Drought Stress

Monday, June 26, 2023

Do what you can to prepare for the inevitable.

By Colleen Halpenny

Prairie producers continue to look for strategies to prepare for the unpredictable weather patterns that can and will impact crop yields.

While many producers still deal with the ongoing effects of recent droughts (Agriculture and Agri-Food Canada statistics indicated a 40 per cent drop in 2021 crop yields across the Prairies), we spoke with some industry experts on mitigating drought-related damage.

Starting strong

Trevor Herzog, Western Canada agronomy lead with Corteva Agriscience, knows the biggest variable farmers are challenged with is preparing for the potential of drought or high-heat scenarios.

"We can't predict weather patterns, or what the summer will look like, but if we can do our best to establish the crops well, in preparation for potential dry spells, we are setting the stand up with the best possible advantages."

Herzog suggests increasing plant stand populations, as the canopy closing in a faster and denser fashion will increase the soil moisture profile prior to the onset of dry conditions.

"If we can get the ground covered in a healthy and vigorous crop, the sun can't beat down through the vegetation and dry the soil out, so we're protecting as much spring moisture as we can to extend through the growing season."

Herzog says that for good crop establishment, we need to step back and look at our planting procedures.

He advises producers to ensure drills are set to consistent depths for each field's individual profile, to capture even emergence and optimal placement into the seedbed's moisture.

"We always need to consider our fertility program, and how it may need to be adjusted based on the weather conditions we are experiencing and what the long-range forecast looks like.

"If we think the spring looks dry, and it appears as though we may have a dry or droughty and hot summer season, we would explore reducing initial fertilizer rates at seeding time, and instead have a backup plan to top-dress later in the spring as moisture starts to come. This will allow us to have an increased opportunity to advance the yields on a cost-conscious basis."

Picking the right variety

Herzog points out that earlier maturing canola hybrids are being advanced that may assist farmers in mitigating the negative effects of drought.

By allowing the plant to have extra flowering time prior to high-heat days, there is a higher chance to optimize yield potential of the crop, especially with canola.

"Under drought or heat stress canola will drop later emerging flowers, especially at the top of the canopy and on side branches. The plant begins to shift energy towards filling established pods rather than continuing to support new pod development. We see significant yield loss when this occurs," he says.

As weather and moisture challenges continue across the Prairies, Herzog shares that Corteva and their breeding program are working on hybrids to address these realities.

Breeding high-heat and drought-resistance can be more challenging than insect and pest resistance, but Herzog says the team is working to bring as much innovation to Prairie crops as possible to assist producers in meeting their yield goals.

He reminds producers to be cautious with spring moisture, as the risk of spring frost with early seeding dates can be detrimental.

Herzog suggests producers explore additional crop types which are beneficial to their operation and suitable for their historical precipitation.

"Crops like corn, especially if you have livestock, are a great option for taking advantage of what may be a dry or droughty season. The plant can use moisture available in a more efficient way than some of our other traditional canola and pulses can."

Adaptation

"Prairie producers are some of the most adaptive farmers in the world. They have persevered through some of the most challenging weather conditions, and they keep farming!" says Dr. Dave Sauchyn, director of Prairie Adaptation Research Collaborative and professor of Geography and Environmental Studies at the University of Regina.

Sauchyn points out that global warming will lead to both excess water and also drought, at extreme levels, based on climate modelling.

The warming effect is expected to also occur during winter months, leaving producers' fields more susceptible to pathogens and insects which in the past were killed off by a colder climate.

"The Prairies are unlike anywhere else in the world. These producers farm in high latitudes, in large acres, in the centre of a continent. The weather patterns they are exposed to are volatile because of the distance any storms need to travel from the ocean to reach them, and it's what has kept them so innovative," he says.

Sauchyn also notes a belief that producers have become increasingly adaptable due to the annual cycle of production. He explains that winter breaks have allowed farmers to connect with other producers, learn from industry meetings, research into adaptive practices, and find new varieties to grow.

"When you reflect on the 1980s, the Prairies had a large volume of soil erosion from droughts, and so producers largely adapted fallow fields and minimized tillage to protect their soil. And in today's community, we see that minimum tillage, no-till, and cover crops are standard practices. So something they've decided was positive for reducing erosion is now proactively working to adapt to potentials of low precipitation by storing as much moisture as possible in the seedbed."

Reflecting on the recent Western Canada Conference on Soil Health & Grazing held in Edmonton, Sauchyn says he was shocked at the attendance for a regenerative ag presentation.

"It's a fairly new term being used, and a wide range of management practices fall under it. The main focus is preventing loss of water from the soil, and improving soil health to maintain and hold water, to protect against the impacts of climate change."

Sauchyn says that in the past a presentation on regenerative agriculture might be viewed as "radical" but he reports that things have shifted quite quickly.

"This discussion had over 500 attendees in the room, and more waiting outside the doors. Producers have indicated that they want to learn, and are taking this very seriously."

For Herzog, it's all about overall health.

"A crop that is healthy and which started strong is much more capable of withstanding challenges that may appear in July and August from drought or heat stress. If farmers employ available resources towards a strong and healthy plant stand, they've done what they can to be successful against something they have little control over: drought." BF