The Greenville times. [volume] (Greenville, Miss.) 1868-1917, 1907-06-29


were the common sizes for lateral
drains; but in more recent years
there IS a growingt endency to use
a larger drain. In many sections Of
the country finch tile are the mini
mum size used.
The character Of the soil ii the
sas and the heavy rainfall which Of
ten visits this region will perhaps re
Guire 4-inch tile as minimum; d
: or 6-inch and even an S-inch would
not be too large in some soils.
Depths Of Drains
!. Many Of the best engineers say
that tile should not be lad less than
; feet deep: others advocate mini
mam of feet 4 drain feet deep
h, III drain effectually p per cent.
wider area than drain 3 feet deep.
The extra cost in laying tile at a
depth Of feet will be more than off
set in the larger area drained and il
w;ll, therefore, require less labor and
tile 10 put in the deeper tile
Capacity OF Drains
All the rainfall does not pass di-
rectly into the drains A portion is
cvap0rated at the surface. portion
rams directly into the streams, and
portion is absorbed by the ground
The soil must be thoroughly satur-
acd before any water enters the
drains. With the same temperature
and the same pressure it may be said
shat the coarser the sand and the
smaller the amount OF clay, the more
rapid is the movement Of water
~ {. i ~
movement is slower near the surface
than at a depth OF 10 feet. Likewise
the rate of percolation is more rapid
in summer than in winter 1t is quite
probable that about one-third of the
ground in Mississippi is returned to-
the surface as moisture by capillary
attraction and bv roots of vegetables.
With an annual rainfall Of 40 inches
about 10000 gallons of water to the
acre enters the soil Of the Yazoo Del
Ia. Much OF this water often falls with
in a period Of three months so that in
determining the size Of tile and dis
lance Of drains for under draining it
must have a capacity to remove the
excess OF wafer which falls in so
short a period of time.
Tt has been estimated that a finch
tile drain. smooth inside, and evenly
jointed. and having fall of one foot
in hundred, will dispose of one-half
inch of rainfall III a day Where the
tile drains are laid at a depth OF 81
to 4 feet the soil above this acts as
large sponge to receive the rainfall
and deliver it to the drains
There IS greater danger in laying
tile too shallow rather than too deep.
The old method Of putting in tile
I and feet deep IS rapidly being re-
placed by the more sensible method
of deeper drainage Three and one
haf. and ~ feet are not too deep
to lay the tile drains in ordinary clay
loan soils such AZ we have in the
lower Mississippi Valley
Width of Drains
The width between the drains de-
ponds upon the nature of the soil
and the depth Of the drains. A very
compact clay needs more drains than
open soils But even the stiffest
"buckshot' or gumbo clays may be
made mellow and dry in two or three
years by drains laid 3 or 4 feet deep
and 80 or 40 feet apart.
In the glacial soils Of Iowa good
results nave been obtained by laying
the drains 100 feet apart where they
are 81 to 4 feet deep and 100 feet
apart for drains 3 feet deep
Cost of Drainage
In some sections OF the Tazoo Del
ia there IS a substratum Of sand be-
low the surface OF puckshot clay.
Where the sand is not too far below
the surface it serves the purpose of
tile draining except in the draws and
low flats. Tn having subsiol Of sand.
only the draws and low hats nved lie
The cost Of draining every square
rod will depend on the kind of labor
and the first cost of thing In some
states the cost will run as high as So
or SI4 an acre. But the increase in
the amount Of crops will pay for the
drainage in a few years and the land
becomes better each year