Carbon Cycling in Cover Crops: What Livestock and Plant Combinations Teach Us

0:08 Okay so if you're gonna move to a second paddock, what would you do? Would you make some changes—higher stock density? Or let's say we—and you could do that two ways, right? Either let's add livestock or you could shrink the paddock. As ideally you'd like to be a nice trample. If I don't get a nice flat trample, the next paddock's can be smaller. It was too big. Okay, so you start adjusting those type things.

0:41 There's a couple of questions for you. Dig me out a plant with you. Okay, so let me ask you this question: how do you get carbon in your soil in the rest?

1:03 Say again photosynthesis? Yeah, and how.

1:08 Much carbon, how much CO2 is in the atmosphere? Not near enough. How much is in the atmosphere? 410 parts per million. I think that's pretty close.

1:22 I took a reading earlier this morning underneath the canopy was 423, underneath the canopy, and right now it's reading 409. So you're way off.

1:39 So how does that CO2, how does that carbon get in our soil? It's gonna come into the stomata, isn't it? It's gonna, and then the plant is 42 percent carbon, so it builds itself above and below. And then gives off the exudates, exactly, the sugars into the soil. And we start to have that process.

2:01 Now under that canopy was a little higher. Why?

2:08 Yeah, his respiration going on obviously because that CO2 coming out of the soil is going to come from the respiration of the biology and it's also going to come from the decaying of every plant part that had carbon in it, okay. Over time, so we have that starts at the scenario starting, but a plant has to harvest it through stomata in order for that to work. We have to have a stoma open during the daylight. We got the bigger leaves we have, the more of that you're going to harvest. So we have a big solar collector as well, and then the plants going to give it off as carbon exudates.

2:42 Now, if we had come in here earlier, that's another thing we'd like to do. If we had livestock, right, we'd like to be.

2:48 An ear earlier would it be a little more vegetative and we would come in and top it and so when you type it what's going to happen to the root mass of these plants? Yeah, some of that's going to die off a bit. We're going to give some carbon because there's carbon in the root mass as well. We're going to give that off and so we're going to move it. The plants going to regrow, let's go to regrow and we end up harvesting more carbon than if we wouldn't have grazed it. Okay, that's one of the big reasons why livestock are such a great tool if we have that situation occurring. No, on a typical plant a third of the carbon is going to be in the residue, third is in the roughness, third is in.

3:30 The grain normally gets wheels under it, right? It's going to go for ethanol, it's going to go for people food, or if you go for livestock food. Normally gets wheels under the third that's above ground. If we can get a trample like this, we got a chance at extracting some of that. Why is the trample more helpful than when it's standing up? So I'll contact because now it's touching the biology, isn't it? So it gives us a better swing at the ball. Normally what you're going to get is roughly 30% of the root mass if you're not going to till it, which you're from Nebraska, so there's all no tillers, right? That's my understanding. They told me that when they came, the third of the.

4:17 Carbon that's in the root mass you're gonna capture about 30% of that. If you're no tilling you're gonna capture about 15% of the above ground. But if you're going to graze, that's a game-changer. Now you got a whole another tool that you're applying.

4:32 The third that's in the grain we think we're probably gonna lose that. So we talked a little bit about fibrous. The fibrous root mass is what's going to build the soil aggregates because when it gives off those exudates into the soil, the biology is going to build the soil aggregates on the root mass. Fibrous root mass typically after it builds very little for soil aggregates, but if you put the two—

5:00 Together the tap throat's gonna build the macro pores and this is going to build the small microscopic pore spaces. Okay so the two together it's just one of the reasons why combinations of plants, just one of the reasons.

5:14 Now also something that some people used as an aid is bricks. This is not your normal juice collector. They will normally tell you to get a garlic press and that's okay but we customized the garlic press just a little bit and so we go ahead and clamp this down. Actually USDA uses this in their staff meetings to convince us to do various things, okay.

5:44 Let's see if we can get a little juice out of there. If not we have to clamp it down a little bit more as nothing coming.

6:51 Little later in the day this is going to go up more because the plants getting in full gear. Plant maturity, it's blooming also right now, so it's peak peak sugar versus something that's just sprouting. It's not producing as much photosynthesis, so there'll be a big difference. The definition here too of the Brix: higher the Brix, higher the sugar content, mineral content, protein content, and greater overall nutrient density. That's the process. So it just kind of gives you an idea the beauty of the refractometer is there's no battery, there's nothing to plug in, there's nothing to download, just use it so it works. And also, you know, there's nothing special about a CO2.

7:36 Meters but if we all win inside say at noon we're all inside a building, okay? We're all inside the building, what's the CO2 reading going to do? Go up because we give off. We start to understand that process.

8:06 One of the beauties too about putting these combinations in is here we got a classical case of a high carbon plant and a low carbon plant, and soybean plant is probably what I was actually more interested in talking to you about because more recently in the Northern Plains what we're starting to do more—well, first of all we're growing way more soybean now than wheat, okay? So are we.

8:29 Dave has gone way down or soybean acres way up. So what right, so what you got to think about that when we do that on the landscape because what we're replacing is a very high carbon plant with a very low carbon plant. Neither plant is evil but the difference is one brings a lot of food carbon to the soil biology to build these soil aggregates do these functions one brings a much smaller amount. So when we have soybean growing repetitively we have good collapse soils. This is not uncommon.

9:07 Yeah so one way to offset this is we've been planting soybean green as much as we can and so we'll put in the triticale or the rye into whatever is growing the year before it's corn. That's a pretty

9:21 Good one to intercede into, we can get it started later in the fall. We can even go ahead and put it in after harvest on some of our crops. Then we go ahead and we plant green into a soybean, green into it in the spring. We also plant canola green, pinto beans green. That gives us a whole other start because our Northern Plains is a little different than your environment here. Our season is shorter and our days are longer. We have more sunlight during the summer in a day, but our season is shorter, so when it happens it's real quick.

9:54 Give us a long fall for the cover crop in, so we got to be real timely about that aspect of it. But what a game-changer because now we can go ahead and add additional carbon to the soybean crop and it's fibrous, so it's going to build soil aggregate.