LETHBRIDGE -Century-old research plots are giving scientists valuable information about how farming has affected soil on the once virgin prairies.
Elwin Smith, research scientist at the Agriculture Canada Lethbridge research centre, said data from such ongoing studies is needed to analyze the past and provide information for the future.
“Changes in the soil are generally slow so you need long-term data to get information about how cropping practices impact the soil,” he said.
The centre has maintained extensive records dating back to the initial cultivation of Palliser’s Triangle that turned it from grassland to irrigated and dryland acres today.
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“It’s quite an accomplishment to keep them up so long,” said Smith.
“There were some questions they never knew about when they put it in,” he said of fields that have been in wheat since before the First World War.
The plots were planted to help show incoming farmers what the southwestern corner of Alberta was capable of growing.
These early experiments, now among the oldest ongoing studies of their kind in Canada, have explored crop rotation, fertilizer rates, tillage, simulated erosion and revegetation with grasses. They have provided information for research into sustainable cropping systems, nutrient cycling and global change.
Smith said these plots will become part of research in the future on topics not yet imagined.
Wading into thigh-deep crops, scientist Ben Ellert and his crew of technicians measure greenhouse gas emissions in a field of irrigated wheat.
These fields were originally broken with horse and plow and flood irrigated until the 1970s, he noted.
When they were first planted, no one knew about greenhouse gas emissions and climate change or how the management of land affects the broader environment.
“We can predict how the environment will change in those situations,” Ellert said, adding that these plots rotated with alfalfa, potatoes, sugar beets, wheat and oats, have maintained good productivity over the years.
“What we’ve learned is you can sustain organic matter with judicious management of cropping systems and appropriate crop rotation and an integrated manure integration system,” said Ellert.
In the future, the researchers will help answer questions about how a switch to low protein wheat for the emerging biofuel boom could affect farmland.
Researcher Henry Janzen said the centre is the steward of a unique and phenomenal resource.
“We’ve documented the transition taking place in the land from the inception of agriculture to the present,” he said. “When you know the past trajectory, you can better envision how the future will unfold.”
Janzen showed off glass jars of soil and leather-bound log books dating back decades and read the reports of early scientists listing their use of 3.5 pounds of twine and a six-inch plowing depth.
Initially, the goal was to learn how to make these lands productive and enable farmers to thrive, he said. That focus has shifted to how well the land is doing and what practices allow the land to be productive for future generations.
Recent work on carbon dynamics in these systems is helping scientists build models to show how land can pull carbon dioxide out of the atmosphere and store it in the soil.
These long-term sites are especially valuable because soil carbon changes over many decades, Janzen said.
“We need the patience and persistence of the long-term sites to really document changes.
“We need these lands as listening places, places where we go to see how the land is doing from human-induced and other changes,” he said.
“Unless you have these sites in place, where you know what happened over history, then how do you know change when it happens?”
