Help protect your crops from weather extremes

Monday, November 23, 2020

By Kate Ayers
Staff Writer
Better Farming

As increasingly extreme weather adds another element of unpredictability to crop production, farmers are considering changes in their operations to help maintain yields.

"Studies show that we can definitely expect more volatile weather," Rebecca Shortt said in an interview with Better Farming.

"In Ontario, the models show that we should expect more precipitation but the increase in temperature will outstrip the increase in precipitation. So, the crop's demand for water will increase at a faster rate than precipitation will increase."

Shortt is the water quantity engineer at the Ontario Ministry of Agriculture, Food, and Rural Affairs and is based in Simcoe. She has extensive experience working with horticultural producers who have irrigation systems in their operations.

As a result of the variable weather patterns, her research team expects more drought-related crop stress in the future.

"Plants require between 500 millimetres (20 inches) and 600 mm (24 in.) of water to produce grain crops" in the province, Shortt said.

"Studies project a 25 per cent increase in corn heat units. Based on this analysis, we would see that crop water needs could" increase to 550 to 640 mm (22 to 25 in.), which is "50 mm (2 in.) more than current needs. The frequency and intensity of rainfall is hard to predict, though," she said.

Farmers could use irrigation to mitigate yield losses from drought.

"Field crop producers have expressed increased interest in irrigation systems, particularly following the drought of 2012," Shortt said.

But growers must take some important factors into consideration before installing irrigation systems for field crop production.

"Producers should evaluate (a) the risk that they face, so in this case, the drought potential and (b) the price of the crop," she said.

"Corn is the grain crop where we expect to see the biggest impact from drought and potentially the biggest benefit from irrigation."

Drought conditions will have a greater effect on corn yields than soybean yields, she added.

"When the corn price is high, that often drives producers to maximize their yields," she said.

Some potential barriers to the adoption of irrigation in cash crop operations include water availability, water regulations, and cost.

"If a farmer has a water source available on their property," this situation addresses one barrier. "If not, that is another hurdle that they must overcome," Shortt said.

In addition, "to take water for commercial agricultural purposes, a farmer must have a Permit to Take Water from the Ministry of the Environment, Conservation and Parks."

These permits are required "for anyone taking over 50,000 litres (11,000 gallons) in any one day of the year. This volume equates to applying approximately one inch (25.4 mm) of water on half an acre. Farmers would exceed this limit and would be required to undergo that regulatory process," she said.

In addition to the capital costs of investing in irrigation infrastructure, farmers must also consider operational costs, such as power and labour.

"Depending on the type of irrigation system that a farmer purchases, there are costs to operate the equipment," Shortt says.

Grain farmers would need to "consider increased labour demands during the growing season."

While irrigation could help farmers maintain productivity, many factors play into the feasibility of this infrastructure. Producers should consult experts in this area during planning and installation. BF