Mike Howell (00:08):
The Dirt with me, Mike Howell, an eKonomics podcast where I present the down and dirty agronomic science to help grow crops and bottom lines. Inspired by eKonomics.com, farming’s go-to informational resource. I’m here to break down the latest crop nutrition, research, news, and issues. Helping farmers make better business decisions through actionable insights. Let’s dig in.
(00:39):
Well, hello again everyone. Welcome back to the Dirt. We got a new topic for us today. We’re going to be talking about soil salinity. Now that’s something I don’t deal with an awful lot here in the Southeast part of the US, but it is beginning to become more and more of an issue in certain places. But we’ve got two experts here with us today that are going to share their experiences with soil salinity and help us get more familiar with that. We’ve got Lyle Cowell and Alan Blaylock. Now, both of these gentlemen are no stranger to the Dirt. They’ve been on multiple times over the years, but I’m going to let them take a few minutes and reintroduce yourself to you. Lyle, if you would, remind our listeners where you’re located and what you’re doing for us.
Lyle Cowell (01:15):
Well, thanks for having us again, Mike. So Lyle Cowell, just up here in Saskatchewan in Western Canada. Work as the Canadian agronomist with Nutrien, and as you said, soil salinity is a very big deal in Western Canada. Not so much in the east, but a very big deal in Western Canada. So look forward to chatting with you about this topic.
Mike Howell (01:34):
And Alan, welcome back. Remind our listeners where you are and what you’re doing.
Dr. Alan Blaylock (01:38):
Thanks Mike. A pleasure to be here again. I’m senior agronomist with Nutrien in the US. I’m based in Colorado, and spend much of my time in the Western half of the US, and in this part of the world, soil salinity is a big issue. We have many challenges, particularly in our irrigated areas with salt accumulation from irrigation water.
Mike Howell (01:58):
I know both of you have done a lot of work with soil salinity. Both of you have got a paper or two that’s on our eKonomics website. So let’s dive right in and start talking about soil salinity. And I guess the first thing we need to figure out is what is soil salinity? Alan, do you have a good definition of soil salinity? Let everybody know what it is exactly.
Dr. Alan Blaylock (02:17):
Well simply put, Mike, soil salinity is the salts that are in the soil solution. As minerals weather, they release soluble minerals into the soil solution, and those are in the form of salts. As those accumulate, they may, in certain circumstances, accumulate to levels that could become limiting to plant growth, and there are certain salts that may impede our ability to manage the soil properly. I’m sure we’ll get into some of those effects later on, but it’s simply the accumulation of soluble minerals in the soil solution.
Mike Howell (02:48):
Now while we’re talking today about soil salinity, but another closely related topic is soil sodicity. Tell us what the difference in the two is.
Lyle Cowell (02:57):
Well, as Alan said, in general, salinity is the accumulation of ions in solution. Sodicity is driven by high levels of sodium. Sodium brings with it extra baggage, and negative baggage, in terms of soil quality in reducing the soil structural quality. In Western Canada, we deal primarily with sodicity when we have solanetsic or salotic soils, very, very dense, difficult subsoils that can’t be penetrated by water or roots or tillage equipment. We don’t really have any true sodic soils in Western Canada in terms of the topsoil, but we certainly do when we look at our solanetsic soils.
Mike Howell (03:34):
Well, you already mentioned that you see this in Western Canada, not so much in the Eastern half of Canada, but generally speaking, are there areas or regions that we have more of a problem with soil salinity than other areas?
Lyle Cowell (03:46):
Yeah, absolutely. Eastern Canada is a very minor problem. And it comes down to the origin of the material that’s on the surface of the soil, and the subsoil, and actually to layers well below that. So it depends largely on the climate and then the soils within a given region. Tends to be more severe in arid climates, but where high accumulations of subsoil water develops within that arid climate, bringing those subsoil salts to the surface. In Western Canada, the most severe regions would be generally in Central and Eastern Saskatchewan and into Eastern Manitoba, and then sporadically through Alberta. Alberta is a little harder hit by solanetsic soils. We all have some salinity throughout Western Canada, well over several millions of acres already affected, and probably a growing problem. But that’s generally the geography that we’d see it within.
Mike Howell (04:39):
Alan, what about in the US?
Dr. Alan Blaylock (04:41):
Yeah, so Mike, I would add to Lyle’s comments that the areas where we’re most prone to salt accumulation, both salts in general and specific to sodium, as Lyle mentioned, are areas where we have high water tables, so the water is closer to the surface and evaporation will continue to bring that water up to the surface. That water, as it moves, carries salts from the subsoil up to the surface. Shallow, uncontrolled water tables tend to be one source of soil salts and high evaporation rates. So in the Western US where we have primarily arid and semi-arid areas, you have high evaporation rates, so you tend to get salts accumulating at the surface.
