Articles, Blog

Managing Agricultural Drainage Water: The Current Webinar 8

August 13, 2019


Good afternoon, everyone. This is Rebecca Power, and I would like
to welcome you to to The Current, the North Central Region Water Network’s
speed networking webinar series. The purpose of the current is to increase your access to University Extension programming and research that
we hope will be useful to you in your own work. The format is three 10-minute presentations with
questions and discussion at the end. So we’re going to hear all of our presenters today, and then I
encourage you to submit questions via the chat box which I’ll say it a little bit more about in a minute. All the webinars that we’ve
done have been archived on the North Central Region Water Network website at northcentralwater.org, so those are available for you to review at your leisure. Our topic today is Managing Agricultural
Drainage, and thanks to Chris Hay from South
Dakota State University for organizing this session and for
being one of our speakers. You’ll also hear from Jane Frankenberger
from Purdue University and Richard Cooke from the University of
Illinois, and I will tell you more about them right
before they speak. This webinar is the eighth in our series, and I’ll just give a quick commercial for the ninth. That webinar will take place on June 17th at 2 p.m. Central, 3 p.m. Eastern, same time, and the topic of that webinar will be cover crops and will be- we’re being assisted by the Midwest Cover
Crop Council and Dr. Dean Baas from Michigan State University in putting together that session. Just a few tips for a smooth experience, I am going to back up here for a minute. For those of you that are speaking, we have those folks
on a headset with a microphone and if you end up speaking to ask a question using that headset and microphone for best results is often the best. Please submit your questions to
presenters via the chat box as I said earlier, and that’s typically in the
lower left hand corner of your screen will be monitoring those and collecting them and synthesizing those for the speakers at
the end of the session. If again we have the opportunity
for interaction depending on the number of participants that we have today please raise your hand. There’s a
hand icon again somewhere probably in the
left-hand part of your screen. So raise your hand and one of the moderators will call on you and then you’ll need to press the talk button, which should be further
up on the left-hand part of your screen with a little
microphone icon, and we will call on you. Okay, as I said these are today’s speakers: Jane Frankenberger from
Purdue University, Chris Hay from South Dakota State
University, and Richard Cooke from the University of Illinois. So let’s get into our introductions. Jane Frankenberger is a professor of agricultural and
biological engineering at Purdue where she focuses on water management
and water quality and drained agricultural watersheds. She
works with the drainage industry to improve water management practices and with conservation agency staff and
citizens to manage watershed more effectively through the Indiana Watershed Leadership Academy and other water
quality programs that she leads. Over her 19 years at Purdue, she has benefited greatly from interactions with other water specialists across the North
Central Region and is looking forward to working with
many people across the region in the new project she will be describing the
day. So what Jane has done here briefly one of the purposes of these webinars is to help extension educators, other university
folks, and our partners whether they be
from local conservation departments or federal agencies, state
agencies, farmers, environmental organizations, people that are interested in water
resource management, and learning more about the resources that they have access to across the North Central Region, and Jane is one of those resources. So, Jane, take it away. Okay, well, hello, everyone, and I’m pleased to present an overview of a new project that we have, and I’m
presenting this on behalf of quite a large team, the corps members of which are listed here at the bottom. I won’t take time to read them all now, but you can see that we represent most of the North Central Region plus North Carolina. I also want to
acknowledge funding from USDA NIFA through the water for agricultural program. The official title for the project is
shown at the top: “Managing Water for Increased
Resiliency of Drained Agricultural Landscapes”, but as we’ve talked through our ambitious
goals for the project we determined that a short statement of
what we hope to accomplish is transforming drainage, so it’s a huge goal, and we won’t get
there in five years, but we will lay a foundation which I’ll
talk about today. So tile drainage as most of you
will know is a very widely used practice on poorly drained soils, and it is used to increase crop yield in all locations and in some locations
actually is needed to make agricultural possible, but the widespread
use of drainage also leads to a widespread
concern which used to be increased nutrient
losses which to rivers and streams the
tile drainage causes. This is especially true for nitrate which we have been trying to address for
decades and more recently the the scale of phosphorus loading into tile drains has also become more widely understood. So now we really are talking about nutrients both nitrate and phosphorus. So these nutrient issues are important the national scale both
hypoxia in the Gulf of Mexico which is primarily in a nitrate concern
