Features Structures & Equipment Water and irrigation
Inside View: August 2012

Greenhouse Canada features often focus on the importance of accurately monitoring water quality

Greenhouse Canada features often focus on the importance of accurately monitoring water quality, managing EC and pH and crop nutrition, along with other water-related topics such as irrigation techniques, drainage and water treatment methods.

There’s ample information and advice available about many aspects of water use. For example, the “Water Education Alliance for Horticulture,” led by Dr. Paul Fisher and hosted by the University of Florida, helps growers conserve water and manage water quality issues.₁

However, a bigger question that comes up increasingly often now is simply: where can we source sufficient water from?

In Canada, a total of 1.9 million acres of land was irrigated in 2010, 8.9 per cent less than in 2005.₂ However, the “decrease in total area irrigated across Canada was largely attributed to the above-average precipitation in several regions of the country in 2010,” reports Statistics Canada.

Alberta reported “the largest area of land irrigated in the country with 65.2 per cent of the [Canadian] total, most of which was irrigated field crops and irrigated hay and pasture. British Columbia reported the second largest area of land irrigated with 14.4 per cent of the national total. British Columbia continued to report the largest area of irrigated fruit crops in Canada, with the fruit area irrigated increasing 21.₃ per cent in this province to a total of 48,077 acres. This offset the decrease in fruit irrigation in some other provinces, such as Ontario, resulting in a national increase of 5.2 per cent.”

This is going to change. Significantly. The World Economic Forum’s “Water Resources Group” (WRG) warns that global water demand will exceed supply by over 40 per cent by 2030.3 This is reported in a recent newsletter from Lloyd’s. (Yes, the insurance company.)
There’s more. “The world’s air has reached what scientists call a troubling new milestone for carbon dioxide, the main global warming pollutant. Monitoring stations across the Arctic this spring are measuring more than 400 parts per million of the heat-trapping gas in the atmosphere.”₄

So what? Well, according to the UK Irrigation Association, “climate change threatens to reduce the reliability of water supplies for horticultural production.”5 “In today’s farming environment, horticultural production is all about ‘adding value’. But everything hinges on a secure access to water, which can no longer be taken for granted,” says Mark Hall of the UK’s Hall Hunter Partnership, fruit growers.₅

“In 2001, the CO2 concentration in the [U.K.] atmosphere was about 370 ppm. The UKCIP predictions suggest that this figure could double, depending on the scenario.” …  “The [CO2] changes will impact on crop physiology and could be a potentially significant driver of irrigation demand. Higher CO2 concentrations will increase the potential yield of many crops – due to improvements in the carbon partitioning within the plants. The increased plant growth in root crops, for example, results in an increase in the storage organs, e.g., the main sugar beet taproot and potato tubers, increasing the yield. Where this is the case, crops could be harvested earlier for the same yield – thus reducing water requirements, or at normal harvest time to take advantage of the higher yield. Yield increases could, however, result in less land being planted to grow the same volume of produce, reducing water use.”₅

BE PROACTIVE, NOT REACTIVE; THE WAY WE GROW WILL CHANGE
■ Plan for (at least) two things:
Make do with less. “It may seem more likely that this year’s Chelsea Flower Show [in London] will be a washout than a drought, but water shortage remains one of the big themes at this year’s event. After record rainfall across the U.K. last month, it is hard to believe that the annual gardening show … will be affected by a hosepipe ban. But exhibitors at this year’s event have had to respond to drought conditions and hosepipe bans affecting large parts of England. As a result, some of Chelsea’s top horticulturalists are heeding warnings of future water scarcity in their garden designs.”3 Don’t think that can happen here in Canada? Well ….
Make sure Canadian water is used to grow Canadian crops. Do some homework and check out what’s happening to the water that you think is “ours.” It might surprise you.

1. http://www.watereducationalliance.org
2. Stats Canada 2011 Agriculture Census. http://www.statcan.gc.ca/pub/95-640-x/2012002/05-eng.htm
3. “Water shortage inspiring drought-proof horticulture,” Lloyd’s Newsletter, Tuesday, 22 May, 2012.
4. Associated Press, guardian.co.uk, Friday 1 June, 2012
5. UK Irrign Assn, http://www.ukia.org/eabooklets/EA_Climate%20Change%20Impacts%20Horticulture_Final.pdf

Gary Jones is chair of Production Horticulture at Kwantlen University, Langley, B.C. He serves on several industry committees and would welcome comments at Gary.Jones@Kwantlen.ca.