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The water cycle begins when moisture evaporates from the land and
the oceans and heads into the atmosphere. This warm moist air rises
and cools, joining up with dust particles to form clouds. These
clouds are rounded up and herded around by the prevailing winds.
When the clouds are full and the water is too heavy to be suspended
in the air that water heads back to the earth as rain, snow, sleet
or hail.
This moisture can take one of several trails. It can
evaporate before it ever hits the ground or thirsty plants can take
it up. It can be corralled in solid form as glaciers or as
snow-pack. It can take liquid form in lakes, dugouts or swampy
areas. It can mosey or stampede over the land into creeks, streams
or rivers. Or, it can infiltrate into the ground.
Most of the moisture held up by trees or taken up by plants, and
some of that corralled, will evaporate back into the atmosphere. The
water that has penetrated the ground can be stored in the soil or
percolate down through the soil until it reaches the water table
where it becomes groundwater. That which has been stored in the soil
is taken up by plants and then returned to the atmosphere through
the plant leaves.
The ground water may be just below the surface or it may move at
great depths underground in aquifers. Eventually much of the deep
groundwater flows to shallower levels in valleys and in down slope
areas. There it can be used by plants and transpired back into the
atmosphere. It can also discharge into springs, lakes or streams
from which it may evaporate or join the stream flow into
larger bodies of water. Some water makes it to the ocean where
evaporation again continues to drive the water cycle.
As of this writing, there’s no sure fire way I know of that will
change the amount of rain or snow that falls. We can however, have a
say in how effective moisture will be.
When you’re in the middle of a dry spell, every drop counts. Whether
you’re hoping the grass gets a good start in the spring, looking for
some re-growth later in the season or wanting water levels to
recharge above or below ground, getting the most out of the
available moisture is the key. For many of us, an inch of timely
rain can be the difference between “make or break.”
When the snow melts or the rain comes, we need to be prepared, cause
who knows when it will show up again?
And we’ve all had those years
that once it gets started, you don’t know if its ever going to stop!
I’m told that the water we use has been around for hundreds of
millions of years and the amount available has probably not changed
that much – except of course where humans have gotten into big time
tinkering. But for the greater part, water moves around the earth,
changes forms, is taken in by plants and animals, but never really
disappears – just travels along in one continuous cycle.
Many processes are at work to bring us the water we need and these
processes are always at work although I’ve been through some years
that I really questioned that. A good rancher friend once suggested
that maybe the reason we went to the metric system was so we could
get a measure on the miniscule amount of rainfall we’d had one real
dry year. He figured the rainfall could no longer be measured in
parts of inches let alone inches – we had no choice but to go to
millimeters.
Common sense tells us a few good management practices make all the
difference in getting the best use of moisture. Keeping the ground
covered with growing plants or litter is probably the biggest one
above ground, and increasing soil organic matter the most important
below ground. According to my cowboy arithmetic, 100 pounds of dry
soil (that’s roughly a patch measuring 1¢x 3¢ and 6² deep) with an
organic matter level of 1.5% to 2% can hold 35-45 pounds of water,
equal to ½ inch to 1½ inches of rain. On the other hand, soil with
an organic matter level of 4% to 5% can hold 165-195 pounds of
water, equal to 4 inches to 6 inches of rain.
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