LONGER GROWING SEASON — BUT ALSO MORE PESTS
Farmers in the Fraser Valley will be able to grow crops virtually yearround under a warming climate. At lower elevations, 45 days will be added to the growing season by the 2050s and 56 days by the 2080s, the climate-change report for Metro Vancouver predicts.
Farmers may seize the opportunity to plant more valuable crops and can expect earlier harvests.
But those benefits will be countered by increased pests and plant diseases. And variations in temperature and precipitation may cause pollinators to emerge at the wrong time.
Brent Harris is a fifth-generation Delta farmer who grows mixed crops — potatoes, beans, peas, corn and grain. He likes the idea of a longer growing season “although we might all be under the ocean by then.” But he believes that farmers will have to adapt to more extreme weather events year-round.
Last year he planted his corn in late April — the earliest date ever, by 10 to 14 days — because of the warm weather and dry fields.
On the other hand, the pond on his property was frozen for skating for a full month this winter — something that has never happened before. He also recalls 2010 when his potato crop was ruined by wet weather.
“We don’t want to get lulled into complacency, and start assuming you’ll be able to plant and harvest on certain days,” said Harris.
Ted van der Gulik, a former senior engineer in the Ministry of Agriculture who is president of Partnership for Water Sustainability in B.C., notes that the longer growing season and hotter weather will increase the need for irrigation.
There is potential for irrigated farming to increase from 15,000 hectares to 35,000 in Metro Vancouver, he said, but new infrastructure will have to be built.
The regional government currently supplies water to less than 470 hectares — most greenhouses on a metered system.
That leaves farmers to use their own wells or surface water sources, including from the Fraser River pumped from ditches.
“Irrigation systems will have to become more efficient and also managed properly to make sure water taken and applied is beneficial and not wasted,” he said.
Reduced flows on the Fraser combined with rising ocean levels will allow salt to expand its reach upriver to Pattullo Bridge by 2050, he added.
“Water will have to be drawn between tide cycles and there is no guarantee that sufficient water will be available.”
It’s also important that rainwater is allowed to replenish aquifers during winter rains, he continued, noting that urban development works against that.
“The water runs off the roadways, rooftops and parking lots and enters the surface waterways and makes its way out to the ocean. This water is lost and cannot be used in summer months when we need the freshwater resources.”