It’s National Soil Conservation Week, and today is Earth Day.
Farmers and ranchers play a very important role in soil conservation and helping to improve the health of our soil.
Over the years, producers have modified some of their practices as a way to improve the soil.
For farmers, some of the practices include crop rotations, practicing 4R nutrient management, managing salinity, and the move to zero-till farming or direct seeding.
Ranchers focus on soil conservation through practices like cover crops, erosion control, winter grazing and monitoring stocking rates to reduce overgrazing.
Dr Barbara Cade-Menun, a research scientist with Agriculture and Agri-Food Canada at the Swift Current Research and Development Centre says it's vital that we take good care of our soils.
She points out that we need to understand how soils function and what we're doing to them so that we do practices that are beneficial.
“Conservation practices are aimed at increasing carbon in the soil or maintaining it. That's a good thing. We have to remember too, that some of those might have some unintended consequences. And because we may have changed some of our practices to conserve carbon, but not necessarily changed practices like fertilization. So health is more than just how much carbon we have in the soil. It's all about how the soil functions at its prime to do everything it needs to do . So nutrient cycling, if nutrients are, for example, too high and they're being lost to run off, that's not a healthy soil, because it's polluting the water downstream. So everything together is important.”
Part of her research focus now is looking at how prairie soils are becoming more acidic from where we’re putting our fertilizer.
She says while we’ve stopped using tillage to mix everything through, we didn't change the practice of how we put that fertilizer in.
“So, particularly when it's dry and particularly in soils, not so much in Manitoba or any soils that are high pH, like over 7 or 8 but the soils that are naturally about 6 ½ or below are becoming much more acidic. Particularly, the top 10 centimeters of the soil, because that's where we’re putting the fertilizer. We're not mixing it in the soil, so it sits there.”
In some of the long-term plots at the research station, they're seeing the pH in the top ten centimeters below 5, but then it goes back down lower than that. Where they are doing tillage, it's staying at 6 1/2, while in the organic plots it's closer to 7.
She points out that parts of Alberta, Montana and the Northern U.S. states have all recognized this as well.
“We need to pay attention to this and figure it out. If we have to change our practices in terms of fertilizers, or if we have to start doing some liming.”
Cade-Menun's key area of research is on phosphorus nutrition which is really sensitive to soil pH.
She's currently involved in a project that's funded by Saskatchewn ADF that's looking at this and its link to disease.
“A lot of disease organisms like acidic conditions, so looking at it in conjunction with root rot. It's an interesting component that we don't think about: that by changing one thing, not tilling, we may have introduced something else. So, we want to keep all the soil carbon in there, but we also want to make sure that we don't make the soil hostile because we change the pH. That's what makes soils fascinating but complicated. It's just a lot of different things going on at the same time that we have to pay attention to."