The severe statewide drought could cost California’s agriculture industry $2.2 billion in combined losses and added expenses, and lead to the loss of more than 17,000 jobs, according to the Center for Watershed Sciences at the University of California, Davis.

Jay Lund, the center’s director, said he expects “substantial local and regional economic and employment impacts.”

And another university specialist has a dim view of the future of the state’s agricultural industry.

Farmers have tapped into groundwater as the three dry years have shrunk California’s reservoirs, Lund said.

Meanwhile, additional research has started suggesting more alternatives for the state’s farmers and ranchers, who worry that market prices may not cover their losses, he said.

“This drought is unprecedented,” said Doug Parker, director of the University of California’s Institute for Water Resources and who is in charge of the Strategic Initiative on Water Quality, Quantity and Security.

“We’ve never had such a lack of rainfall since we started keeping track,” he said. “Farmers are looking for ways they can stretch their water budget.”

He said growers have left some of their fields fallow since they can’t irrigate, and ranchers are selling cattle they can’t feed.

But agricultural researchers are looking at recycled wastewater from municipal waste treatment plants as a way to irrigate vineyards, he said.

“California recycles only 7 percent of the 9 million acre-feet of urban wastewater produced per year, and the state wants to nearly quadruple that by 2030,” he said.

Besides providing a source of irrigation water during drought, recycling water is cost-effective and reduces wastewater discharge to rivers, he explained.

To see if recycled water can be used in Napa vineyards, the University of California’s Cooperative Extension researchers evaluated the quality of water treated by the Napa Sanitation District (NSD). They also looked at its impact on soil

They discovered that the quality of the recycled water was similar to that of other local sources of irrigation water, and that in a vineyard that was irrigated with recycled water for eight years, the soil did not accumulate salts or such toxic ions such as boron.

The recycled water was relatively high in nitrogen, but Parker said growers have some options in dealing with that chemical.

In many vineyards, the higher soil nitrogen levels would present no problem to the vineyards. But should growers need to reduce nitrogen, they can plant cover crops, such as cereals and other grasses during the winter.

In northern Salinas Valley, many growers have been using recycled wastewater since 1998 to irrigate their crops.

That sent researchers to another study, because of worries that salt accumulation in the soil could present other challenges.

The latest research data indicate that since 2000, only a small amount of sodium has accumulated in the 12-inch deep rooting zone.

But in half of the fields studied, chloride has accumulated to levels that could affect yields of strawberry plants and leafy greens, such as spinach.

This chloride buildup might be due to the recent lack of winter rainfall, which normally washes salts out of the root zone, and researchers have said this could be mitigated by improving drainage and avoiding soil amendments that contain chloride.

About 20 percent of the total agricultural use of water statewide is for growing alfalfa, which Parker called California’s “thirstiest crop.” In addition, large amounts of irrigation water can be wasted as runoff, he said.

About 70 percent of the California-grown alfalfa is fed to dairy cows. that produce milk, used in a variety of products, including ice cream, cheese, yogurt and butter in addition to the milk itself.

New research by the University of California suggested a mathematical formula could avert that water waste.

If they use the formula to predict the advance of irrigation water across a field, and combine it with wireless sensors that track the water’s advance, alfalfa growers could reduce runoff significantly, down to a trickle, Parker said.

In addition, the new approach would free growers from having to be present in person to check the status of field irrigation, saving both time and labor.

Forages, rice, cotton, almonds and pistachios and deciduous trees also are heavy drinkers.

More than 95 percent of the water taken up by plants is evaporated,through transpiration as well as from evaporation from soil surfaces.

Parker said one way to save water is to grow native plants.

“Most ornamental plants are happy to stay in gardens, but some jump the fence, invading wildlands and crowding out native plants,” he said.

“California has a wealth of native plants, about 3,400 species, but is also plagued by more than 1,500 species of invasive plants, many of which were introduced by the horticultural trade,” he said.

The University of California is studying this as well, and has identified 186 ornamental species that have invaded Mediterranean areas in other parts of the world, and are at high risk of becoming invasive here as well.

He said those studies also are analyzing additional risks of imported ornamentals, and are helping land managers identify invasive species that may show up in wild areas.

California produces more than 250 different crops, is the nations top producer of 75 commodities and is the sole producer of 12 of them, among them almonds to artichokes, olives, pistachios and walnuts.

On the average, California irrigates 9.6 million acres, using 34 million acre-feet of water from surface or groundwater sources.

Blaine Hanson, of UC-Davis’s Department of Land, Air and Water Resources, said 80 percent of the developed water supply is used for agriculture. In dry years, agriculture needs use 52 percent of the total water supply, and in wet years, agriculture consumes 29 percent of the total water supply.

He has noted that agriculture can’t compete economically with urban and industrial sectors for water, because farmers aren’t paid much for their products but need a ;pt of water for each unit of production.

“Regardless of the economics, if we want food, we will have to pay the price in terms of water and land for producing the agricultural products used to produce our food. There is no other choice if we want food,” Hanson said.

He said farmers are looking at gravity irrigation, sprinkler irrigation and microirrigation to determine which method works most efficiently for their respective crops.

Gravity irrigation is less expensive to use, but it might take a trial and error approach before it can be managed correctly and to reduce runoff.

Sprinkler irrigation has a moderate capital cost, and operational expenses are moderate. It can be easy to manage, but its efficiency is limited by wind, Hanson said.

Microirrigation can cost up to $1,000 an acre to set up, but it applies water precisely throughout a field, Hanson said. It can be easy to manage, but there are moderate labor costs and the system’s susceptibility to emitter clogging.

He said researchers are trying to help farmers find more efficient ways to irrigate their fields, but said many researchers aren’t familiar with agricultural irrigation, and tracking where water goes is difficult.

He isn’t optimistic about the future as the state’s various sectors vie for available water..

“It is unlikely that increasing irrigation efficiency will have a large impact in supplying the predicted future water needs of the urban-industrial and environmental sectors,” he said. “Agricultural land will need to be removed from production to supply the needed water.”