(05:21):
The other source of salts that tends to be a problem is certain irrigation waters. This is something we’ll talk more about in terms of prevention, but all of our surface waters, and especially well waters, contain some dissolved salts. And as we apply those waters to the soil surface for irrigation, we can produce an accumulation. We couple that irrigation with high evaporation rates. That can lead to accumulation of salts. This can be a specific problem. Those are the two primary sources of soil salinity is uncontrolled water tables closer to the surface, and salts from irrigation coupled with that high evaporation that keeps those salts moving to the surface.
Mike Howell (06:01):
Alan, we’re talking about the problems with soil salinity. We probably need to define what the problems are, what kind of symptoms are we seeing or what do we look for in the field that will indicate that we have a soil salinity problem?
Dr. Alan Blaylock (06:13):
Well, one of the most visible symptoms that you see with greater salt accumulations, as you can see, some white crusting on the surface as salts accumulate, and so that’s an obvious symptom. It’s common in more severe cases, but we oftentimes don’t see that. One of the primary effects of salts on plants is impairing their ability to take up water. The salt tends to draw that water. The salt wants to be in water and creates, what we call, an osmotic stress on the plant. So it’s harder for the plant to take up water from the soil, so that’s one of our symptoms is apparent moisture stress or drought stress when the soil actually is maybe fairly wet. Salts simply impair the ability of plants to take up water.
(06:53):
So that’s one of our primary effects. Another effect is the sodium problem that Lyle mentioned. When we get high levels of sodium in the soil, it starts to disperse the soil clays, so pores clog, the soil crusts over, it becomes less permeable to water. So poor physical condition, that’s another problem. The third basic effect of salts is we may have some specific salts that can be toxic to plants. Now oftentimes we’ll reach a limiting total salt load before we get to those toxic levels, but elements like chloride, boron, sodium, can accumulate to toxic levels in these salt affected soils or saline soils. So that would be another one that we would want to be concerned about, and you can actually measure those in your soil test.
Mike Howell (07:37):
Lyle, anything to add on that?
Lyle Cowell (07:39):
As Alan said, this is largely an effect on the ability of plants to take up water, and often in an environment where there’s often drought to start with. We’re often adding on a drought stress on top of conditions that is dry already, in terms of the growing conditions of the region. As Alan said, you will start to see significant yield losses and reduced plant growth before you see the outward effects on the soil with the salt accumulation on the surface. Alan mentioned the high water table, and it’s often a bit of irony that these very, very saline areas are often also very wet. The plants are suffering from an inability to take up water in an environment, that if you drive your truck across it, you might get stuck. It’s just an imbalance of salts with the ability of the plants to take up that water.
Mike Howell (08:26):
Lyle, as you were describing that I couldn’t help but think about being stranded on an island out in the middle of the ocean, plenty of water everywhere, but not a drop to drink. Is that kind of the same situation?
Lyle Cowell (08:36):
It really is. And then it comes down to the ability of the plant species, the crop species, to tolerate that salinity. A lot of our annual crops are quite intolerant of salinity, starting with they have to germinate every year, so that’s a sensitive stage of being able to absorb water. There’s many forage grasses, for example, that can tolerate very, very high levels of salinity. And in that case then they can access the water that’s available within those regions. So the impact of salinity on the crop will depend largely on the species of the crop. In some cases it may be a levels of salinity that a lot of annual crops couldn’t grow at all, and yet you can have a very productive forage crop.
Mike Howell (09:16):
The Dirt is your home for agronomic topics that boost your crop knowledge and profitability, but it only scratches the surface on what eKonomics has to offer. See for yourself why eKonomics is known as farming’s go-to information resource. Check it out at nutrien-eKonomics with a k.com. Well, we’ve kind of mentioned this a little bit in passing, but let’s take a little deeper dive into this. Where does soil salinity come from? Alan, you mentioned earlier that irrigation water could be a source, but I know there’s other ways that we can incur this problem. Tell us a little bit about where this situation comes from.
Dr. Alan Blaylock (09:55):
Well, it’s simply minerals, mineral forms, that are soluble salts in the soil. They may come from long-term soil weathering. Sometimes we can have, what we refer to sometimes as saline seeps, where water is flowing down through the soil in one area, moving laterally underground and seeping out on a side hill, for example. Those are common areas where we see the salt accumulation. I’ve seen those many times in the field. Also mentioned the irrigation water. But we have to look at sources of the salts. And one of those sources could potentially be fertilizer. Fertilizers are soluble salts. We put them in the soil. The goal is to get them taken up into the plants, but there may be cases where, over time, we get an accumulation of some excess elements, and particularly when, as Lyle mentioned, many of these crops are more sensitive during germination and emergence.
