Coming Ontario's way: A climate like Kentucky's
Saturday, November 3, 2012
Environment Canada is predicting that, by 2050, it will seem like we have moved 500 to 1,000 kilometres south. That will mean more heat, more bugs and winters no longer cold enough to kill off diseases and pests
by MIKE MULHERN
While 2012 may have been what one entomologist called "the year of the insect," it was also the year when March seemed like May. Both realities may be harbingers of things to come.
If Environment Canada projections are correct, rising temperatures by 2050 will make it seem we have moved 500 to 1,000 kilometres south. Southwestern Ontario's climate will closely match the current climate in the state of Kentucky. Shorter, warmer winters will be coupled with longer growing seasons that will include longer dry periods, especially in July and August.
Moving across the province, forecasters predict that Ottawa's weather might look like today's weather in Columbus, Ohio, and Sudbury might eventually experience Cleveland's weather.
Essex farmer Henry Denotter, 2013 president-elect of the Ontario Soil and Crop Improvement Association, says the last two growing seasons demonstrate that change is evident. "Last year, we went from four feet of rain in the growing season to probably less than two feet in 2012."
Denotter has been no-tilling for about 20 years, and he thinks that's one way to reduce erosion in years when rains are heavy and a way to maintain soil moisture in years when things are drier. For farmers who are trying to get ahead of climate change, he recommends doing an environmental farm plan. "Self-assess your operation," he says, "and try to improve it from there."
But, Denotter warns, the plan only works if it's followed. "You can lie to yourself if you want," he says, recalling conversations with farmers who had used a no-till drill but they always wanted to go out and work the field twice before planting, just to make sure. His method is to minimize passes and "try to do it all in one shot."
Another thing farmers are doing is looking at hybrid performance, especially in corn. In Essex County, the Soil and Crop Improvement Association has six test plots scattered throughout the county. "We get varieties from all the (seed) suppliers and compare them side by side," he says.
Working with the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), they have students who scout the plots for disease and later test for quality and yield. They do the same with soybeans, although in fewer plots.
With warmer temperatures comes a bug migration into Ontario. Tom Cowan, an entomologist working out of OMAFRA's Ridgetown office, is seeing the arrival of new insects such as the marmorated stink bug, and others.
"We've had a couple of sightings (of the marmorated stink bug) in the Hamilton area," Cowan says, "so we've confirmed that there are adults there." He says they are field crop pests, mostly on corn and soybeans, but they are more of a problem for fruit crops.
"They are hitchhikers," Cowan says. "They come on shipments of building materials or on infested plant material shipped in from the United States." They also fly and congregate in winter shelters, including houses. "They get a winter harbour and spread out over the summer."
During the 2012 growing season, Cowan's crop reports noted pressure from stink bugs but also the alfalfa weevil, the true armyworm, the potato leafhopper, spider mites, the variegated cutworm and the thistle caterpillar. Cowan wrote that 2012 may go down as "the year of the insect in field crops."
Climate envelope
The question is whether this is a trend. Jonathan Newman is the director of the school of environmental sciences at the University of Guelph.
"With any given species," Newman says, "we try to figure out their climate envelope – what are all the limitations on a particular species in terms of temperature, humidity, precipitation, soil moisture, those sorts of things." Figuring out where that envelope will be in the future predicts, in part, where the pests will materialize.
For agricultural pests, Newman says, movement doesn't solely depend on climate, but also on the availability of host plants. "The climate area has to be moving to an area where we actually grow that crop." However, even the lack of a traditional host does not protect an area from invading pests.
Some species are generalists which can eat a number of things, Newman says, and some are specialists which are adapted to a particular crop. While swapping hosts is not common, Newman says, it can happen, especially with "severe selection pressure like climate change."
While growers saw a large number of pests in Ontario crops during the 2012 growing season, Jocelyn Smith, research associate and program lead for insect resistance management and field crop pest management at the Ridgetown Campus of the University of Guelph, says there are also signs of increased predator activity, especially the western bean cutworm which has been in Ontario since 2008 and now overwinters.
"We're seeing predators going after the egg masses," Smith says. "We also saw lots of lacewing larvae and ladybugs in the field that were also eating the egg masses and the young larvae, so we're seeing predation by natural enemies, which is a good sign." Smith says that when a pest becomes established, "there's usually something that comes along to control them."
When there is western bean cutworm in a corn field, Smith says, losses can be as high as 15 to 20 bushels per acre in a heavily infested field. The bug is native to North America, originating in the southwestern United States. While it is a corn pest, it also attacks edible or dry bean crops.
Looking ahead at our weather future, Dave Phillips, a climatologist with Environment Canada, says there may be more rainfall yet drier ground, because more intense temperatures will take up moisture. Even the Great Lakes will be lower in the future, possibly by a metre or more by 2050. All the lakes are presently below historical levels. Lake Huron today, Phillips says, is down more than half a metre compared to the historical average over 90 years. But the prospect of the Great Lakes drying up altogether is not in the cards. That would take thousands of years, Phillips says.
