Page 101 - Soil Degradation, Conservation and Remediation

88 3 Soil Erosion by Water

Fig. 3.11 Soybean
mulched with corn straw
(Photo courtesy of
USDA-NRCS)

3.4.4 Mulching

A cover spread or laid over the surface to protect soil is called a mulch. Organic

mulches are efficient soil conservation measures (Fig. 3.11 ). Organic mulches
include compost, composted manure, grass clippings, newspaper, straw, and shred-
ded leaves. They are natural and cheap, and along with protection, they improve soil
fertility. Mulching has multiple advantages. It reduces the impact of solar radiation
and raindrops. It protects soil aggregates from detachment by raindrops. It reduces

evaporation and loss of soil moisture; it increases infiltration and reduces amount
and velocity of runoff. It decreases surface sealing, crusting, and compaction.
Stubble mulching is frequently recommended for reducing runoff and erosion.
Residues of wheat or stalk of corn of the previous crop are retained during tilling the
land for next crop without turning them under. Stubble mulch is a very effi cient
protector of wind erosion. Organic mulches release polysaccharides, polyuronides,
and other cementing agents which improve soil structure. Mulched plants have
more roots than plants that are not mulched.

Inorganic mulches also provide many benefits to the landscape. Materials that
can be used as inorganic mulches are crushed gravel and granite, river rock or small