Episode 11: How to meet changing water demands in a growing population

Episode 11: How to meet changing water demands in a growing population

Dr. Neil Hansen, BYU professor of environmental science, discusses water conservation, the latest research on getting more crop per drop, exciting applications of remote sensing, and the challenges we face trying to meet changing water demands in a growing population.


Neil Hansen, PhD, is an environmental science professor at Brigham Young University. Learn more about Dr. Neil Hansen:

Neil’s curriculum vitae and publications



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Hello everybody, and welcome to We Measure the World, a podcast produced by scientists, for scientists.

One funny story I’ll tell you, I mean, Ryan Christiansen our hardcore operator’s awesome. He loves the science as much as we do. And he likes it well enough that when we come up to work, he’ll let us borrow some golf carts from his golf course to go out into the field to collect our soil samples. One day, we were out there with a team of students. We collected 100 soil samples, measured soil water content down to four feet. And on the same day, one of my other students flew a drone that he got a great imagery, and it’s a bare field that hadn’t been planted yet. It wasn’t till we got home and started looking at the drone imagery. We saw all these circular crazy golf course golf cart paths that these students had just been having a blast on. Running these golf carts all over this 50 acre field. I was not paying attention, I guess I probably wouldn’t call them out on it. But the aerial imagery revealed they’re, you know, having a little fun out there.

That’s just a small taste of what we have in store for you today. We Measure the World explores interesting environmental research trends, how scientists are solving research issues, and what tools are helping them better understand measurements across the entire soil plant atmosphere continuum. To stay current on applied Environmental Research measurement methods and thanks for joining us. Today’s guest is Dr. Neil Hansen, Professor of Environmental Science at Brigham Young University. His research and teaching focus on water use and conservation in agricultural and natural systems. And his work includes areas such as dryland and limited irrigation agro ecosystems, and land management for water quality protection. He has published his work in several peer reviewed journals, including the Journal of Environmental Quality, and Soil Science Society of America Journal. Today, he’s here to talk to us about some of his many interesting research projects. So welcome, Neil.

Hey, thanks for including me, this will be fun.

Just to let us get to know you a little bit, how did you decide to become an environmental scientist? So yeah, what peaked your interest in that subject?

Yeah, great question. And, you know, it’s interesting to look backwards in your life and look at those kinds of pivotal moments that you didn’t recognize at the time would be really influential in decisions you make. As a young man, my grandfather was a cattle rancher in arid part of the state of Utah here in the United States. And my job as a young man was to walk along the perimeter fence of this mountain range land as pasture and repair the fence. And as a young man, it was just overwhelmingly incredible to see how a natural environment on one side of that fence differed in the way it looked from the more managed environment on the inside of that fence. Now, this was a mountain pasture, but I know now that he was doing things like herbicide applications from an airplane, aerial seeding. And the changes in that ecosystem was so dramatic, right to the fence line. It really just peaked an interest in me and how do humans manage the natural resources that we have? And how does that management, you know, alter the way nature works, and that kind of was a pivotal moment for me that I pursued throughout my education. My education took a twist towards agricultural scientists. I had several influential scientists that I knew in agriculture, studied soil science. And then, at one point in my career in my graduate studies at the University of Minnesota, that theme of, kind of, managed and natural ecosystems came back to play for me. We started looking at tillage practices, movement of nutrients in the landscape. Minnesota is known as the land of 10,000 Lakes, which is an underestimate. It’s a glacial landscape with, you know, lots of natural lakes, they play an important part of the economy for recreation and fishing. They’re all bounded by agricultural lands. And those two economic interests were really struggling to coexist. The agricultural impacts were negatively affecting the water quality and the fisheries and environment was kind of at odds with agriculture. And I had the chance for almost a decade to work in the middle there. How do we coexist? How do we manage our landscapes in a way that can can benefit both of those groups? And so it’s kind of a long story, but just some really interesting opportunities in my life that led me towards that interest of environmental science and managed and natural ecosystems.

I think that’s a theme that we’ve seen so far, even just in the several episodes that we’ve recorded, trying to find that balance between those that might have differing opinions on land management, like what to do with the land, what to do with these lakes, what to do with this ecosystem.

