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close this bookResource Management for Upland Areas in Southeast Asia - An Information Kit (IIRR, 1995, 207 p.)
close this folder3. Soil and water conservation approaches
View the documentIntroduction to soil and water conservation approaches
View the documentBench terraces
View the documentComposting
View the documentContour tillage/planting
View the documentCover crops
View the documentCrop rotation
View the documentDiversion ditches
View the documentDrop structures
View the documentGrass strips
View the documentHedgerows
View the documentMinimum tilIage/zero tillage
View the documentMulching
View the documentRidge terraces
View the documentShifting cultivation
View the documentSoil barriers
View the documentSoil traps
View the documentWater harvesting

Grass strips

Planting grasses along contour lines creates barriers to minimize soil erosion and runoff. It induces a process of natural terracing on slopes as soil collects behind the grass barrier, even in the first year.

Grass can be planted along the bottom-and sides of ditches to stabilize them and to prevent erosion of the upper slope. Grasses can also be planted on the risers of bench terraces to prevent erosion and maintain the stability of the benches.

Grasses are trimmed regularly (every 2-4 months) to prevent them from flowering, shading and spreading to the cropped area between the strips. Thus, grass strips can be very appropriate for farmers who cut and carry fodder for their animals. Grasses can also be used as mulch for crops.

On hillsides, grass seeds or tillers are planted in double rows (50 cm apart) along the contour with varying distances between the double rows. In ditches, tillers are planted close together in rows. On the risers of bench terraces, they are planted in a triangular pattern at a spacing of 30 cm x 20 cm.

Examples of grass species commonly used are: setaria (Sitaria anceps), ruzi grass (Brachiaria ruziiensis), napier or elephant grass (Pennisetum purpureum), guinea grass (Panicum maximum), NB21 (Napier crossed with pearl millet), lemon grass (Cymbopogon citratus) and vetiver (Vetiveria zizanoides).

Advantages

Controls soil erosion and runoff.
Provides fodder.
Grass can be used as mulch.

Limitations

Labor is required for management of grass strips.
Ruzi grass can root itself from cuttings.
Mulching of grass cuttings may contribute to the weed problem.
Uses land which may otherwise be used for food production.

Factors affecting adoption

Biophysical

Not applicable on steep slopes or areas with longduration rainfall.
In dry areas, grasses cannot withstand drought.

Socioeconomic

Farmers may not have time to manage intensively, resulting in weed problems.

In traditional farming systems where livestock graze freely, farmers may not wish to use cutand-carry practices.

Farmers feel that grasses serve as a refuge for rodents which threaten food crops.

Planting materials are not available in many upland locations.

If farmers do not own livestock, they have little incentive to plant grasses.