<br />THE EXf'EFllmEnTI!IL SITE
<br />
<br />Research results at the U.S. Salinity Laboratory, Riverside, California, indicate that with
<br />frequent irrigation, crops can tolerate higher salinity at the bottom of the root zone than
<br />previously assumed permissible, without significantly reducing crop yield. Using frequent
<br />irrigation concentrates the salt into a smaller volume of water, causing some of the salt to
<br />
<br />precipitate. It therefore becomes immobilized in solid form deep in the soil profile. As a
<br />consequence, the amount of salt in the return flow should be reduced as well as the
<br />volume of drainage water. Reducing the volume of drainage should reduce flushing of the
<br />saline aquifer and consequently dissolve less salt from the underlying shale.
<br />
<br />Buried Irrilltion Pl.eline
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<br />Weilhing
<br />Lysimeter
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<br />Salinity sensor
<br />site. One each
<br />at.5, 1 &2
<br />loot depths.
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<br />The experimental sitrJ is located below the
<br />
<br />Highline Canal northeast of Fruita, Colorado.
<br />
<br />Evapotranspiration (E T) plus leaching
<br />
<br />percen tages 0, 5. and 15 represen t the
<br />
<br />applications to the pie-shaped sections under the
<br />
<br />center-pivot sprinkler sysmm to attain the
<br />
<br />desired leaching percentages. The surface
<br />
<br />irrigation system to the ~st (left) is treated
<br />
<br />at leaching percentages of 10 and 20.
<br />
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<br />PlotS6
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<br />Plot 55
<br />ET+ 5$...
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<br />100 200
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<br />Plot 52
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<br />
<br />----R'oadW-;'y----
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<br />o
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<br />"1!Kilcales amount 01 irription wallapplied in excess of crop evapotranspiration (ET) requirements.
<br />
<br />Scale of Feet
<br />
<br />1~6Z00
<br />
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