Yeah, that goes back into the basic philosophies of a conservation ethic versus a preservation ethic. And the idea of conservation ethic is that you’re trying to utilize landscapes and resources to meet needs and economic growth, and conserve those resources versus a preservation ethic that’s more of a hands off, you know, let nature be what it is on its own. And yeah, those have constantly been the source of a lot of dialogue.

Yeah. So I’m sure we’ll get into more of that as we go along and talking about your various research projects here. Let’s start off with your project that you did with farm water use in eastern Colorado. Yeah, can you just start off introduce us to that project? And what was the problem, I guess, that you were trying to solve there?

Really interesting and ongoing challenge. And yeah, this was focused in Colorado, but it’s really a global issue. And that is the competition for a limited water supply, and a lot of places in the world and Colorado at the time, urban growth was demanding more water for municipal use, and for homeowners, and the development of new water supplies, is really not a possibility anymore, all the available water is claimed and utilized. And so to make water available for those urban areas, they looked at the older water right holders, typically agricultural irrigators. They’re in Colorado, the irrigation is out on the eastern plains of the state, whereas the population centers at the what they call the Front Range, they’re at the base of the Rocky Mountains. So there was what they refer to as buy and dry, people would buy agricultural land with the intent of taking the water rights associated with that land, repurposing it to urban use, and then leave that agricultural land dry. So that buy and dry became quite a contentious issue in the state. And it still is, in a lot of ways. For the rural areas that depend on agriculture for their economy, that buy and dry was really devastating to the rural economy. So, that’s what led to this really interesting project that I had a chance to be a part of. One of the municipal areas that needed water was an area called Parker Water, it’s a suburb of Denver. Parker, really, was interested in trying to get the water in a way that was more sustainable, in a way, more supportive of those rural areas. They did purchase quite a bit of land on the eastern plains. But then they went to the landowners, the former landowners, they leased some of the land back. And they came to me. I was working at the University at the time and several others on our team and said, can we work together to find a model where we can take some of the water but keep these farmers viable? Keep their profit, you know, coming and keep the the economy going? So can we find a model that meets everybody’s needs? I had been working mostly at that time, in support of dryland farmers without irrigation, and you’d often hear a dryland farmer say, if I only had one rainfall in the second week of August, I could have made it. And that really weighed on my mind and like if these irrigation systems there they want to take some water away, move it to the city, can you keep enough water behind to give it those critical irrigations during key growth stages of the crop and make that an economically viable system? So that’s what we set out to do. We worked with a large group of local farmers. We asked them, hey, if you wanted to cut your water use in half or in some cases, we had a quota. We said, you know, no more than 10 inches of applied irrigation. It’s a little less than half of what you’re used to doing. What would you do? And we got a list of 30 different ideas or more, and then we put them out in a research trial. This was a multi year trial. It included crop rotations, irrigation practices, with and without fallowing of landscapes. And it was fun. We worked with growers, we worked with the cities, we have some of the funnest things. We’re walking through those research plots with municipal water suppliers, water attorneys, farmers, and just having a conversation about the challenges that we’re facing about meeting changing water demands in the world. So yeah, really cool project. And kind of one of the key outcomes was that there were opportunities. There were, among those 30, there were eight or ten really good options that involved maybe different crops, different irrigation strategies, different rotations, that were economically viable, and significantly reduce the water use.

When we’re talking about dryland farming, there’s a lot of tradition that goes into what they do. It’s multiple lifetimes and generations of experience. Were there things that you learned, I guess, from both sides? What did they learn from you? And what did you learn from them?