(10:46):
So if we have too much fertilizer too close to the seed, that can impair the germination of the seed, and that’s a salt effect. That’s the salts in the soil solution impairing the ability of the seed to take in water and germinate. We may not have a high total salt load, but we can certainly have salt effects as a result of how we manage the fertilizer, where we place the rates, if we’re fertilizing, let’s say, some of the high value crops when we’re applying very high rates of fertilizer on a continual basis. If we don’t have good drainage, and we don’t have proper fertilizer management, particularly, we don’t want to apply excesses of fertilizer, but these are some potential sources of salts in the soil.
Mike Howell (11:25):
Alan, you mentioned that fertilizer could be a source of this salinity, and here in the southeast I usually don’t run into this problem. In fact, I think I’ve only seen this problem twice in my career, and both of these went back to a fertilizer application. One application, the grower had put all of the fertilizer he needed for the entire year, and some of this was man-made fertilizer. Go to the store and buy a bag of fertilizer. Part of it was manure that he had incorporated into the soil, but he had put all of this fertilizer out within a couple of weeks of planting time and it turned off really dry.
(11:56):
We didn’t get any rain to flush those salts out of the system, and he had a pretty bad stand failure and had a bad crop all year long. Another one was closer to home here in Mississippi, and they had side dressed some sweet potatoes with fertilizer and then it turned off really dry, and we weren’t able to flush the salts out of it that way. So those are the two situations that I’ve ran into and it always comes back to a lack of water in my part of the world. Typically, if we get rain, we can flush those salts out of the system. But that’s not the case where you two are located for the most part. You just don’t get the rain to flush them out ever. Is that kind of the way I’m seeing this?
Dr. Alan Blaylock (12:30):
Yeah, and Mike, I’m glad you brought up the subject of manures. That was a source I failed to mention. Particularly if we’re applying high rates of manures on a regular basis, you’ve got a feeding operation of some kind, and you’re putting that manure on the field. Manures can contain pretty high levels of salt, so that’s something we want to pay attention to if we’re using high rates of manures. I’m glad you mentioned that. But yes, mike, water, rain or irrigation can disperse those salts, move them down through the root zone. And keeping in mind that some of these salts are plant nutrients, we’re kind of walking a line there between potentially losing plant nutrients and trying to eliminate the salt problem, but moving water down through the root zone is really the only way we can get rid of those salts, disperse those salts. Otherwise, they tend to accumulate. On a long-term basis, maybe not with each event, but certainly if you are in an area prone to salinity, you have to somehow facilitate, on a long-term basis, more water moving down through the root zone than is accumulating.
Mike Howell (13:30):
That brings up another point, and I don’t really know exactly a lot about these products, but I do know that some people are promoting products that you can apply to the soil that’ll help with this problem. It’ll help move those salts out. Do either of y’all have any experience with any of these products? Do they actually work? Lyle, let’s start with you.
Lyle Cowell (13:48):
Well, they usually work really well if it rains the day after you apply it. That’s the thing. As Alan said, the solution is groundwater control. If you have a significant rainfall, or in Western Canada, snow melt, it’ll move the salts out of the rooting zone or out of the seed-bed. And it’s all about water movement. Salts move up or down with water. And trying to sell someone a product to alleviate this, it’s just logistically and chemically impossible to do. I would add one solution that you can control the water table and I come back to forage grasses. Probably the most practical means of controlling the water table in Western Canada is growing a crop that can tolerate salinity and therefore utilize that groundwater.
(14:33):
And that’s by far our most effective means of controlling salinity in Western Canada because we don’t have a lot of excess rain. We rarely have leaching of any nutrients below the root zone, and we don’t have access to irrigation water across much of the areas that are saline, so it becomes difficult that way. But deep-rooted forage grasses, if they use up a lot of that groundwater, it helps contain the salt level to a deeper level in the soil and also helps prevent the water and salts from moving to the surface beside where those forages are growing. So buy some forage seed for Western Canada. Nothing else that someone can sell you in a bag or jug is going to help you.
Mike Howell (15:10):
Alan, anything to add to that?
