 Greetings, I'm Chris Augustine, Director of the Dickinson Research Extension Center, and we're doing some work on soil acidity and how to manage that in our acidic soils within North Dakota. We don't have much research right now to give us guidelines on how to fix those areas. We know we need a liming amendment to improve those areas, but our soils are a little different than where most of the research has been conducted in the past. And so we're working with the North Dakota Soybean Council as well as the Northern Canola Growers Association on trying to develop some recommendations for managing these acidic soils. So when we're talking about acidity, we're talking about soil pH, and really it comes down to the concentration of the hydrogen ion in the soil. So to test soil pH, it's pretty easy. You can go online and buy a decent pH tester for $100-150, but when you do that, make sure that you calibrate it and follow the instructions for that particular unit. But when we do it, we're going to run the same test that a soil testing lab would perform. And that's one part soil, one part water on equal volume. So I'm just using a tablespoon scoop to divvy out the soil and the water. So when you use water, you want to make sure you use distilled water. If you use tap water, there's probably some minerals in there that could influence the pH and not give you the true pH of the soil. So we have a couple different cups here. We have regular soil, and when you mix this up, I already did it. It needs to sit for about 15 minutes or so, so it can equilibrate. And this is a standard soil that I picked up from here at the North Central Research Extension Center in Minot. And we'll put the probe in and see what the pH is. So the pH of this soil is 5.1, and 5.1 can be a problematic soil. When we start seeing pH is less than 5.5, aluminum toxicity, and in some extreme cases, meganese toxicity can come into play. So when we manage these soils, we want to make sure that we're putting the right thing down, and we need some sort of liming agent. And we've been using sugar beet waste line that we've collected from the Sydney beet factory over in Montana. And it's important to keep in mind that it's not the calcium in the limestone that's improving the pH. It's actually the carbonate that reacts with the hydrogen ion, produces water, and CO2, and that's what actually does the neutralizing. It's possible you have some calcium deficiencies throughout the state of North Dakota, so maybe a calcium amendment can work from time to time. But if you put the wrong product down, you can actually exacerbate the acidity. So we have two cups here, one that we put gypsum in, which is calcium sulfate, and another one that we put some lime in, which is calcium carbonate. And what happens with the gypsum is as that dissolves in the soil solution, the calcium is freed up, it binds to the cation exchange sites, and then hydrogen is released from those exchange sites within the soil. So that can actually decrease the acidity, or increase the acidity of that soil even more. So we'll try this with the gypsum. And so it was originally 5.1 with the standard soil. And we've decreased this pH to 4.9. So now this is on the lines of where we would maybe expect some manganese toxicity as well as the aluminum toxicity. The aluminum toxicity will start at like a pH of 5.5, but the manganese toxicity usually starts once that pH is less than five. And so I took that soil again, but this time we put lime in. And lime is what reacts with the hydrogen and which can raise the pH. And for this demonstration, I just used a tablespoon or so of each amendment. And we've increased the soil pH to 6.3. So this is pretty much the ideal soil pH. And so what happens when we increase the pH, aluminum is still in the soil, but the concentration decreases. Our soils have lots of aluminum, because our clay minerals are made up of aluminum and silicates. And so it's in the soil, but until that pH gets below 5.5 it's, they're more so physically and relatively chemically inert. And so when aluminum comes into the soil solution, when that pH is less than 5.5, it can free up, bind to cation exchange sites, release more hydrogen, which can decrease the pH. But then it also has the ability to split water in half. And it releases hydrogen during that process and the OH of the H2O binds to the aluminum. And where we really see aluminum toxicity is you need the pH of 5.5 or less. But you also need to have about 25 parts per million or more of exchangeable aluminum. And so in this graph, we show how as we increase the amount of lime, we decrease the amount of exchangeable aluminum within that soil solution. Some of the things that you'll see with aluminum toxicity, these are some soybeans that I pulled from our plots. The ones in my left hand, that is from four tons of beet lime. The pH here was right around 6.2, 6.3, something like that. And then these smaller soybeans in my right hand, that pH was somewhere around 4.7, 4.9, somewhere in that realm. Other things that you notice besides the size of the plants, these soybeans are starting to get some nodules on them already. And one of the things that happens when soils become too acidic is bacteria activity in the soil can greatly decrease. So the rhizomious bacteria that fix the nitrogen of all of our legumes in North Dakota, that can be hindered with these extremely acidic conditions. So we may see some nitrogen deficiencies. Aluminum can also tie up phosphorus, so it's possible to see phosphorus deficiencies in these soils as well. So a couple of weeks ago, we actually saw some manganese toxicity in these plots. They're starting to grow out of it, but when the plants were much younger, it almost looked like a potassium deficiency, where the leaves on the edges had a necrotic look to it. But there was also a blistering look to it, which is characteristic of the manganese toxicity. Where the shorter canola is, that was an untreated check. And again, the pH was about 4.8 or 4.9 there. And where this taller canola is, the taller canola received four tons of beat lime. And you can definitely tell that there's a difference in the emergence as well as how healthy the plants look and how big the plant looks. So we'll wait to see what the combine tells us. But right now, there's definitely a visual difference. So in the foreground, these soybeans were untreated. So the pH of this soil was 4.8 or 4.9. You can see that we had sporadic germination. This is where I pulled those plants, where the plants were definitely stunted. But as we go to the background, those are where our different lime treatments are. And so where the soybeans really start looking nice, that is four tons of beat lime. And at the way back of this plot, that received eight tons of beat lime. Managing these soils, really, you just need to make sure that you're putting the right stuff down. You need to put some sort of liming agent, whether that's dolomitic limestone, calcitic limestone, waistline from a water treatment plant, or a sugar beet factory. Those are the things that can increase the soil pH. If you put on the wrong amendment like a calcium chloride or a calcium sulfate, that can decrease the soil pH.