Worms and water

Kemper, W.D. and Trout, T.J. and Segeren, Antone and Bullock, Murray (1987) Worms and water. Journal of Soil and Water Conservation. 42(6):401-404.

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Abstract

A raindrop's value to a farmer depends
upon whether that raindrop is available
or not available to the farmer's
crop. Rates at which cloud bursts deliver
water often exceed the rates at which water
can move into the root zones of crops
through the tiny pores between soil particles.
Small puddles of water then develop on the
surface. These puddles may grow until
water flows over the lowest banks, joining
overflow from millions of other puddles to
flood nearby creeks. Meanwhile, much of
the crop root zone remains dry.

In adjacent fields with macropores, puddles
may also start to form, but the accumulating
water drains into the soil
through the macropores fast enough to prevent
the puddle from overtopping its banks.
Once the storm is over, the field with
macropores will often have far more water
in its root zone.

Macropores are bigger than the little
pores that exist between closely packed soil
particles. Large pores between clods, old
root channels, and cracks due to drying and
soil shrinkage are all macropores, but Bill
Edwards at the Agricultural Research Service
research station in Coshocton, Ohio,
says that earthworm holes are the most effective
macropores for draining puddles on
the test watersheds at Coshocton. Edwards
has a field that has been in untilled corn for
22 years. He has measured rainfall and
runoff on this and nearby fields of tilled corn
throughout this period. According to Edwards,
rainfall has averaged 39.4 inches per
year, while runoff averaged 4.9 inches on the
tilled plots and 0.08 inch on the untilled
plots.

Edwards and colleague L. D. Norton
counted an average of about 6 large worm
holes per square yard on the tilled plots and
155 holes per square yard on the untilled
plots (5).

Farmers can't do much about the amount
of rain they will get, but Edward's findings
indicate that farmers can work with worms
to capture precipitation in the root zones of
their crops.

Item Type:	Article
NWISRL Publication Number:	0644
Subjects:	Practical farm efficiency Irrigation > Sprinkler irrigation Irrigation > Furrow irrigation
Depositing User:	Dan Stieneke
Date Deposited:	10 Apr 2008 16:48
Last Modified:	06 Jan 2017 21:41
Item ID:	492
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/492