Dr. Alan Blaylock (15:13):
Yeah, I would like to add a couple of things. There are some specific cases where certain materials can be helpful. Now, one of those that’s maybe the best known and has been well-studied, is when we have high sodium accumulations, we have to displace that sodium with a calcium amendment. So gypsum is often used to displace the sodium. Gypsum is a calcium sulfate that dissolves, the calcium is adsorbed to the cation exchange complex, preferentially over sodium, so we’ll displace the sodium, push it out into solution, and then we can move the sodium down out of the profile. So that’s a case where an amendment could actually be beneficial. As Lyle says, there’s no chemical we’re going to apply that can say neutralize these salts. The salts are there, there’s nothing we can really apply to neutralize them, but in the case of gypsum displacing sodium, that is an amendment that can be beneficial, if you’ve identified that it’s a true sodicity problem.
(16:07):
Another one that is being studied more recently, that may have some promise, I think there’s still something to learn. There are some biostimulant products that are claiming to enhance salt tolerance of plants, help decrease their moisture stress, their salt stress. I’ve seen some evidence of this, but I think there’s a whole lot more to learn, and I wouldn’t just go start buying biostimulants for a saline soil. I think Lyle’s suggestion of planting a salt tolerant crop is that’s your first best defense if you can’t control the water. Also, keeping in mind that if the source of the salts is a high water table, you’ve got to fix that. You can’t leach salts out if you have a high water table.
(16:46):
You either have to do something to extract the water, like Lyle mentions, growing a crop that will consume a lot of that water, like a forage crop that produces a lot of biomass, use a lot of water, very effective at that. The other option is physical drainage, installing some kind of tile drainage, lowering the water table so those salts can then move down. But until you control the water table, you can’t effectively leach those salts from the upper part of the soil and get them out of the rooting zone of the crop. It’s a physical problem, usually. Salt accumulation is a result of a physical problem related to water, and you have to fix that. Oftentimes, these are some of the most difficult soil problems to correct.
(17:23):
We can lime acid soils, we can use fertilizer on nutrient depleted soils. We can amend with organic materials, and that’s something also that can help with salts and water relationships, but really this is a physical problem and they’re difficult to repair. Sodic soils are some of our most difficult soil problems to correct and require both physical and, in the case of sodic soils, a calcium amendment. The fix is not quick and it’s not cheap, with the exception of maybe planting a forage crop, but you have to have an economic return on that crop. Converting that to feed or grazing in some way, that’s your economic return, but you may not be able to grow the kind of cash crop that you desire in some of these cases.
Mike Howell (18:03):
Lyle, you mentioned it, and Alan confirmed it, planting a deep-rooted forage crop to help with this situation. And this is my ignorance on the topic, I just haven’t dealt with this very much. Can we grow a forage crop and help remove some of these salts so that we can grow a more traditional row crop, or do we need to keep that in forage crops for the duration to eliminate this problem?
Lyle Cowell (18:24):
The amount of salts that you would actually remove with the forage harvest is insignificant relative to the amount of salts in the soils. For a farmer, that’s what their hope is. “We’ll grow a forage crop here for a decade and then everything will be good and we’ll grow canola and wheat after that.” It will work for maybe a year or two. It’s not because you’ve removed the salts, but because the salts are deeper in the profile. Eventually those salts will return back to the surface and will be back to square one. They can be productive, economically productive. In the end, a lot of these saline soils, farmers lose money on every acre of them anyway. If you convert them to forage crops, at very least you stop losing money in those areas. And they can be very productive in terms of hay production, and there is a market for it almost every year in Western Canada.
(19:10):
We really shouldn’t be short of hay in Western Canada if we simply converted our saline soils to forages. And add on to this 1.2 that a lot of the saline systems in Western Canada are artesian systems, and you just can’t fix them. These are systems that are hundreds of kilometers or miles from source of water to the exit into the surface. For example, the Quill Lakes Basin in Central Saskatchewan, one of the largest internally drained systems in North America. These are just systems that you just cannot fix. The size of the system is too large to turn around. So you have to face each one of these systems and understand your local conditions, and be realistic in what the outcome will be. That’s, by and large, is the only solution that you have for farmers.
Mike Howell (19:57):
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(20:20):
In preparing for this episode, we had a discussion going back and forth about how we actually measure the soil salinity, and in my part of the world, if we just run a soil sample and send that to the lab, we’re not going to get any measurement at all about soil salinity. It’s that rare of a problem. We have to specifically request that when we send it to the lab. Alan, is that something that they typically test for when you submit a soil sample in the Western part of the country? And tell us a little bit about how they measure that at the lab?