One grower that we were working with was a producer of confection sunflower seeds. These are sunflower seeds that you buy, and they’re salty, and you chew on them, they’re delicious. That producer was pretty influential in helping us develop one of our strategies that we tested, and showed us that sunflower was really flexible in how it would respond to irrigation. We put his test recommendations to the trial. And the basic idea was, let that sunflower kind of experience some water stress early in its growth, but when it’s starting to develop the flower, give it plenty of water. And this was almost laughable that we would get these three foot tall sunflower plants with a great big sunflower head on it full of seeds. The ones that we had been irrigating in a more, I guess, traditional way, or what we thought you would do, you know, irrigating throughout the growth cycle, they were tall, and they had little tiny heads on them. And so it really showed that, you know, if you know, the biology of the plant you’re working with and the crop and its sensitivity to water, you can get more crop per drop, right? That was kind of our theme is more crop per drop. And that was a really telling story for us. Now, a lot of growers out there weren’t growing sunflower, but that principle still held. Now, on the flip side, I want to say that one of the most interesting challenges that we faced was not an irrigation challenge or a plant biology challenge, but it was policy. The state of Colorado that’s tasked with overseeing these water transfers, if you move water from ag to urban, the basic policy was that they wanted to be able to drive by in a pickup and see that that sprinkler was parked and turned off and the padlock on the pump. And these a lot of these systems that we were proposing didn’t have that criteria. They were they were irrigating a couple of times during the year or they had an irrigated crop in a rotation with a dryland crop. And so this really kind of pushed the policy side to say, hey, how do we make sure that it’s working because you can’t transfer the water and use it? Or it’s not gonna work. And so that was one of the challenges that we had to work with is how can you monitor and document and show that the water consumption is what you said it would be?

In several locales, especially within the western United States where you’ve talked about water rights, and that it’s kind of a use it or lose it type of situation, from year to year. Is that the same kind of situation that you’re dealing with there in eastern Colorado?

Yeah, absolutely. What they refer to as the prior appropriations doctrine. Water rights are dependent on a beneficial use, that that water has been put to and the history of how it’s been used. And so yeah, that mentality of use it or lose it is prevalent, and it’s a challenge. But state governments, Colorado is a great example of looking at alternative approaches to water banking, or, you know, making it possible for farmers to conserve water and benefit from it. And the idea of having a farmer, an irrigator, in kind of a relationship with a municipal water user is really cool because the municipal water user has the potential to pay up front for the water, potentially giving the farmer some of those operation costs that a farmer often needs you know, you got to buy your for fertilizer and your seed. And before you get the money for that investment, if you can get that check and avoid having to take a big loan from the bank, because of the water arrangement with the municipality, that really adds some stability to the production system that’s really powerful. So, again, I think our project was instrumental in getting the irrigators and the policymakers and the water attorneys all talking to each other, and they came up with approaches that could work.

A lot of times science and research, they can divide individuals or groups, right? I think this is a good example of about how your research and science in general, especially in this case, with environmental science, can actually bring groups together and begin a fruitful discussion to move forward.

We definitely saw that and these were groups that did have a lot of tension in them. Those first couple of meetings, the people from the urban areas were out on the farm, and before you knew it, the farmers were feeling like that they were being targeted, and so they start shooting that No, you guys use it wastewater on golf courses, and the farmers would shoot back and forth with them. But inevitably, after spending a couple of hours together, the conversations turned to much more productive, helpful understanding each other kind of, and yeah, the science was sitting in the middle of that. And the science hopefully provides some solid answers. But I think it also provided a framework for those discussions.

That’s great. Were there any other interesting results that came out from that project?

Well, there’s one it’s the water management is super complicated. If you, if you see, like, take a ditch company, you know, a big group of farmers, if they were to adopt some of these water conserving irrigation practices that we developed, they’re changing the timing of water diversions out of the rivers and canals and into the farm. The quantities, the timing, the amounts, the big challenge that was something a lot of people don’t think about is how that would affect the return flow back to the river system. A lot of those irrigation systems are inefficient. If they’re doing flood irrigation, for example, some of that water makes its way back through the aquifer and into the river system. Somebody downstream has a water right to that return flow. And so when you start altering the irrigation practices on pretty large areas, you have to, you’re required by law and these systems to mimic the historical return flow patterns. So not only did these farmers that were entering into these water trading agreements have to track the application of water. They had to document how the return flow was being impacted. And some really interesting things were developed, including some what they call returns, blanking on the name of it right now. But these were storage ponds, essentially, you take some of that water that you’re no longer putting through your sprinkler and stick it into a retention pond, and let that slowly infiltrate to the groundwater to mimic the historic return flows that the water rights system depends on.

Interesting. I assume that there’s probably lots of other ways around that. But that’s really interesting.

