ONTARIO, Ore.—Growers along the Oregon-Idaho border who depend on water from the Owyhee Reservoir to irrigate their crops have had to change the way they farm.
They have no choice. The annual water allotment for the 1,800 farms that depend on the reservoir has been slashed by about two-thirds during the past three years as a drought grips the region.
The reservoir provides water for 118,000 irrigated acres in Malheur County in Southeastern Oregon and around Homedale and Marsing in Southwestern Idaho.
This was the fourth straight year of reduced snowpack runoff in the Owyhee Basin, which feeds the Owyhee River and the reservoir. The Owyhee Irrigation District receives water from the reservoir and delivers it to irrigators through 400 miles of canals, laterals and ditches.
“I know growers who are growing onions on 1.7 to 1.8 acre-feet of water. Ten years ago that never happened; we used almost twice that number to grow an onion,” Ontario, Ore., farmer Bill Johnson said. “So clearly this drought has forced us to change our practices.”
‘All of the above’
To get by, farmers have switched irrigation practices, left ground fallow, grown crops that require less water and mature earlier, changed rotations—anything that will get them through until the snow and rain return to normal.
“It’s kind of been all of the above,” said Stuart Reitz, an Oregon State University cropping systems extension agent in Malheur County. “Growers are doing what they have to do to make a crop.”
OSU cropping systems extension agent Bill Buhrig said farmers are trying many ways to make the water they do have last.
“It’s like a combination (lock),” he said. “Growers are trying to turn it and unlock next year’s success.”
Nyssa, Ore., farmer Paul Skeen said a lot of farmers have switched from a 24-hour watering set to a 12-hour set and sometimes even six-hour sets. A set refers to how often water is moved across a field.
“You’re getting across the field in half the time, so you’re ... using less water on that field, which gives you more for other fields,” he said.
Farmers are leaving a lot more ground fallow, which allows them to use what water they have for the area’s cash crops, such as onions and potatoes. They’re growing more crops that require less water such as like peas, beans, seed crops and grains.
But there’s a catch to switching to low-water crops.
“They try to rotate crops that take a lot less water ... but those crops provide less income, too,” said Owyhee Irrigation District Manager Jay Chamberlin. “That’s completely thrown their rotations out. It’s going to take years to get back into their rotation.”
The drought has resulted in more farmers switching to irrigation pivots, Buhrig said.
“One grower I talked to said, ‘My reduced water allotment goes a lot further through sprinklers than it does through furrow irrigation,’” Buhrig said. “He said, ‘After two years of being reactive, I feel like I need to get on the offense a little bit here.’”
Farmers have also switched a lot of acres to drip irrigation systems.
Skeen switched about 40 percent of his onion crop to a drip system this year and “that’s probably going to be up around 60-65 percent this coming year,” he said. “I’m just trying to save water and have a better crop.”
‘Get me over’ crops
Some farmers are turning to crops such as triticale or camelina that need little or no irrigation water, Buhrig said.
Those crops won’t provide much income but at least they help a farmer cover some of the fixed costs associated with his land, he said.
“They’re not high-dollar crops but they’re ‘get me over’ crops,” Buhrig said. “Leaving a field fallow is not cheap. Your water bill and taxes stay the same.”
Weeds become a major issue in fields left fallow, Chamberlin said.
Weed patches have developed on some land left idle “and now they’re going to have to fight that weed seed for the next several years,” he said.
Because sugarbeets and corn for grain are both high-water crops and need water longer in the season than many other crops, acreage for both is down by about a half compared to normal in the region, Buhrig said. More shorter-season corn varieties were planted, he added.
Onions are a high-water crop, but they are also the main cash crop in the area, so those acres have decreased only slightly during the drought.
Farmers are getting more conservative with their fall fertilizer programs, Buhrig said.
“It’s getting a little harder to spend that $300 on fertilizer in a fall-bedded operation if you don’t know for sure you’re going to (have the water to) be able to grow that crop the next year,” he said.
Water from the irrigation district stopped flowing in August the past two seasons—about two months earlier than normal. But because the allotment was reduced by two-thirds, a lot of farmers ran out of water in July.
The effects of the drought have been felt most severely on the 50,000 acres along the upper parts of the irrigation district, where growers are totally dependent on water from the reservoir.
Growers on the lower parts of the system have access to supplemental water from the Snake River, but that also increases their pumping costs.
Shorter rotations
The availability of additional water on the lower parts of the system has created its own problem.
Because growers have switched a large portion of their cash crops, mainly onions, to parts of the system with more water, it has resulted in shortened rotations.
For example, instead of planting onions every four or five years in a field, farmers might plant them two out of three years or three out of four years to take advantage of the water that is available there.
Those types of practices aren’t good over the long term because they can lead to a build-up of soil-borne diseases and poor crop quality, Reitz said.
“If you can’t rotate through to other crops, (the problem) just gets compounded year to year,” he said. “For the long term, we don’t want to see those kinds of practices continue.”
Through the drought, much of the work being done at the OSU research station has centered on helping growers maximize the efficiency of their irrigation.
Drip irrigation
Researchers worked on about 40 experiments this year involving drip irrigation, said Clint Shock, the station’s director.
Some of the work, such as the station’s drip irrigation trials, has been going on for two decades. The station has for years studied irrigation scheduling—turning water on and off at the right time, Shock said.
The drought has caused a lot of growers to adopt those practices, which the station has preached about and studied for years, he said.
Growers and water managers in the area are keeping a close eye on the precipitation forecast for the coming winter. Currently, there’s about a 50-50 chance of the basin receiving a normal amount of snowpack, Chamberlin said.
With only about 5,000 acre-feet of available carryover water stored in the reservoir—far below the 350,000 acre-feet that would be expected during an average year—farmers in this area are heading into 2016 with even more uncertainty regarding their water supply.
“Right now farmers are (preparing) ground for next spring not knowing what kind of water year they are going to have,” Chamberlin said. “That’s tough when you’re looking at a (reservoir) that’s empty.”
Source: www.capitalpress.com