Dr. Alan Blaylock (20:46):
Sure, Mike, that’s important to understand, and I would say yes, generally most of our Western North American labs will routinely run a measure of soil salinity on any sample that’s submitted. The basic soil test includes things like pH and organic matter and some basic nutrients, and in our Western labs a measure of soil salinity. So yes, that’s fairly common out here, because salinity is such a common problem, so you want to track that. There are different ways of measuring soil salinity. One of the oldest standards is what we call a saturated paste extract. And you simply take a sample of soil, you saturate it, and there’s certain criteria for that. It’s an artsy type of thing. You have to recognize what that saturation looks like and the nature of the soil when you’re making that in the lab, and a technician will be stirring that up and adding a little water, a little water, a little water, till you get it just right.
(21:40):
It’s a difficult procedure to use in a commercial laboratory, but that’s the standard against which most of these things are calibrated. But because it’s so difficult to run in a commercial lab, we use other methods, like a one-to-one soil water extract. So you mix that up and extract that, or even a two-to-one ratio. So that’s an easier way for a commercial laboratory to do that. They don’t have to worry about just the right saturation point. But in either case, the soil solution is extracted and then we measure salinity, the salt concentration in that extract. And there are conversions from these other methods back to the saturated paste. So when we look up some of the tables, for example, we want to look up the salt tolerance of a specific crop, that’s usually calibrated against that saturated paste extract, and so we have to make an adjustment to one of these other techniques, to adjust for the proper salt level, but there are factors available to do that.
(22:33):
There are also some direct measures. There are instruments, salt meters, so to speak, that you could place into the soil or just electrodes that can measure that solution. Those are really useful for measuring salts on an ongoing basis, but again, that has to be calibrated back to these known tests like the saturation extract. But that’s primarily what we’re looking for. In that saturation extract, we can also measure things like bicarbonates and sodium, and some of these other potentially toxic elements that may occur on a less common basis. But that’s the basic method against which most of our standards are calibrated.
Mike Howell (23:08):
Okay, and Lyle, we’ve talked a little bit about some things we can do to manage this problem, but I’m sure we’ve missed a few in our discussion here. So let’s take the next few minutes and talk about different ways that we can manage this problem. What can the grower do if he knows he’s got a soil salinity problem?
Lyle Cowell (23:23):
We’ll start with the soil sample, as Alan described, with the one-to-one ratio. It’s easy to measure, it’s inexpensive to measure. When you’re selecting a soil sample package to have done at a commercial lab always includes salinity. It gives you a lot of clues to other aspects of the soil as well. For example, in Western Canada, almost all of our salts that drive salinity are sulfate salts. This is our first clue as far as managing sulfur in Western Canada. There’s often hundreds or thousands of pounds of sulfur per acre. This then takes us into some of the management of the saline areas. It can lead to decisions on what crop to grow, whether the crop is tolerant or not of that specific area. It can also lead us into different management in terms of soil fertility. If you have a field where the marginal soils are driven by salinity in Western Canada, then you can start looking at variable rate application of sulfur, for example.
(24:18):
You will not need to apply sulfur in saline areas, but there might be a significant portion of that field that does require sulfur. And the same thing with nitrates, and there’s certainly some nitrates naturally part of saline systems, but the bigger issue is that we have a bad habit of trying to farm these areas that are not productive. So we’ll apply nitrogen to them every year in the hopes that they might not be saline this year. And often there’s an accumulation of nitrates and other fertilizers in these areas. So use soil samples as a first step in managing and then be realistic, be realistic in terms of what you can grow there, what the yield potential is in those areas, and manage it accordingly. And sometimes we just have to admit that this is not farmland. It’s so saline that we can’t really grow crops there. So my final usual thought with this sort of thing is take all that money that you’re spending on these marginal saline soils and spend it where you have really good soils, where you can really make significant money per acre. Make better use of your farm expenditures.
Mike Howell (25:17):
Alan, anything to add on how we can manage a problem?
Dr. Alan Blaylock (25:20):
Yeah, going to more of what Lyle is talking about, one of your first things to start with is the soil test, and this soil test will identify your basic salinity level. From there, you can look at your crop options and say, “Which crops will be tolerant of this?” And you may be able to accept some moderate level of yield reduction, if the salts are not too severe, but you can look up the tolerance of almost any crop that you might want to grow, and you can say, “What am I limited to? What crops will this soil allow me to grow?” If salts are low, you have lots of choices. If salts are high, your choices become significantly narrow. I wanted to make a comment, specifically towards these forage crops, because there are some forage crops that are not very salt tolerant, like our legumes tend to be less salt tolerant.
