Page 103 - Soil Degradation, Conservation and Remediation

90 3 Soil Erosion by Water

Fig. 3.13 Strip cropping (Photo courtesy of USDA-NRCS)

3.4.6 Strip Cropping

In strip cropping, two or more crops are grown in alternate strips (Fig. 3.13 ). Crops
of different strips vary in their root/shoot characteristics and cultural requirements.
Crop strips break sloping landscapes in wide segments with diverse vegetative cover

which intercepts runoff and promotes water infiltration, thereby reducing runoff and
soil erosion. Sod-forming crops may be alternated with cereals, legumes with non-
legumes, and root crops with vegetables. Strip cropping gives yields as good as
monocropping. The width of the strips depends on soil slope, erosion potential, crop
type, and equipment size. Narrow strips reduce flow lengths more effectively than

wide strips. The width of strips must match the equipment turn or width for cultiva-
tion. On gentle slopes of up to 5 %, a strip width of about 30 m is recommended
while on steeper slopes the width must be less than 20 m (Bravo and Silenzi 2002 ).
Strip cropping may be successfully combined with contour farming.

3.4.7 Contour Strip Cropping

Contour strip cropping is planting row crops in strips on the contour (Fig. 3.14 ). It

is more efficient in erosion control than contour farming and strip cropping alone
because of the plant and crop diversity. The grass, legumes, or small grains used in
strips slow runoff and trap sediments leaving row crops. Permanent grass/legume