Carbon dioxide (CO2) in the atmosphere and organic matter (carbon) in our soils are topics of great current interest. Two big questions that take up much ink these days are: 1) how can we emit less CO2 with farming practices and 2) how can we sequester more carbon (C) in our soils to maintain high yields?
We spend the most time researching annual crop rotations, but perennial grass has received much less attention. This piece will summarize a detailed study with smooth bromegrass on a Thin Black Loam soil near Crossfield, Alta., which is about 20 miles north of Calgary.
The experiment was conducted by the then Westco Fertilizers led by John Harapiak. It carried on for 27 years, so it is not a one-year wonder.
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PAg and CCA types who want to see the original data can find it with Google by searching, “Influence of long-term N fertilization on quantity and quality of organic C stored in a grassland soil.”
Tables 1 and 2 below show the increase in soil C and CO2 mass after 27 years of fertilization of bromegrass with nitrogen (N). For CO2, the actual mass rather than concentration of C is used. The mass data takes into account the differences in soil bulk density.
The amount of carbon sequestered in the soil is significant and continues to contribute as long as the stand is maintained. At the same time, annual hay yields increased by four tonnes per hectare or more with 112 kilograms of nitrogen per hectare.
However, the Crossfield area of Alberta is special.
The foothills hay country
The foothills hay country along Alberta Highway 547, west of Crossfield, we used many times to avoid Calgary traffic on the way to a summer rest at Radium Hot Springs. It was clearly “hay country.” Haybines could barely cut it. In the odd pasture situation, cows were up to their bellies in grass.
The area is at a high elevation (3,900 feet), and with 17 inches annual precipitation it is ready-made to grow grass and sequester carbon to soil, especially with a good nitrogen fertility program.
Cattle and carbon: Why beat up on the cowboys?
So, why all the fuss about cattle and methane release. A highly grass-productive area like Crossfield is productive because it supports cows — and perhaps a few chuckwagon and racehorses.
In the Brown and Dark Brown soil areas of Saskatchewan and Alberta, we cannot expect the kind of grass growth and carbon sequestration that occurs in the Alberta foothills.
However, in the drier areas, the cow-calf operation utilizes land not suited to annual grain production. Feed problems and market conditions of recent years have reduced the North American cow herd to frightening levels. There was a buzz about plant-based “pretend beef” but that has fizzled out quickly. For my money, I will take the real thing, thank you!
So what if cows eject a bit of methane out both ends. What in the name of common sense do climate alarmists think the 60-million-plus buffalo did when they roamed freely on the open Plains up until the late 1800s?
If readers want more info on buffalo hunting, they can try to snag a copy of The Last Buffalo Hunter by Norbert Welsh as told to Mary Weekes. Norbert Welsh was 80 years old and blind when Mary Weekes interviewed him and wrote the book.
Norbert was a tough old bird. He was a Red River Metis who led buffalo hunting excursions to various areas, including the Dundurn area where my farm is located. He would come in the fall and “build a house” (that is, a poplar log shack) and spend the winter. He was there at the time of the 1885 unrest but kept clear of it.
I stumbled upon the book at the University of Saskatchewan library, while looking for something else, and read it. Later, I ordered a paperback version from Amazon to have a copy at home — but that is now missing? In the meantime, the Amazon price has gone too high so I will keep looking for my copy.
I hope you all get a holiday somewhere warm to break up our frigid Prairie winter.