(26:05):
Alfalfa is a highly productive forage, but its salinity tolerance is rather low. Most of the really salt tolerant crops are grasses, and they can do very well. But you can look up the salinity tolerance of each of those grasses, and there are tables that will show you an approximate yield reduction to be expected at a given level of salinity. If you look at the table and you have a 10% yield reduction at a certain level of salinity, you say, “Well, I’m willing to accept that, so I can grow that crop there.” But you might not be willing to accept a 50% reduction, so you go to something that is more tolerant. So that’s one of the things you can do in our irrigated areas. Then there are other practices that we can use. One of those is called maintaining a leaching fraction. If you’re able to irrigate and you’re able to control that water table with leaching of water, then we can calculate, for a specific soil and salt load, the amount of excess water we need to apply to maintain downward movement of those salts, and that’s what we call the leaching fraction.
(27:03):
You may need to apply 10% or 15% more water than would normally be required just to maintain downward movement. That could be a valuable practice. If you have the ability to irrigate, you can control the water table, you can calculate that leaching fraction. Then there are also some things we can do with planting configurations, and the way we shape the surface of the soil. Because the salts are going to tend to accumulate where the wetting front is, and maybe we can ridge that soil and plant the seed on the side of that ridge. The salts are going to accumulate at the top, but maybe we can plant on the side of the ridge away from that maximum salt load. So there are some things we can do with that to enhance germination of some of these more sensitive crops, that once you get established may be more tolerant. There are a variety of practices we can use. Many of them involve, where possible, physical remediation of the soil, like I mentioned earlier, many of them involve choosing a different crop, but starting with the soil test to identify what the proper practice is.
(28:01):
Now I should note another very important principle. When we get that soil test back, we start classifying that soil. Is it saline? Is it sodic? Is it a combination of high salts and high sodium? Because the remediation practices that we use could make a bad problem worse if we don’t do them in the right order. For example, a saline sodic soil has better physical properties than just the sodic soil. The high salt load tends to keep the soil flocculated more. If we start to leach those salts out, we create a sodic soil, which is more difficult to deal with. It’s important to know the exact nature of our salt problem before we embark on a series of remediation practices. There’s a great deal of information on this topic. There are lots of guides that can be looked up and follow those recommendations, but again, the soil test is the starting point. We may then move to physical remediation, crop choices, irrigation practices, and some of these kinds of solutions.
Mike Howell (28:56):
The Dirt is your place for the down and dirty agronomic science you need to grow, and now it’s an option for earning CEU credits. Visit eKonomics and click the Agronomics tab. There you’ll be able to review past episodes with credit opportunities. Credits are waiting at nutrien-eKonomics with a K.com. Well, guys, I really appreciate you taking time out of your day today to help us go through this soil salinity situation and learn more about it. Listeners, we hope you’ve gotten something out of this and learned how to manage the situation on your farm. Before we go, I want to ask our guests if they have any additional comments or anything else we need to talk about before we go. Lyle, any closing comments?
Lyle Cowell (29:38):
Well, I think the most important thing, when comes to salinity, is to be realistic on your farm. And we often talk about the four R’s of fertilizer management, and one of the most important is right rate of fertilizer, and soil salinity systems, saline systems, drive right rate for a lot of reasons. One, because of there’s simply the reduced yield, and so you have to adjust your fertilizer rates based on yield potential. And also saline systems, as I mentioned, will drive the fertility of your soil. They’re often lovely soils, they’re just too high in salts. And the primary salts are going to be some of those nutrient salts such as sulfates. So those two aspects, the supply of nutrients from the soil, as well as the demand from the crop that is affected by salinity, those will affect the right rate of fertilizer. And I think that’s the most important message that a farmer should consider when managing these soils.
Mike Howell (30:30):
Alan, what about you? Any closing thoughts for our listeners?
Dr. Alan Blaylock (30:33):
Yeah, I want to make a couple of comments and maybe if we have time tell a little story. One of the things, obviously, is to properly understand the problem, the source of the salts, the physical nature of the soil, your water table. That will tell us a lot about what we are able to do. And like Lyle says, being realistic because some of these problems are extremely difficult, if not impossible to fix. If we have an ongoing source of those salts, and we can’t really do anything about that, well then our options are quite limited. I want to tell a little bit of a story about our own family farm back in Eastern Oregon, where we had a sodium accumulation. It was of geologic origin. In other words, it was deposited there when the soil was being formed somehow, some way, I don’t know the source of that sodium originally.
(31:19):
But in the subsoil, we had this sodic layer that really impaired our ability to get water into the soils, an irrigated farm. And that sodium really was restricting water infiltration, our ability to water into the root zone. Tough to manage, and plus we had a lot of crusting. Underneath that sodic layer of geologic origin was a calcium rich layer. This was not an ongoing source of the sodium. It was there of geologic deposit. This was back in the 1960s. We had that farm deep plowed. Now, a lot of farmers, when they hear deep plowing, they think, “Oh, you’re plowing 12, 15 inches deep.” We’re talking 36 to 40 inches deep. Getting down into that calcium rich subsoil, parent material, underneath the sodium layer. We turned that calcium layer up, mixed it with the sodium layer. The calcium was then allowed to displace that sodium over time. Then that was, in this case, a permanent fix to that salt problem.