Other constructed wetland type area,

right? Yeah.

And what was cool is they had other benefits, right? I mean, they were benefiting wildlife habitat. So in this case, you were trying to solve one challenge. And you end up having solutions to other problems, habitat, riparian area kind of thing. So

right, and especially throughout the world, we’re trying to get groups involved in green architecture and city planning. So being able to mimic a wetland in this way benefits not only just right there in that area, but elsewhere. Would they bring in different materials? Was it for materials? Or would they take the actual natural soils and layer them as they would in the normal environment?

Yeah, some of both. I mean, some of these wetlands had historically been in place, and really the way that water had been diverted and moved away from them had left them dry for many years. So in a lot of ways you could use former wetlands and kind of recreate them without a lot of manipulation. But there were examples to where more earth moving was happening and creating those really, really pretty neat systems, but they do illustrate the complexity of these water systems that water is managed and moved and quantified and manipulated in these river systems in a really big way.

All right, so let’s move on to another project of yours, the BYU turf farm. Yeah, can you tell us a little bit about that project, how it started, how it came to be and everything?

When I came to BYU, I really didn’t have any experience with turf grass. My colleague, Dr. Brian Hopkins is kind of the one that leaves out on the scientists, but on these projects on turf, but my expertise and interest in irrigation improvements, smart irrigation systems, using sensors to improve irrigation, mostly I’d done that in an agricultural setting just seemed like a good collaboration to jump in. And Brian and I, we teamed up with Colin Campbell at METER. We started kind of simple, actually, we had some existing turf plots that we instrumented with volumetric water content sensors and water potential sensors. And for quite a little while, we just tracked what was happening with the way they were being irrigated. It didn’t take us very long to figure out that the irrigation was excessive. We worked with our local grounds managers here and kind of work towards creating a system that looked at the sensors, used sensor information. And at the same time, the health of the turf improved. And it again, it just triggered us that, hey, there’s things that we could need to be doing here, because we live in the middle of a pretty big urban area with a lot of irrigated turf grass. So that first little venture into this cooperative project that developed led us to control of irrigation on replicated small plots of turf grass that we can manipulate and manage in different ways, all with the goal of trying to figure out what can we do, from a management standpoint, to maintain the turf with, you know, the least consumption of water possible, fertilizer, and water? It turns out to be a really interesting story. When you have the right amount of nitrogen, things work pretty well. But what often happens in a, especially in a homeowner setting is if a little is good, a lot’s a lot better, right. And so we see a lot of grass, it gets quite an excess of nitrogen fertilizer. And for the homeowner, maybe the outcome of hey, my grass is greener than yours, and it greened up earlier in the spring. And it’s, you know, that can maybe reword that, that nitrogen fertilizer, but what we’ve learned is when you put a lot of nitrogen on, you get a lot of above ground growth, it drives water use up, and then what you don’t see is below ground, it’s reducing the depth of root growth. And when that happens, you created a scenario where it’s hard to keep up with the irrigation in a hot dry summer in an arid place. And so you start putting more and more water on, you’re only really feeding a shallow four or five inch root zone. And the other thing that happens when you do that is you’re pushing the nitrogen fertilizer out of the root zone, which means you need more. So you get into this negative spiral in those two management, input management where you’re driving water use up, you’re making it harder to irrigate. So we set out to, it’s not a super complicated study, but to try to come up with more of an optimized combination of irrigation quantity, nitrogen fertilizer rates and timings, to, you know, keep turf grasses a viable landscape option in an arid place, but minimize the water consumption.

You’d mentioned earlier that you’re looking at water content, water potential. Were there other measurements or what else were you looking at there in that study?

