Most farmers can agree that although there’s no silver bullet to a bumper crop, healthy soil plays a crucial role, from seeding to harvest and beyond. But how much is understood about what really happens beneath the surface of the field?
“Well-functioning soil will retain, provide and recycle nutrients and water, and will support a diverse array of biota in the soil-plant system,” explains Jeff Schoenau, professor of soil fertility at the University of Saskatchewan and the Saskatchewan Ministry of Agriculture chair in soil nutrient management. “This contributes to greater productivity and greater yield. Greater nutrient and water use efficiency from applied fertilizers and water reduces input needs, helping profitability.”
To really grasp how well soil is functioning, Schoenau says regular soil sampling is a critical step to assess different indicators, like organic matter content – a reservoir of important nutrients like nitrogen, sulfur and phosphorus. “Microbial populations, including their biomass, diversity and activity, can be measured and supply of available nutrients released over time are part of the soil health picture too,” he says.
Schoenau adds that traditional indicators, like pH and salinity, also point to the quality of the soil, as do the physical condition of the soil – especially in regions that experience extreme weather conditions.
“Soil aggregation and aggregate stability are indicators of good soil structure, as is the ability to resist wind and water erosion, which is sometimes included in soil health assessments alongside water infiltration,” he notes. “When we lose topsoil, that topsoil is rich in the organic matter and clay that contributes to fertility, biological activity, structure and water holding capacity.”
Above all, a good sampling plan must account for variation in soil properties that occurs across a field due to factors like landscape elevation, slope, and surface curvature, water redistribution, residual fertilizer in bands and past management practices. And while extreme conditions like drought will impact soil health, Schoenau says, healthy soil contributes to a resilient crop, acting as a protective shield against environmental stresses and ensuring productivity for years to come.
That’s why, for farmers like Pat Kunz, soil health is part of an ongoing succession plan.
Kunz runs a mixed farm in Beiseker, Alta., northeast of Calgary, with his wife, father and some seasonal help. The farm comprises a cow-calf operation, feedlot and several hundred acres in a wheat, canola, barley and pea rotation.
“Everybody talks about sustainability, and that’s the only word to use here,” Kunz says. “This is a family farm that I’m in the process of taking over. I’d eventually like my own kids to be able to farm the same land.”
Soil health for generational sustainability
For more than a decade, Kunz and his family have worked with Garth Donald, manager of agronomy at Decisive Farming by TELUS Agriculture, to develop sustainable nutrient plans for the farm. Like Kunz, Donald says that beyond increasing yield and profitability, healthy soil contributes to the longevity of the family farm.
“This is about handing the soil down from generation to generation,” he says.
To start, Donald says he goes back to the tried-and-true way of measuring soil health by looking at it with his own eyes. “I’ll put a shovel into the soil and see what’s there,” he says, noting he looks for things like earthworm activity and soil tilth.
But, he adds, the human eye fails to dig deeper, and can’t pick up on other soil health indicators that a microscope would see.
“In years without moisture, like what many parts of Western Canada have experienced, that dry soil slows down microbial activity, meaning the nutrient breakdown doesn’t occur as quickly. On the other hand, wet conditions affect soil structure, which also contributes to soil health.”
Donald echoes Schoenau’s recommendation about regular soil sampling to get a handle of what’s really happening under the ground.
“Without knowing what your starting point is, you’re going in blind,” he says, noting how difficult it is to make agronomic decisions without a data set to back it up. “While soil testing isn’t exact, it’s a snapshot of the soil, and working with producers, we can come up with a plan.”
You deserve healthy soil
A GPS-based soil test, like Sure Check offered by Decisive Farming, involves a soil technician pulling 12 to 14 cores of soil from a GPS reference point and sending it to a lab to be analyzed for more than 20 different characteristics. This creates a benchmark dataset to return to and compare against every year. Once the results are back from the lab, the farmer works together with an agronomist to determine the next steps, using the data to tailor fertility and seed plans accordingly.
“Instead of peaks and valleys in your data, this type of test is a gentle wave curve that’s a realistic measurement,” Donald says. “But it’s a narrower view, like looking through a pen, it’s a snapshot, not a full picture.”
In an ideal world, these samples are best taken as close to the time of crop demand as possible, as that leaves little opportunity for nutrient levels to change from the time of assessment until plant growth begins, Schoenau notes. “However, sampling, getting an analysis back and developing a plan in that very short busy time frame right before seeding is not always practical,” he adds. Schoenau says that much of the sampling, analysis and plan development can be done in the fall once the soil has cooled. “A few checks may be done in spring to see if there are any changes, which can be important to know and adjust for, such as nitrate losses in a very wet, early spring period.”
For building long-term data, Decisive Farming’s Optimize RX uses variable rate technology to collect soil, water and topography data to provide zones within the field, taking samples from a larger area and providing a wider look at a field. Donald emphasizes that this is a multi-year approach, which can include satellite imagery maps to make site-specific plans for fertilizer and seed. He has worked with the Kunz family to use variable rate programs for more than a decade to help boost yield and reduce fertilizer use by using only what’s needed.
To get started, Donald says a farmer should work with his agronomist and decision-making team to determine what solution is best and most efficient for the farm operation. “Variable rate becomes a cost challenge if the farm doesn’t have the right equipment,” he adds, emphasizing the need for collaboration when it comes to soil health. “While an agronomist or sales team can make recommendations, the farmer’s perspective is paramount for adding real-life experience, ensuring the final plan is realistic and achievable for each individual farm.”
Kunz agrees. “It still comes down to logistics – we need to do the best we can with what we have, and every farm is different,” he says, noting small steps to improvement can make a big difference year over year.
“We haven’t reached a pinnacle way of farming – it’s continually evolving. We’re not going to farm the same way in 20 years that we do now,” Kunz says. “But at the very least, you need to put back what you take out of the soil – or ideally, improve it.”
For more information, visit decisivefarming.com/Soil-Health.