Water Conservation Techniques
The following list of management practices is approximately in
order of
decreasing importance:
•Use good fallow practices with dryland farming. A twofold increase
of
available water has been noted with summer plowing in comparison
with
later plowing.
•Conservation practices. Conservation tillage and PTO terraces
are two
practices that tend to temporarily store or detain runoff, thereby
increasing infiltration.
•Water harvesting. The purpose of water harvesting is to increase
runoff
toward reservoirs or, on a micro-scale, toward plants. It can
be
accomplished by increasing row widths, ridging on the contour,
paving
portions of a watershed, land shaping, and by the selection of
vegetation with low water use requirements.
•Mulching. May reduce evapotranspiration by a factor of 2 over
bare soil
conditions.
•Chemical inhibitors. The chemicals used form a mono-molecular
layer
over either reservoir surfaces or plant leaves.
•Weather modification. Questionable results for immediate crop
benefit;
may increase snowmelt for later irrigation usage.
Irrigation requires huge quantities of high-quality water. Techniques
that reduce water demands include:
•Reduce over-irrigation; it causes excessive return flow and deep
seepage losses.
•Reduce conveyance losses in surface systems. Usually caused primarily
by seepage losses and use of water by phreatophytes; often exceeds
50%
of total water conveyed.
•Reduce evaporation losses in sprinkler systems. Schedule applications
during periods of reduced wind and high humidity, i.e., at night.
Using
drip systems instead of sprinklers, where applicable, also reduces
evaporative losses.