(32:14):
We were able to get rid of that sodium because we weren’t having new sources of sodium coming in, and it really changed the entire physical nature of our soils on the farm, and increased productivity and our ability to irrigate more uniformly and more efficiently. So understanding the nature of the problem. What is the source of the salts? What are the physical limitations that you have in your field? And what can you do with those limitations? In our case, we had the ability to correct that. Sometimes you don’t have that ability, and then you have to go to some of these other options we’ve discussed here today. Understanding the nature of the problem, understanding what your options are with that problem, and the proper steps to take for each type of problem.
Mike Howell (32:54):
Okay, well, once again, we appreciate you taking time to visit with us today. Listeners, I hope you enjoyed the first segment of today’s show. If you did, please take a minute and give us a rating on your favorite podcast channel or app, and give us some feedback as well. We want to hear from you to help make the show even better, and don’t keep it to yourself. Please share these episodes with co-workers, family, friends, anyone you think may benefit from the information we’re sharing here. Don’t forget to visit our website, nutrien-eKonomics with a k.com, to help find the latest crop nutrition news and research information, as well as market updates, a growing degree day calculator, a nutrient use calculator, a rainfall tracker, and much, much more.
(33:38):
It’s all at nutrien-eKonomics with a k.com. Most episodes of the Dirt are now available for CCA credits. Visit our website and click on the Agronomics tab to find these CCA credit opportunities. And if you have a question you can ask one of our agronomy team members. Simply ask your question and one of us will get back with you. Thanks for listening. Now, segment two of the Dirt. Well listeners, welcome back to segment two today, and we’re going to continue our spotlight of research stations across North America. Today to help us do that. We’ve got Dr. Jason White with us, Dr. White, if you would introduce yourself to our listeners and tell us what you do.
Dr. Jason White (34:20):
Well, thanks very much for the invitation to speak today. As noted, my name’s Jason White. I’m the director of the Connecticut Agricultural Experiment Station, or CAS, as we call it, C-A-S. We’re the oldest experiment station in the United States. We were founded in 1875. We’re the one agricultural experiment station in the country that is not part of a university system, and the reason for that is the original state law that was written in 1875 actually said we had to be independent. So every other ag experiment station that formed in the US, and every state has one, was incorporated into the land grant University of that state. But because of the way we were structured in the beginning, we are an independent state agency. So my PhD is from Cornell University, Environmental Toxicology. I actually started at the experiment station as a postdoc in 1997 and worked my way up through the ranks since then, and have a large research program on nanotechnology and agriculture, which I think we’ll talk a little bit about today, but also happy to entertain more broad questions on the experiment station in general.
Mike Howell (35:20):
Okay. Well, we sure appreciate you joining us today, Dr. White. Thinking back, we’ve talked about a lot of experiment stations and how they were all originated through the land grant system, the Hatch Act and the Morrill Act, and all of those acts that we talked about in season two. But this experiment station, if I remember right, was actually set up before those acts took place. Is that right?
Dr. Jason White (35:39):
That’s correct. The history here is that there was a Yale University chemistry professor who was named Samuel Johnson, and he traveled to Germany and the UK in the 1760s and 1770s. And in Europe, at the time, there was an agricultural experiment station system, which is a system where technically trained scientists, their job is to interact directly with farmers, with growers. He thought that was a great idea. So he came back and petitioned the Connecticut State Legislature to set up this type of system in the United States, an agricultural experimentation system. And the state statute for our founding was passed in 1875, and the initial two-year budget for our institution was 2,500 US dollars, and it employed two people. And we were originally housed on the campus of Wesleyan University for two years, and then we expanded, and Wesleyan needed classroom space, so they kicked us out. We spent five years on Yale University’s campus, in their Sheffield School of Science, but then in 1882 moved to our current location in New Haven, where we still operate.
Mike Howell (36:43):
Okay. Well, tell us a little bit about the research that’s going on there at the experiment station. What all do y’all dive off into?
Dr. Jason White (36:49):
I think one of the unique things about our experiment station, obviously we have a large focus on agriculture. That’s in our name, that was part of our founding, but we also have large programs on food safety as well as public health and the environment. So our total full-time permanent staff is around a hundred people, 52 of which are PhD scientists, who may as well be on a university campus. Most of them, vast majority of their job is to do research. So minus the teaching component. It’s research in those four broad areas. At any given time, we’ll have another 20 or 25 postdoctoral associates or Fulbright scholars or visiting PhD students helping us do our research. The agricultural component, a lot of it is driven by plant disease, and that’s where a lot of our nanotechnology work falls in. But we also have a large program on vector borne diseases, tick and mosquito borne diseases.
