[Water_news] 1. DWR'S CALIFORNIA WATER NEWS - Top Item for 11/21/2008

Department of Water Resources

California Water News

A daily compilation for DWR personnel of significant news articles and comment

 

November 21, 2008

 

1.   Top Items -

 

Drip Irrigation May Not Save Water, Analysis Finds

The New York Times

 

Water quality advances in danger
Farmer sees conflict between food safety and conservation
The Capital Ag Press

 

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Drip Irrigation May Not Save Water, Analysis Finds

The New York Times – 11/17/2008

By Henry Fountain

 

In an effort to make irrigation more efficient — to obtain more “crop per drop” — farmers have adopted alternatives to flooding and other conventional methods. Among these is drip irrigation, shown above, in which water flows only to the roots. Drip systems are costly, but they save much water.

 

Skip to next paragraph Or do they? A hydrologic and economic analysis of the Upper Rio Grande basin in the Southwest, published in The Proceedings of the National Academy of Sciences, suggests that subsidies and other policies that encourage conservation methods like drip irrigation can actually increase water consumption.

 

“The take-home message is that you’d better take a pretty careful look at drip irrigation before you spend a bunch of money on subsidizing it,” said Frank A. Ward, a resource economist at New Mexico State University and author of the study with Manuel Pulido-Velázquez of the Polytechnic University of Valencia in Spain.

 

With flood irrigation, much of the water is not used by the plants and seeps back to the source, an aquifer or a river. Drip irrigation draws less water, but almost all of it is taken up by the plants, so very little is returned. “Those aquifers are not going to get recharged,” Dr. Ward said.

 

Drip irrigation also generally increases crop yields, which encourages farmers to expand acreage and request the right to take even more water, thus depleting even more of it. “The indirect effect is very possibly to undermine policy attempts to reduce water consumption,” Dr. Ward said.

 

Policymakers, he added, must balance the need for more food and for farmers to make a living with water needs. “It’s fair to say that subsidies are very good for food security and very good for farmer income,” Dr. Ward said. “But they may be taking water away from other people.”#

 

Water quality advances in danger
Farmer sees conflict between food safety and conservation
The Capital Ag Press – 11/21/2008

By Cecilia Parsons – Staff Writer

MONTEREY - Farmers now have more to balance than their checkbooks. Profit margins aside - it's safety margins that can spell out a good harvest or doom it for waste.

To ensure their crops meet safety standards, some are questioning and even abandoning conservation practices.

According to speakers at the fourth annual Sustainable Ag Expo, strides made in water quality improvements on farms in recent years are in danger of being lost due to food safety concerns.

Since the 2006 E. coli outbreak in spinach that was traced to a San Benito County farm, growers of leafy-green vegetables have come under increased pressure to remove all possible sources of pathogens from their fields.

Conservation practices such as vegetative filter strips, hedgerows and ponding basins, promoted to growers as improving water quality, have been questioned. The practices prevent run-off of sediment, nutrients and pesticides from fields, but buyers of leafy greens and third-party auditors charged with ensuring food safety are asking growers to curtail those practices because they believe them to a source of pathogens that can cause food-borne illness.

"There is the perception of risks to food safety, but there is no good data to back it up," said Trevor Suslow, a University of California researcher.

Rather than see growers abandon conservation practices and wipe away all non-cultivated plants from their fields and surrounding areas, fence out or trap wildlife, Suslow and others are continuing research into causes of leafy-green vegetable contamination and whether conservation practices do contribute to pathogen loads.

"It's a balancing act for farmers," said Danny Marquis of Natural Resources Conservation Service.

They want to protect water quality, but they are told to discourage wildlife, he said. A grower survey conducted by the agency found that many had been told by auditors to remove vegetative strips next to fields.

Marquis pointed out some of the positive effects of conservation practices - along with some drawbacks. Hedgerows, planted along vegetable fields, can intercept dust and pests and even prevent spray drift. But, they can also provide cover for rodents.

Windbreaks can reduce soil erosion and improve irrigation efficiency, but they can also harbor birds and other wildlife.

"We need to weigh the pros and cons, and mitigate the risks," Marquis said.

Joe Pezzini, of Ocean Mist Farms in Castroville and chairman of the Leafy Green Marketing Agreement, said growers are really stuck between buyers who want all possible sources of contamination removed and water quality regulations.

The Leafy Green Marketing Agreement, formed after the 2006 E. coli outbreak, has production standards that can be measured and verified. The agreement does not preclude all conservation practices, but there are buyers who are asking for more stringent production methods.

There is a question at that point, Pezzini sail, if it is science or a selling point for produce.

"Legislators and consumers want more food safety and there are environmental concerns," Pezzini said. "Growers are stuck in the middle."

Kay Mercer, who works with growers as executive director of the Central Coast Agricultural Water Quality Coalition, affirmed that food safety concerns were limiting adoption and implementation of some conservation practices.

A survey of 600 growers in Monterey County in 2007 showed that 90 percent had adopted at least one conservation practice on their farming operations, with most planting cover crops and building irrigation reservoirs or tail water recovery ponds.

However, those practices had an impact on their bottom line.

Deer tracks in a field cost them $17,000 in crop losses. One romaine lettuce crop was rejected because it was deemed to be too close to a horse pen. Crops were also rejected because of contact with Salinas River water or because they were too close to frog or tadpole habitat.

Mercer said processors' response to the crop losses or rejection was to remove or eliminate wildlife. Overall, 21 percent of leafy green growers have adopted at least one measure to do that, she said.

To resolve the conflict, Mercer said University of California researchers are looking at what happens to pathogens that are caught in management practices, where they come from and where they go during all phases of crop production. They are also identifying animals that are significant pathogen carriers.

Research is aimed at finding management practices that preserve food safety while improving water quality.#

 

 

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