Northwest Saskatchewan farmer Tim Nerbas knows if he does the best job of managing crop production above ground, it is probably providing the most benefit to all activity going on below ground.
He doesn’t test to measure the amount of organic matter in the soil on his 4,000-acre grain, oilseed and pulse crop operation near Waseca, southeast of Lloydminster. He knows it is variable, but he also knows the production practices applied over the past 25 to 30 years of farming have helped improve soil quality.
“We haven’t done the testing, so my assessment is anecdotal,” says Nerbas. “But I can tell that soil quality has improved. It has improved tilth and texture and improved moisture holding capacity. Last year was extremely dry and I was impressed at just how well crops did grow, simply because the soil was able to retain a bit more moisture, even under dry conditions.”
Read Also
Good news, bad news for fungicides meant to fight stem rot in canola
A report shows overall insensitivity of sclerotinia to three fungicide groups hasn’t changed in a big way between 2010 and 2024 — but shows some sclerotinia populations have been discovered with elevated insensitivity to all three.
In another example, most of the fields on his farm haven’t seen tillage in about 30 years, so when he seeded a new piece of land this year that had been conventionally farmed for many years, he could feel the difference. Pulling his direct seeding drill over this new field required more horsepower than seeding the nearby, more mellow, soil on his longtime zero-till land.
Nerbas has paid attention to soil health throughout his farming career. He and his wife, Diane, have owned NRG Farms Ltd. for about 32 years, producing canola, wheat, barley, oats, flax and faba beans. The farm also included a commercial cow-calf operation until 2021.
Nerbas served as an agrologist with the Saskatchewan Soil Conservation Association (SSCA) for 10 years and he continues to be involved with SSCA as well as the Soil Conservation Council of Canada.
Feedlot beneath your feet
“It has just been ingrained in our thinking right from the start the importance of having crop diversity, which also helps benefit the environment and the natural diversity of the soil,” he says. “Maintaining and improving soil organic matter is vital to crop production and soil health. I consider the soil micro-organisms much like a feedlot — I have to think about feeding the soil biology.”
Nerbas has consistently applied several production practices over the years all keeping soil health in mind. He switched to a direct seeding, zero-till system more than 25 years ago. Crops are seeded with a Seed Master drill with hoe openers set on 14-inch row spacing.
He grows a diverse mix of crops and sticks with varieties that produce high levels of biomass. “I don’t grow any dwarf or semi-dwarf varieties,” he says. “I want as much residue as possible. I let the combine do a good job of spreading chaff and straw and overall residue management.” There is no high-speed tillage or heavy harrowing.
As each growing season adds more crop residue, it adds to a mulch layer or as Nerbas describes it “soil armour” — a layer of organic material that protects the soil. Crop residue and root systems break down to feed soil micro-organisms and organic matter is gradually increased. “I know some people talk about building soil organic matter in just a few years and it just doesn’t happen that fast — it is a slow process,” he says. “But over 25 to 30 years, you do begin to see a difference.”
While the Nerbas farm is relatively flat, there is some rolling topography and fields with knolls and hilltops. These are naturally lower-producing areas with thinner soil and less organic matter content.
Along with keeping as much crop residue as possible on the hilltops, during the years with cattle on the farm these areas were also the preferred winter-feeding sites.
“We made a point of feeding cattle on hilltops to add manure and increase the amount of residue on the soil,” he says. “And we can see a difference there too. Those areas are still not as productive as some of the lower-lying areas of the field, but over the years production has increased.”
Nerbas is always interested in improving cropping and soil conservation practices. He hopes one day to do a side-by-side seeding trial with a disc drill next to his hoe drill just to see the difference in soil disturbance. He’s also keeping an eye on the relatively new practice of adding cover cropping to the rotation to determine if it might be a fit on his farm one day. A lot will depend on whether there is moisture to support later-season growth of the cover crop.
“I am always interested in listening to soil specialists talk about research and practices I may be able to apply on our farm,” he says. “We will continue with our approach of no tillage while maintaining crop diversity and be open to opportunities to learn more.”
Plays many roles
Jeff Schoenau, a soil scientist and professor at the University of Saskatchewan, agrees farmers shouldn’t underestimate the value of maintaining and improving the level of organic matter in soils.
“When it comes to soil health and overall crop production, the level of soil organic matter is extremely important,” says Schoenau. “Organic matter affects so many soil attributes.”
For example, soil organic matter affects soil in the following ways:
- It adds to the water holding capacity of the soil.
- It increases the ability of water to move into the soil or its infiltration of soil.
- Soil organic matter improves soil structure or soil tilth.
- It improves chemical activity and serves as the main store of nitrogen, sulphur and, to some degree, phosphorus, eventually converting these nutrients into plant-available forms.
- It supports biological activity in the soil serving as a source of food and energy to the microbial population.
- Soil organic matter is key to the recycling of nutrients. Between three and five per cent of organic matter is made up of microbial biomass — the living fraction of the soil.
- Organic matter and the microbial biomass also influence carbon sequestration rate.
- Soil organic matter increases the resilience of the crop and its ability to withstand environmental stresses such as excessive moisture and drought.
“Conservation farming practices over the past 30 to 40 years have made a difference in the amount of organic matter and soil health across Western Canada,” says Schoenau.
No-till farming practices, extended rotations, crop diversity, the use of more legumes in rotation, the use of fertilizer at the recommended rate and application of solid manure when available have all contributed to improved organic matter levels.
“I was involved in research that looked at soil samples taken in 1996 and then those same locations were revisited and tested in 2018,” he says. “The 2018 samples showed a significant increase in soil organic matter and much higher levels of soil microbial biomass carbon, which is an indicator of soil health. These are all benefits attributed to conservation farming practices.”
