ust a few columns back, we lamented the shortage of farmland for young farmers wanting to expand. Now we find that poor farm land can be reclaimed by drainage.
Conditions might not allow it elsewhere, but parts of the west side of California’s San Joaquin Valley respond to soil drainage like a dog to a bone. Large areas of land degraded by saline-sodic soils become arable when drain tiles are installed, even if irrigation water still contains some salt.
Tiling to allow drainage of tainted irrigation water is not a new concept, and it is a standard practice in many areas of fertile soil throughout California. But the area of a study undertaken by the U. S. Department of Agriculture Agricultural Research Service (USDA ARS) was practically a wasteland before the drainage was installed.
In the current issue of Agricultural Research, published every other month by USDA ARS, some dramatic photos show how completely degraded the expanse was before tiling. It was ugly marshland supporting only the barest of low-growing grass among crunchy salty deposits. Even weeds struggled to exist there.
But photos of the same land after drain tiles were buried well beneath the surface showed robust irrigated livestock forage thriving as it replaced the former crusty surface.
And after a year or more without irrigation, it appeared to be returning to its original scrubby condition.
Many westside farmers learned long ago to provide some kind of drainage to help clear their crop land of naturally occurring boron and molybdenum as well as salt. Most of them have directed the drained water to collection ponds where it is allowed to evaporate, leaving a heavy salty residue.
But the ARS team headed by soil scientist Dennis Corwin managed to pump the water from some drainage ponds and use it to irrigate the desolate marshes thought to be incapable of sustaining positive crop life. His team applied the saline irrigation water to an 80-acre plot of what they called the worst case example of the degraded area.
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They determined that the irrigations, even with saline water, leached salts and trace elements below the root zones of plants, leading to “a significant and rapid improvement in soil quality.” And they noted an overall decrease in the soil’s sodium absorption ration. From 1999 to 2004, salinity decreased 21 percent.
Of course, the benefits of draining those westside soils is not news to longtime growers in the area. They participated in tiling and sending the salty collections to the Kesterson Reservoir years ago as recommended by government sponsored research at the time.
But the high boron content of the drain water as it collected in Kesterson turned out to be the death knell for several types of wildlife, most notably the peregrine falcon.
Environmentalists had fits, and the feds determined that the only remedy was to plug the drains.
Until the environmental disaster, Kesterson Reservoir was viewed as the solution to the government’s failure to make good on its earlier promise to provide drainage, probably to the Pacific Ocean, of the tainted westside soils. Growers and others are still wary of government promises, some transferring to the feds’ handling of water issues of any kind.
“We’re from the government and we’re here to help you,” is the satirical ending to many anecdotes shared in the farm community. The recent drainage accomplishments brought about by Corwin and his team have helped remove the salt, boron and that other stuff from the soil, but some sarcasm from the fed relationship as well.
Don Curlee operates his own public relations firm specializing in agriculture issues. His column appears in The Sentinel every Thursday. Email Don at firstname.lastname@example.org.