SEEPAGE IRRIGATION
 By J. M. Myers

 Pasture Program 3 involved the use of seepage irrigation as
a cultural practice. Approximately 33 acres of pasture was in-
cluded in the program with one-half of it being subject to irriga-
tion. The other half of the pasture in the program was treated
the same as Pasture Program 1.
 The physical components of the seepage irrigation system
consisted of a deep well water source, a turbine pumping unit,
main ditch with water level control structure, and "V" shaped
lateral ditches spaced 135 feet apart. The lateral ditches had flat
side slopes and were about 18 inches deep. Pasture plants grew
within the bounds of the ditches as well as they did on the land
between the ditches. Nine shallow wells, about three feet deep,
were randomly located in the pasture to facilitate measuring
depths to the water table.
 Management of seepage irrigation was based on depth to the
water table during various parts of the growing season. When
clover was the primary plant species on the pasture, the irriga-
tion pump was started when the water table receded to an aver-
age depth of 24 inches below the soil surface. Pumping would
continue until the water table was raised to an average level of
18 inches below the soil surface. When grass was the primary
pasture plant, the water table was allowed to recede to 30 inches
before pumping was started and was continued until the water
table was raised to 18 inches below the surface. During average
dry periods, about three days of pumping were required to raise
the water table from 30 inches to 18 inches below the surface,
and in three to five days it would recede back to 30 inches.
 For the seven-year duration of the experiment, an average
of approximately 23 inches of irrigation water was required per
year to maintain the desired water table levels.

 Results
 Details of production responses and the economic evaluation
of the program are presented in other sections of this bulletin.
Pasture Program 3 produced annually about 40 pounds of beef
per acre more than Program 1, which was treated similarly ex-
cept for irrigation and the addition of 200 pounds per acre of
0-10-20 fertilizer on the irrigated area. These results do not re-
flect typical responses to seepage irrigation. The properties of