Yeah, that’s been fun. In addition to those sensors in the ground, we have been exploring the use of remote sensing to trigger you know, to tell us when do we need a water and those kinds of things. The two main ones that we’ve evolved to use quite a bit is the canopy temperature. So we use an infrared thermometer targeted at the surface of the grass. It’s a fairly well known phenomenon when if a plant starts to experience drought stress that closes the stomates on the leaf, it stops transpiring water and the temperature will respond, that surface temperature goes up because it’s lost the cooling effect. And so if you can detect that, essentially, you’re letting the grass say, Hey, I’m thirsty. Put some water on, and that’s been pretty effective. And then the other sensor, the end DVI, that’s a light reflectance sensor that essentially looking at turf health and color. That is not very valuable actually on irrigation management. But it does help you understand and manage the nitrogen fertilizer inputs better. So the combination of those two remote sensors is pretty powerful. And we’ve been using those together with the soil sensors to understand the system, but potentially in a, in a managed system where it’s not a science project, you know, you may be able to do some things with one or the other. You don’t need to have the whole suite,

you talked about that whole suite, and being able to optimize yea your fertilizer, your water. Is there an optimization then of the number of measurements or types of measurements that that you want it to take there as well?

Well, the types of measurements is a fairly easy question for me. I have really learned to love using a pair of sensors, one looking at water content, and one looking at water potential, side by side, same depth. At least initially, for a new new sight. When I look at those together, I am able to understand the water retention properties of the soil along with how the plant is responding to it. So you know, those are those are two sensors I’d like to use together. But you also asked me about you know how many sensors and that’s actually one of the biggest challenges that we’re still trying to figure out how to solve. These urban landscapes have a lot of inherent spatial variation, and sensors. One of the weaknesses of a sensor right is that it’s measuring a spot or a point. So a water content sensor can tell you what’s happening in that spot that you have to be able to use some kind of other information to extrapolate about how that point relates to all the points in a field. We’ve taken our project that we started in kind of these replicated plots, and we are now partnering with the sports turf managers on our university campus. And this has been really fun and really eye opening. And we’ve got sensors on our University football field, which is a pretty, you know, high visibility location for us. It’s been a lot of fun. But in that environment, the manager just says, Hey, I can’t have dry spots, you know this, this has to be pristine when 60,000 people come to watch a sporting event. So we’re working with him to try and figure out how do we take what we’re learning from these sensors, and translate it to an entire management for his field? And, that’s probably the biggest challenge that we’re still trying to figure out. And there, maybe you do have to couple it with some remote sensing devices. But I think that you never get rid of the need for you know, John, he’s the sports turf manager, we need his experience and expertise. And I think the human experience together with the sensors can lead to some smarter irrigation decisions.

I think that segues into my next question is, could you speak to a little bit about, you know, smart irrigation? And how far that’s come?

Speaker 2 28:17
Well, yeah, the urban setting, there are amazing products available. The irrigation controllers that are there’s a kind of a different set of technology. Some of them use internet connections, getting information from local weather stations doing ET calculations, and recommending, you know, rates that adjust throughout the year. Others are capable of interfacing with sensors. So the idea of a smart controller is pretty powerful. I think that we’re pretty low on adoption of those technologies. So I’d say in that timeframe that you mentioned, and we’ve come a long ways on the science. Even the science of nozzle technology had sprinkler heads, being able to design a landscape that has water conservation in mind. There’s a lot of really great principles that have been developed. Still a lot of need, though for adoption. And again, when you get back to that kind of policy interface, how do you, how do you take these technologies and incentivize and educate people to put them to work? Now on the agricultural side, just really exciting things. There’s a development in again, nozzle tech, the engineering side of things, what do the nozzles look like? Pressure regulators huge, huge development and drip irrigation. And, there where you have an economic benefit to these adoption that the adoption is better. And clearly, we’ve seen a massive conversion of traditional flood or surface irrigation systems to sprinkler and drip irrigation. And technology, there’s still a lot of space to go for better improvement. Now, in both the urban and the agricultural settings, one of the greatest things that’s happening is just the use and application of remote sensing, being able to look at landscapes, look at agricultural fields and see when something’s gone wrong. Center pivot sprinklers are really fun to look at from, you know, if you’re looking from a satellite image or drone image, if there’s something wrong with a nozzle, or a sensor, or whatever, you tend to get these donuts around the field. Because those problems are traveling in a circle, right? And so just being able to monitor things and see things on a regular and routine basis, is a really great technology that’s improving water use efficiency.

So what are the next steps then for the BYU turf farm and for that project?

