This is just one post in the Conservation Category

“Efficient” drip irrigation may deplete more water

Posted by: Aqua Blog Maven on November 26, 2008 at 6:40 am

From the Worldwatch Institute:

An Israeli water engineer was sitting under a tree one day when he noticed a leaking faucet slowly drip water to the tree’s roots, a nearly 50-year-old irrigation tale says.

The idea inspired the invention of modern drip irrigation, also known as micro-irrigation. The method runs water through plastic tubes that release the flow through small holes directly to crop roots or stems.

The precise application allows drip-irrigated crops to be watered more frequently than with traditional sprinkler methods. Yet farmers waste fewer resources because most water is absorbed through transpiration. As a result, many governments have encouraged drip irrigation as a water-conserving technology that can boost crop yields.

But drip irrigation may have a downside, according to a study published in last week’s Proceedings of the National Academies of Science. In traditional flood or sprinkler irrigation, “wasted” water - the water not absorbed by crops - seeps into the ground and recharges the below-surface aquifers used by area farmers. As drip irrigation becomes more common, recharge of groundwater may be less frequent, the study said.

“I think it’s very true that drip irrigation and drip irrigation subsidies definitely contribute to food security and increased farm income,” said Frank Ward, the study’s co-author and a professor of water resource economics at New Mexico State University. “The only downside…is that drip irrigation could be using more water.”