Although temperature projections are being made for the long haul, up to the year 2100, Phillips says the science is not yet there to predict with certainty even what the coming winter will bring. We can, however, take a longer view based solely on temperature projections and look ahead to the day when southwestern Ontario might feel more like Kentucky.
"People think bluegrass and all that sounds very inviting," Phillips says, but there are other less appealing factors. "They have five times more hail storms than we have here and, in terms of severe thunderstorms, severe tornadoes, they have more of those per square kilometre than any other state in the union."
Precipitation a major issue
Phillips says a temperature increase of two to three degrees by 2050 will add warmth but will also take away the advantages we have now with winters that are more severe.
"One of the best things about our climate," Phillips says, "is that winters kill a lot of vermin, varmints and diseases. They can't survive. We are the second coldest country in the world and the snowiest country in the world, and that does give us some advantage from insects and creatures that just can't make it during our cold seasons."
Phillips says warmer temperatures will make precipitation a major issue for farmers. "We might get more precipitation, but maybe not enough to match the increased temperatures."
Unfortunately, Phillips says, how climate change will present itself is not predictable. "We used to think that everything would be gradual and we would have a chance to change our ways as the climate changes and, to some degree, that happens. We are talking about two or three degrees of warming by 2050, but perhaps four to five degrees by the end of the century. Imbedded in that gradual kind of change will be some surprises, some wild cards."
One of those wild cards, he says, was last winter, the second warmest and third driest on record. Last March, he says, was outside even what models might have predicted for 2100.
John Cowan, vice-president of the Grain Farmers of Ontario (GFO), says so far farmers are keeping up with changes in the weather.
"The increase in either no-till or zone tillage is significant. It's unbelievable how much our tillage practices have changed," he says, noting that concerns about both soil erosion and soil moisture are part of the reason. "We've learned that recreational tillage on some soils just isn't necessary."
Looking back, Cowan says that in the 1950s and ‘60s "we had a corn borer inspector who would actually go around from farm to farm and if you had too much corn stover on the ground, he would make you replow your ground." Of course, that was before anyone was discussing what everyone is aware of today – climate change.
Chad Lee, a grain crops extension agronomist at the University of Kentucky in Lexington, did some of his graduate work in Michigan, so he knows about climates in both Ontario and Kentucky.
"To start with," Lee says, "we have a much milder winter in Kentucky. We have snow, but it very rarely stays around for more than a day or two." However, frost dates before planting range from April 17 in Lexington to May 10 in Louisville. Annual temperatures range from -23 to plus 40 C. The growing season is 165 to 195 days.
There are some advantages to the Kentucky climate. Farmers there get four reliable forage cuttings a year. And they follow winter wheat (harvested in June or early July) with soybeans that yield just 10 per cent less than soybeans planted as a single-season crop. In years like 2012, some Ontario soybeans go in after wheat but the yields are generally quite low.
Kentucky has deep, lakebed soils and a lot of sloping soils, much of which is no-till. Tobacco is still an important crop in Kentucky, along with corn, wheat, soybeans and forages. Most farmers in Kentucky take a no-till approach to farming to conserve moisture and reduce erosion.
As for weather extremes, Lee says Kentucky can have dry summers. "Somewhere in mid-July, we get pretty hot and dry, so that's an issue for us." He says it sometimes turns dry in July, sometimes in August. "Depending on when that shows up, either the corn or the soybeans are gonna hurt from it."
He says farmers in Kentucky don't have to spray as much as farmers farther south. "We are right on the threshold for that," he says. "In Tennessee, for example, they spray a lot more for bugs. We spray occasionally for stink bugs, but not at their level. They also spray a lot for loopers or inch worms." He says, in Kentucky, they get more stink bug damage in corn than in soybeans.
Projections for climate change in Kentucky, Lee says, show there will be more rainfall in the winter, less rainfall in the summer. "Winters will be milder, but they will be more prone to dramatic swings in temperature."
Weather outliers
When Dave Phillips looks ahead at Ontario's weather, he sees an uncertain forecast. "Generally, when you look at the future," Phillips says, "you see things gradually warming up, but there are these outliers – these surprises that we saw in March – that will give us a glimpse of what will be normal. It was all abuzz this March but, in 2020, it probably wouldn't be."
When people ask Phillips what they should grow, he says he tells them to plan based on the last 10 years of weather, not the last 40 years. "I will often say to a farmer, ‘Don't make your planting decisions based on the (Environment Canada) seasonal outlook. The science is not there yet'."
He does tell them to factor everything in – crop options, weather projections, economics – and make a decision based on current realities. "Don't do what your grandparents did." BF