Yeah, like I mentioned, I think our biggest challenges at this point are for us, as scientists to learn how to work with the sports turf managers in a way that results in improvement and change that works for them. And that delivers a product that they’re happy with. I’m very happy with the information we’re getting from the sensors. And we are in the process, we sit down with them when they have time and show them what we see when we look at the sensor data, and then we listen to them. What do they see, that works or isn’t working. And so I think similar to what I described in eastern Colorado with the water exchange, I think there’s just a little period of time here where we’re trying to understand the user’s needs and the science and bring those together to create solutions.

Your talk of being slow to adopt some of these solutions, do you think some of that is that these new technologies and innovations are more cost prohibitive? The idea of smart homes was really big a few years back, it has seemed to have waned a little bit. But having you know, this, everything, the Internet of things and having your whole home connected. And it really only seemed that there were a few early adopters, and it kind of, kind of slowed a little bit. Do you see the same thing happening with the smart technology and smart ag and smart irrigation?

I sure do. Obviously, the rate of adoption is ultimately driven by the bottom line. And as you brought up, and if the cost of adopting technology is higher than the potential savings, adoption is going to be slow. But you got a couple of trends really driving right now. Water scarcity is pushing the cost of water up. Always, water costs are coupled with energy costs if you’re pumping water. So when energy prices go up, there’s a reason to save water too there. So you have costs driving higher. And you have, I think, improvements and the pricing of technology. So, to me, I think we’re really going to continue to see adoption in, I don’t know the pace of it, but I think it’s going to, it’s going to show its value, and continue to make a lot of sense for people too. I like what you said the internet of things, I think that that’s a part of the way we manage water in the future.

Elsewhere in Utah to your other ag related projects, they’re in that state. You know, as you’ve been trying to bridge the gap between you know, one size fits all irrigation method for field, how’s that going from moving from that towards a more variable rate irrigation system where the growers also are empowered and understand what’s going on and can apply the water themselves and what rates and what amounts and those kinds of things?

Yeah, so in an agricultural setting, this concept that you’re alluding to is referred to as VRI, variable rate irrigation. VRI is a concept that a single field can be irrigated, according to the site specific needs within the field. Now, a center pivot sprinkler is a beautiful piece of engineering technology to be able to apply a uniform rate of water. If you think about that big circle that’s going around the inner rings of that or just go on a short distance and this one’s out at the end are covering this huge distance. And yet the way the nozzles and the pressure regulators are combined, you’re getting a uniform application of water. That’s the way they’ve been designed. That’s a beautiful thing. But we’ve gotten to the point now where we realize the field is not uniform You’ve got variation in slope and topography and soil type and just the way the crop is growing in a given year. It’s really pushing it to the next level to say, Okay, let’s don’t go to uniform application, let’s go to site specific or VRI, variable rate irrigation. And that’s a project I’ve been involved in, that the companies that make the pivots have been developing this and have done some really amazing technology. We got started in this project with a farm cooperator. His name is Ryan Christiansen, and he farms near Grace, Idaho, actually, so we’re here in Utah, but we traveled to Idaho to do this work, because it’s so interesting for us. Ryan and his family actually bought one of these state of the art variable rate irrigation systems (VRI). I think they own one of the only center pivot irrigated golf courses on planet Earth. They irrigate a golf course. And they wanted to be able to irrigate the greens and the fairways and the out of bounds areas differently. So they bought the system, but they irrigate that whole golf course, and just half of the circle. Ryan’s a friend of ours, and he said, Hey, what should I do on the on the farm side of that circle? And we started working with Ryan, we’ve continued to work with him for almost seven years now. Trying to figure out how to best utilize that technology. And it’s been a really good and fun and eye opening project. One thing I can say is, there is no doubt that the crops he grows, winter wheat and potato. Both of those crops have variable needs that are significant within that same field. And it’s not a highly variable looking field, you’d look at it and not say, Oh, wow, it looks relatively uniform to the eye. But it’s not, there are variable water demands. And we’re learning how to identify those, and how to control the sprinkler. And he talks about technology and the Internet of Things. Ryan controls that sprinkler from his cell phone. He has a GPS map, he’s delineated that field into multiple zones that can be irrigated variable rates. And it’s been exciting, the science together with a cooperator and the technology and the sensors, we use sensors in those zones. We’ve been able to, you know, people hear these numbers and don’t say it doesn’t seem like much, but we cut his irrigation from an average of something like 12 inches to a little more than 10 inches. So you know, at 1.8 inches of irrigation reduction, doesn’t sound like much until you translate that into the gallons, that 1.8 inches is two and a half million gallons of water. And that’s real. And Ryan loves it. He’s since invested in another system on another one of his pivots. And he has plans to do more

