Hi-Line Farm & Ranch November 2017: Heat and drought could be new normal, experts say
November 1, 2017
The dry and hot 2017 weather, compounded by fires in some areas, has been rough on north-central Montana’s agriculture producers.
The Havre-north-central region received 3.18 inches of precipitation from March to September, the National Weather Service reports. The region saw 14.83 inches of precipitation during that same period in 2016.
This year has been like nothing he has ever seen in his nearly 30 years at FSA, Executive Director of the Hill County FSA Office Les Rispens said.
“It was a strange weather year. I don’t know that I’ve seen such a combination,” Rispens said, referring to the drought and fire-plagued year.
Unlike in 2016, when winter wheat low yield was caused by the destructive wheat streak mosaic virus, this year’s low yields were the result of drought. Spring crops — spring wheat, lentils, barley, chickpeas — yields were below average because of the lack of rainfall.
“It wasn’t a great crop. It was just a crop,” Rispens said.
Livestock production, too, was hit hard. Some ranchers, Rispens said, ran out of water as ponds and other water sources ran dry. Thanks to drought and the East Fork Fire, ranchers were left with a lot to desire in the way of grazing. The good news, Rispens said, was that only 20 cattle were lost in the fire, a low number given how large the fire was and how many cattle were moved around to avoid it.
Some relief did arrive for ranchers when grazing was authorized beginning July 16 on CRP acres. Forty-two Hill County livestock producers took advantage of that, Rispens said.
The silver lining to this year’s late moisture — which started with three days of rain in mid-September and peaked with record-setting snow at the beginning of October — is the good it’ll do next year, Northern Agricultural Research Center Superintendent Darrin Boss said.
“If it can be absorbed into the soil instead of running off, it’s going to be recharged because plants and things like that are going into a dormant period, so they have that ability to make that moisture available for next year,” Boss said.
The late season precipitation, more hot summer days and drought — as there was this year — is projected to be the “new normal,” according to agroecologist Bruce Maxwell.
Maxwell is the co-director of the Institute of Ecosystem at Montana State University and a contributor to the extensive “2017 Montana Climate Assessment.”
Annual average temperatures — including daily minimums, maximums and averages — have risen by 2 to 3 degrees Fahrenheit across Montana between 1950 and 2015, the “Montana Climate Assessment” says.
“By mid-century, Montana temperatures are projected to increase by approximately 4.5 to 6 degrees depending on the emission scenario. By the end-of-century, Montana temperatures are projected to increase 5.6 to 9.8 degrees depending on the emission scenario,” the assessment says, adding the state-level changes are larger than the average changes projected globally and nationally.
The winter precipitation average has decreased by .9 inches, largely attributed to an increase in El Niño events, especially in the western and central parts of the state. A 1.3- to 2-inch increase in spring precipitation also occurred during this period for the eastern part of the state.
Moisture is projected to increase in winter, spring and fall and decrease in summer across the state. The largest increases are expected to happen during spring in the southern part of the state. The largest decreases are expected to happen during summer in the central and southern parts of the state.
The projected change in climate will affect Montana’s water resources and agricultural sector.
Rising temperatures will reduce snowpack, shift historical patterns of streamflow and likely put more stress on Montana’s water supply during summer and early fall.
Montana’s snowpack has declined since the 1930s in mountains west and east of the Continental Divide. The decline has been most prominent since the 1980s, the report says. Warming temperatures over the next century, especially during spring, are likely to reduce snowpack at mid and low elevations.
Earlier onset of snowmelt and spring runoff will reduce late-summer water availability in snowmelt-dominated watersheds. Groundwater demand will likely increase as elevated temperatures and changing seasonal availability of traditional surface-water sources — dry stock water ponds or inability of canal systems to deliver water in a timely manner — will force water users to look for other sources
Rising temperatures will worsen drought periods, the assessment says.
Rising temperatures will likely intensify droughts when and where they happen. Changes in snowpack and runoff timing will likely increase the frequency and duration of drought during late summer and early fall.
Montana’s agricultural industry generated more than $5.2 billion in 2014 through the sale of agricultural commodities. Agriculture will feel the impact of the changing climate. The assessment, however, reports that gauging the effect climate change will have on agriculture faces “multiple layers of uncertainty,” including uncertainty that accompanies all climate projections, is specific to agricultural projections and is created by human interventions that can mask a direct climate impact signal.
Decreasing mountain snowpack will continue to lead to decreased streamflow and less reliable irrigation during the late growing season. Reduced irrigation capacity will have the greatest impact on hay, sugarbeet, malt barley, market garden and potato production. Higher temperatures will allow winter annual weeds, such as cheat grass, to increase in winter wheat cropland and rangeland. This will cause lower crop yields and forage productivity as well as more wildfires.
Farmers will adapt to the climate change with diversified cropping systems, including rotation with pulse crops and innovations in tillage and cover-cropping. Projected temperature and precipitation increases may benefit some ag producers in the short-term, “but the effects of warming will become increasingly disruptive as they accelerate beyond adaptation thresholds,” the assessment says.
More frost-free days and longer growing seasons will potentially allow for greater crop diversity. But more 90-plus-degree days will increase evaporation and water demand for most crops, limit grain development from pollination to seed and raise heat stress on livestock. Projected increases in winter temperature and spring precipitation are likely to increase current crop diseases and pests. For example, increased planting of winter wheat will be accompanied by increased crop pests, such as wheat stem sawfly, and the natural regulation of this pest by native parasites will likely decline.