(37:38):
We’re a CDC center of excellence for that work. That’s a $10 million grant that just got reauthorized for another five years with Cornell University in Columbia. We also do a lot of food safety, surveillance and research. We receive about $600,000 a year from the US Food and Drug Administration for that type of work. And then, as I mentioned, environmental science. We have scientists working on things like PFAS and microplastics, fate and effects in the environment, those types of things. All of those programs do have a link to agriculture. Some of them are a little more tenuous than others, but I always argue that I don’t think you could find another institution, of our size, that does such a wide array of high impact scientific research in such a small place.
Mike Howell (38:20):
Well, we definitely appreciate the work that’s coming out of your institution. I know it’s definitely benefiting the growers there in Connecticut as well as across the country. Dr. White. I know you specialize in the nanotechnology, and that’s something that’s just coming to light, at least for me. I’m still learning about that. So I’m willing to bet that most of our listeners have never heard of nanotechnology or really don’t know a lot about it. So if you would, tell us a little bit about the nanotechnology and what’s involved in that.
Dr. Jason White (38:46):
Sure. So actually I was in that same situation about 2008 or 2009. As I mentioned, my PhD was in environmental toxicology, and I was working on soil remediation at the time, but then I started hearing about these materials called engineered nanomaterials. The concept behind nanotechnology is that when you have a material that is very, very small, in the nanometer size, so that’s a billionth of a nanometer, that material actually behaves differently. So whether it’s copper, sulfur, or iron or some other material, at the nano scale because of quantum effects and surface area to volume ratio, details we don’t need to go into. But the important part is fundamentally those materials behave differently chemically, physically, biologically. Nanotechnology seeks to take advantage of that difference in behavior. And nanotechnology has moved into just about every sector of our life. Our cell phones are full of nanotechnology, communications, medicine, but what became of interest, a number of years ago, was what would happen if these nanomaterials started making it into agricultural systems.
(39:45):
So as I mentioned, I’m a toxicologist. So when I started hearing about people putting nanomaterials either in pesticides and fertilizers, or just nanomaterials in biosolids, making it into farm fields, I just assumed nanomaterials were the next emerging contaminant. They were the next DDT or PCB or PFAS. We at the experiment station actually set up a program looking at the negative effects of nanomaterials in agricultural systems, a straight toxicology research program. We published our first paper in 2009, but what we noticed, and what the scientific community noticed over a number of years, is that under certain circumstances, not only are these nanomaterials not toxic, but they’re actually beneficial. They can enhance plant growth, they can enhance nitrogen fixation, they can enhance photosynthesis. They can be used to control and manage diseases. We transitioned to having two separate programs, one looking at the toxicity and safety of these materials.
(40:38):
But then the second program, which has really just taken off, both at our institution and in the scientific community in general, is looking at how we can safely and sustainably use nanoscale materials to increase food production. The motivation being we know we’ve got a rapidly increasing population. We know we’ve got climate change, which is making agriculture more difficult. We need to come up with some novel ways to increase food production, to address the food insecurity issues we have and that are going to get worse. So that’s kind of how we framed it. I think our approach is unique because it’s got these parallel tracks which are not really parallel, they’re completely overlapping. If we can’t develop a safe and sustainable way to use nanotechnology to increase agriculture, then we shouldn’t be doing it. It’s got to be safe and sustainable. It’s got to work.
Mike Howell (41:22):
That’s exactly right, and that’s something we talk about a lot on the program, is sustainability and safety, and we’ve got to make sure that whatever products we’re using are going to be both safe and sustainable. Dr. White, we really appreciate you enlightening us a little bit on your center there. Is there any closing comments you want to leave our listeners with?
Dr. Jason White (41:39):
I’d just like to say that I think this area of novel ways to increase food production is something that we need to work on. A lot of us need to be addressing this problem. Nanotechnology is one solution. It is certainly not the only solution. I think we’re going to need a lot of tools in our toolbox to address this issue of food insecurity, which has already been a problem, and is certainly going to be one that gets worse. And we here at the experiment station, think nanotechnology can be a significant part of the solution.
Mike Howell (42:04):
Well, listeners, we appreciate you tuning in. As always, you can check out our website. That’s nutrien-ekonomics with a K.com for more information. And until next time, this has been Mike Howell with the Dirt.