What are the factors that go into the decision making process when it comes to variable rate irrigation? You know, you mentioned soil type, you know, the type of crop that they’re dealing with, I assume are water content, water potential, those kinds of things.

Yeah, exactly. That is, again, I’m not smart enough to be an engineer to figure out how to create the VRI system. But from a soil science perspective, what you’re asking is exactly what interests me is, how do you tell it what to do? And there are a variety of philosophies or some colleagues of mine around the world working on similar, you know, questions. So mine’s not the only answer. But we’ve decided that we want to use relatively permanent zones. Subdivide that field into relatively permanent zones, and then use sensors in those zones to tell the sprinkler how much to apply. So how do you create the zones? And what we’ve learned is, some of the most powerful variables are historic yield variation. This farmer and many these days have yield monitors on the combine, right? So it’s able to make a map of yield. So areas with higher or lower yield become part of the equation to create these zones. So historical yield, and then topographic variables like the relative elevation field parts of the field that are higher or lower, even if it’s subtle, even if it seems relatively subtle. That really drives the need to irrigate water, to apply irrigation in a different fashion. And then we’ve done some other we’ve done electrical conductivity mapping of those fields. We’ve done some geographic modeling, there’s a parameter called the topographic wetness index. But among all those variables, probably the two most powerful ones, is that historical yield and the topographical, the relative elevation. We validated those by measuring water content changes. Anyway, we do all those soil samples, not because we think any farmer would ever do it. But that’s how we validated the way to create the zones using those more simple to obtain variables, the yield maps and, and those things. So that’s what we do, we subdivide the field with spatial information, we put a pair of sensors in each of those zones. And then we track, we track the water retention properties and the change in water content over time. Every time the sprinkler comes on, we make a recommendation. And you’ll see one zones getting, you know, three quarters of an inch of water and another zones getting half an inch or a quarter on any given day. And then the water savings that I mentioned, that’s when you add all that up and compare it to what would you have done if it was a uniform irrigation, you’re saving water. And in some cases, the crop is healthier. I think particularly on the potatoes, you’re avoiding some excessively wet areas that make the potatoes prone to disease.

So do you feel that this type of situation is applicable then to any type of agriculture?

Certainly agriculture is going the way of precision right? This variable rate irrigation(VRI) is not the earliest thing that variable rate nutrient applications is much more mature and developed. And it’s to a point that it’s a relatively standard practice among large producers. So things are going towards variable rate, seeding rates, changing the population of seeding or and even in some cases, the hybrids or varieties that are being planted, technology to precisely apply pesticides or herbicides, rather than blanket applications everywhere. I see that these precision, spatially variable, temporally variable technologies are increasing in adoption as we go forward and paying off. They’re saving resources, they’re making the impact of agriculture on the environment less and making the production more efficient.

What were some of the specific benefits that Ryan Christiansen had seen? And how does that translate then to benefits that others might be able to see?

One of the things Ryan shares with me is having the sensors in the field gives him a sense of flexibility and security on it. Because he’s managing multiple pivots, multiple fields, on that same field, he’s managing a golf course and an agricultural field with the same pivot. Having those sensors gives him power to make informed decisions that can benefit not just the field where the sensors are, but other fields where he’s moving water. So I think, you know, that’s, not to be overlooked. The sense of security and peace of mind that he gains from having an assurance of what’s going on and whether he needs to irrigate today, or he can wait a couple days. So that’s something that translates to an urban setting, too. I mean, anybody that’s managing water, I think making informed decisions, leads to better decisions.

And with all of these benefits, how then can we help share or at least do a better job of sharing this information or this knowledge with other growers or others who might be interested in this?

