blanketsprove effective on Iowa wildlife refuge. In International Erosion ControlAssociation, Proceedings of Conference XXVII, Seattle, WA; 13–20.

Leonard J, Richard G. 2004. Estimation of runoff critical shear stress for soilerosion from soil shear strength. Catena 57: 233–249.

Maggette WL, Brinsfield RB, Palmer RE, Wood JD. 1989. Nutrient andsediment removal by vegetated filter strips. Transactions of the AmericanSociety of Agricultural Engineers 32: 663–667.

Mitchell DJ, Barton AP, Fullen MA, Hocking TJ, Wu Bo Z, Zheng Y. 2003.Field studies of the effects of jute geotextiles on runoff and erosion inShropshire, UK. Soil Use and Management 19: 182–184.

Morgan RPC, Finney HJ. 1982. Stability of agricultural ecosystems:Validation of a simple model for soil erosion assessment. InternationalInstitute for Applied Systems Analysis, Collaborative Paper No. CP-82-76.

Munoz-Carpena R, Parsons JE, Gilliam JW. 1999. Modeling hydrology andsediment transport in vegetative filter strips. Journal of Hydrology 214:111–129.

Ogbobe O, Essien KS, Adebayo A. 1998. A study of biodegradablegeotextiles used for erosion control. Geosynthetic International 5:545–553.


O’Neal MR, Nearing MA, Vining RC, Southworth J, Pfeifer RA. 2005.Climate change impacts on soil erosion in Midwest United States withchanges in crop management. Catena 61: 165–184.

Panomtaranchagul M, Sukkasem C, Peukrai S, Fullen MA, Hocking TJ,Mitchell DJ. 2001. Comparative evaluation of cultural practices toconserve soil and water on highland slopes in northern Thailand. In:Multidisciplinary Approaches to Soil Conservation Strategies, HelmingK (ed.). ZALF (Zentrum fur Agrarlanschafts und Landnutzungs-forschung e.V.): Muncheburg, Germany; 147–152.

Panomtaranichagul M, Fullen MA. 2003. Soil and water conservation undercontour cultural practices on sloping land in Thailand. In Proceedings ofthe International Symposium of 25 years of Assessment of Erosion,Gabriels D, Cornelis W (eds). Ghent, Belgium; 525–531.

Pillai MS. 1994. Protection of the side slopes of Kabini Canal. In Proceed-ing of the 5th International Conference on Geotextiles, Geomembranesand Related Products, Rao GV, Balan K (eds). Singapore, 5–9 Septem-ber; 14–17.

Poesen J. 1984. The influence of slope angle on infiltration rate andHortonian overland flow. Zeitschrift fur Geomorphologie, SupplementBand 49: 117–131.

Rickson RJ. 2006. Controlling sediment at source: An evaluation of erosioncontrol geotextiles.Earth Surface Processes and Landforms 31: 550–560.

Rickson RJ, Vella P. 1992. Experiments on the role of natural and syntheticgeotextiles for the control of soil erosion. In Proceedings of CongressGeosintetico per le Costruzioni in Terra -II Controllo Dell’erosione,Bologna.

Smets T, Poesen J, Fullen MA, Booth CA. 2007. Effectiveness of palm andsimulated geotextiles in reducing run-off and inter-rill erosion on mediumand steep slopes. Soil Use and Management 23: 306–316.

Sutherland RA. 1998a. Rolled erosion control systems for hillslope surfaceprotection: A critical review, synthesis and analysis of available data. I.Background and formative years. Land Degradation & Development 9:465–486.

Sutherland RA. 1998b. Rolled erosion control systems for hillslope surfaceprotection: A critical review, synthesis and analysis of available data. II.The post-1990 period. Land Degradation & Development 9: 487–511.

Sutherland RA, Ziegler AD. 1996. Geotextile effectiveness in reducinginterill runoff and sediment flux. In International Erosion ControlAssociation Proceedings of Conference XXVI, 1995, Atlanta, USA;359–370.

Sutherland RA, Ziegler AD. 2007. Effectiveness of coir-based rollederosion control systems in reducing sediment transport from hillslopes.Applied Geography 27: 150–164.

Thompson AM. 2001. Shear stress partitioning for vegetation and erosioncontrol blankets. Ph.D. Dissertation, Department of Biosystems andAgricultural Engineering, University of Minnesota, St. Paul, MN(UMI Number: 3032015).

Vishnudas S, Savenije HHG, van der Zaag P, Anil KR, Balan K. 2006. Theprotective and attractive covering of a vegetated embankment using coirgeotextiles. Hydrology for Earth System Sciences 10: 565–574.


effectiveness of biological geotextiles for soil and water conservation in different...

Documents