Farm Progress is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Ag runoff sampling reveals surprises

No one in agriculture has been surprised pesticides have been detected in sloughs, creeks and rivers of the San Joaquin Valley since water sampling began a little more than two years ago.

What is somewhat surprising is how few hits have been recorded.

What is surprising and potentially explosive are the high levels of e. coli found at the 19 monitored as part of the Westside San Joaquin River Watershed Coalition.

This is a coalition of water and irrigation districts covering 450,000 acres of farmland stretching from Mendota, Calif., in the south to Tracy, Calif., in the north. It is one of several coalitions formed statewide to monitor and mitigate possible ag water pollution.

The findings from two years of testing were detailed at a meeting recently at Locke Ranch in Mendota, Calif., where management practices were outlined to keep farm inputs out of farm drainage and irrigation runoff.

As onerous and unwelcome as this water testing has been on agriculture, it has also been revealing. Agriculture is not as bad an actor as some environmental activists thought.

Agriculture representatives are frankly, surprised at how few hits have been found. However, Parry Klassen, executive director of Coalition for Urban/Rural Environmental Stewardship (CURES), does not expect fewer pesticide finds to deter the environmental activists.

This was the reason behind the work of CURES and others in developing best management practices (BMP) that would mitigate any pesticides getting into waterways.

BMPs such as:

  • Lower pesticide rates
  • Proper mixing and loading of pesticide sprayers
  • Proper equipment calibration
  • Adopting new spraying technology
  • Creating buffer zones around sensitive areas
  • Grassed drainage waterways
  • Vegetative filter strips
  • Drainage management

It is all about being proactive in dealing with the most onerous environmental regulations in the most productive agriculture state in the nation, said Roger Isom, vice president of California Cotton Ginners and Growers Associations.

“It is all about finding solutions that save money and address environmental solutions,” he said.

The Locke family of Mendota, Calif., has spent 75 years creating solutions to stay in business on a 1,500-acre farm bordered by some of the most important waterways in the state, the San Joaquin River, the Delta-Mendota Canal and the Mendota Pool which also takes water from the Kings River.

It is like farming under an aquatic microscope, but there are significant benefits to farming adjacent to a river, according to Gary Martin, a family partner in the Locke Ranch.

“There are a lot of good bugs around that river and that helps us spray less than maybe farmers on the West Side of the San Joaquin Valley,” he said.

The Locke farm is 1,500 acres irrigated mostly by surface and well water. Crops include cotton, alfalfa and new almond orchards irrigated with micro sprinklers.

Row crops are flood irrigated with a variety of systems to collect and discharge irrigation tailwater either directly into the river or to evaporation ponds or to a canal drainage district.

Martin says the farm tries to re-circulate as much tailwater as practical to irrigate crops again with the same water.

The farm has been practicing minimum tillage for more than a decade to reduce soil movement off fields, leaving cotton beds in place for as long as five seasons before they need to be knocked down and the field cleaned up.

They use poultry manure on the beds. That, combined with decomposing crop residue, builds up organic matter. Soils are monitored for residual nutrients to reduce primarily, nitrogen inputs.

The Locke family also is involved in a sustainable cotton project where beneficial insects are released and harbored in in-field habitat.

“We try to do as much of our spraying as we can with ground rigs. We use hooded and banded sprayers; shut off nozzles when we turn at the end of a row,” Martin said.

“We do a lot of things other people do as well to protect the environment.”

“We are motivated by practical approaches that are responsible and make good economic sense. The Locke family has been here for 75 years, and we are here to stay,” Martin said.

Chris Linneman, assistant program manager for the 450,000-acre Westside San Joaquin River Watershed Coalition, said significant toxic pesticide levels have been measured 44 times at the 19 monitoring sites since July 2004. Some 13 of those times the levels were high enough to warrant testing for the specific pesticide.

All of this testing under the eyes of the Central Valley Water Control Board could lead to more regulations.

“The bottom line is that if we can keep pesticides out of the water it will save everybody a lot of money,” he said.

To that end, Klassen and Linneman indicated it may be relatively easy. Both believe fields closest to the waterways most likely are the source of the pesticides in the water.

“There are six million acres of farmland in the Central Valley and the regulators think everyone is discharging water into waterways,” says Klassen, who is also a small farmer.

“My neighbor would have my head if I drained my orchard into one of his fields.” He disputes regulators' contention.

Rather, he believes high-risk farming properties adjacent to waterways — a half-mile to a quarter-mile away — can be identified and mitigation measures can be put in to place to reduce pesticide and sediment runoff.

Klassen believes pesticide detection in water can be reduced and, “We can show the regulators and the public we are responsible.”

The pesticide issue, however, may become insignificant compared to the e. coli problem facing regulators as a result of testing.

Very high levels of e. coli have been detected during the past two years at all the coalition's test sites, said Klassen, “and that may take decades to deal with.”

Linneman noted that the water he is testing is not drinking water, but untreated rivers, streams, sloughs and creeks.

This finding is sure to pose a dilemma for regulators. Linneman hinted that at least some of this must be coming from wildlife. It could be human waste; it could be runoff from manure used for organic farming; it could be coming from livestock or dairy operations.

Linneman said DNA testing is now underway to determine the sources of e.coli.

“We can deal with the components involving irrigated agriculture,” said Klassen, adding it may take decades to deal with the total e.coli problem.

“I am not sure what we can do about it if we wanted to,” he said. For now it is on the back burner.

“It is not being ignored, but the focus is on pesticides right now,” he added.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.