There really shouldn’t be any reason that we’re not getting the word out on development. I appreciate you’re doing this podcast. I think that’s a great vehicle, social media. Our science, in some ways is a little bit crippled by our measure of success is a peer reviewed journal article. I mean, that drives what we do, and there’s good reason for that, right? I mean, that’s how we keep the trust in science and keep things at a high level of integrity. But the drawback to some of those things is they can be slow at times and maybe not accessible. A lot of the practitioners and users aren’t reading journal articles. And so it does be behoove us as scientists to make sure we’re communicating not just in the journal articles, but getting the word out. And in places where users can get it. At that farm and grace on the golf course, in the ag field, we had an outreach event this past year. It was organized by Utah State University Extension Service, and one of the colleagues that’s involved in this project. But it was just a phenomenal event. There were irrigation suppliers, farmers, educators, they were there. And I think, you know, the more that we get together and see things, we weren’t just the teachers there, we were there to learn. And a lot of the people are pointing out things in our study that maybe it didn’t work for them and thinks that, you know, hey, could you look at it this way? Could you measure this? So the more we get together in those kinds of settings, the better the science becomes, and the more useful it is.

So, I think that also really transitions well into this last subject we’d like to cover. Helping to mentor and develop the next generation of researchers and scientists, one of the great things that BYU does really well is being able to give research opportunities to undergraduates, and that doesn’t happen very often at research universities. And you’ve been finding success in working with students. You know, bringing them along, allowing them to give presentations to you mentioned, taking them to those research projects. They’re at Christiansen farms, even if they did drive golf carts all over the place. But really allowing them to take a proactive role in the research itself. So I’d just like to hear your thoughts on on that idea of of mentorship and developing, you know, that next generation of scientists and researchers?

Well, thanks for asking, it’s something that I care a lot about. And you’re right, BYU as an institution is committed to we use, we use the jargon here inspired learning, right? It’s kind of a two way phrase. If you get young people involved in research, they’re up, they’re encouraged and inspired, it really motivates and drives them. But the other side of things is they actually bring inspiration too. The learning becomes inspired because of them. I think a lot of young people, BYU is definitely this way, we don’t have a lot of people that come to this university that have much experience with agriculture or irrigation in an urban setting. But the fact that we are working with really cool technology with sensors, with drones, you know, it’s invigorating for them. And they’re tooled up to add to what we have. So in a lot of ways, in my work I’ve learned, I help students see the question, and then kind of get out of the way and let them find answers to the questions. And it’s been really fun. Yeah, sometimes they need a little more guidance than others. But in general, I found that they bring a lot of energy and a lot of creativity. And I think Ryan Christiansen would say the same thing. He’s, been a great mentor, the students that come up, I mean, he’ll take a little time. And while them with a great big farm equipment that he drives or whatever, you know, they’re seeing things they’ve never seen before. And then they’re bringing their innovation and their technology to address the questions that he has. So it really is it’s not, it’s not a service to the next generation, it’s a desperate need for all of us to engage them. It’s just been, for me, it’s a fortunate part of my job that I’ve been able to discover that. So

I know that that hits home for me, and many of us here at METER. And I can guarantee you that the vast majority of our audience, as well have had those kinds of relationships, either to be mentored or to mentor others. Anything else.

Well, this has been fun. I really, I love the concept of using technology. Since you know, as you guys said, measuring the world, as you guys call this, I just think water is one of these pressing global issues that technology can help us manage better. And I love being a part of a global community of scientists working on that. And we’re making good steps forward. As we’ve talked about, we need to continue to make sure we’re getting the science into the hands of people that can use it and decision makers can apply what we’re learning, but there’s a lot of progress to be made. And we need to make it kind of quickly because it’s an urgent, global issue.

There are many of those natural resources that we’re running out of, but human ingenuity is not one of those. So hopefully we can help improve things going forward here soon. All right. Our time is up for today. Thank you again, Dr. Neil Hanson, for taking time to share your research with us. And if any of you in the audience have any questions about this topic, or would like to hear more, feel free to contact us at metergroup.com. Or you can reach out to us on Twitter @meter_env. You can also view the full transcript from today in the podcast description. Stay safe, and we’ll see you next time on We Measure the World.

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