although also phosphorus and toxic algae in various lakes but most recently in 2015 the terrible situation in Lake Erie, in Toledo where 500,000 people were without drinking water for a few days, I think shook a lot of people up and really got
back to the need to really become serious about addressing
phosphorus and some portion, nobody knows for sure, but
maybe something like fifty percent goes through the tile drains. Our project also addresses a second issue
which is not directly related to nutrients which is that even in the relatively
humid Midwest crops often suffer from a lack of water, and this was driven home in the drought
of 2012, but water deficits occurred nearly every year, and in response irrigation has become
more widespread throughout the region even in places where irrigation has not
typically been used. Both of these issues, so the excess
nutrients that I talked about beginning and the
lack of water in summer, are expected to become worse through climate change as we expect warmer and wetter springs that will exacerbate the nutrient issues,
and drier summers are also expected which will exacerbate the crop water deficit. So what we’ve been thinking about in
this group of researchers and extension folks from across the region is the need
to retain drain water in the landscape to address
both of these issues. So the question is where can you retain
water in a typical field that looks like this? So we’ve thought of a few places. One practice is called drainage water management, and in this practice we actually retain the water in the
soil of the field, and I’m not going to go into it in
detail because I believe Chris Hay will be talking more about some of the research that’s going on. So
that’s one possibility retaining water in the soil. Another is to retain water in the buffers, and there’s a practice called saturated
buffers which has been gaining- it’s being researched across the region, so it retains water in the buffers, and
then the third practice which is much less common and hasn’t been studied as much
is what we’re calling drainage water recycling, it also has a few other it names, but the
idea here is we have a pond or a reservoir and does the subsurface drainage and also the surface runoff are actually captured in the reservoir and then pumped back onto the crop land to be used by the
crop later in the season. This is a great practice; it’s not new, there’s been research since the 1980’s that have addressed that. The image there is of the wetland reservoir sub irrigation systems that were put in in Ohio in the 2000’s, and
there’s been several papers that have published the crop benefits of those. There’s also been systems in Onterio, Iowa, Missouri, Illinois, and folks in Canada are trying to do this,
but those have been just one system, it really is not widespread at all, but if these practices- so we got 3
practices, if they’re not new, one would likely
say well what is new about this project? And although these
practices have been evaluated in various locations across
the region, what we’re going to do in this large new project is to try and
bring the results together for improved decision-making,
and the map here shows the research areas, the places where there are data, many of which have already been published but we’re going to put them in one large database in so
that much more synthesis and recommendations can come out of them. So that’s the big new effort that will be
starting all across the region. It’s a daunting
task but one of the reasons we think we can do it is there’s been another coordinated
agricultural project that’s been going on for a little more than four years now
called the Corn Systems Coordinated Agricultural Project or sustainable corn, and so some other the data sets are
already in that the database, and it’s taught us a lot
about how to get large datasets together, so we’re
excited about doing more with this. This is sort of a diagram of what we hope to do in this project. I am not sure I have a pointer here so I’ll just start on the left with Objective 2 which you see on
the bottom. So we got these 30 field research sites, out of those we’re going to do Objective
2. Oh, let’s see if I can do this. No. Objective 2 is synthesis, so we’ll be working on that though the database. Objective 3 has a lot of modeling to extend the findings and both of these
will also look at the economics because I didn’t mention that yet but
obviously the economic barriers are the major barriers to getting these
in place, so we’ll be seeing on how we can address those. Then out of that Objective 4 will be Tools for Decision-Making and
then Objective 5 and 6 are Extension and then
Education to graduate students and teachers, but what I want to end with is the Objective 1 that’s across the top in this image. Which is that one thing that’s critical to make this project successful is the network which we already have within
the project team itself. I showed the team on slide 1, but we have many
collaborators that I didn’t necessarily list here and stakeholders, and we’re looking to expand that even
further. So the expanding and strengthening of the network that could include all these sorts of people here is a goal of
the project, so from the top we’ve got farmers involved, the drainage industry,
researchers, the Natural Resources Conservation Service which makes
decisions about conservation practice incentives and cost-sharing and technical standards are critical, we have drainage contractors involved, the
US Fish and Wildlife Service, because some especially as these ponds we have aquatic ecology effects, nonprofit organizations like the nature
conservancy, and state agencies. So these are all
critical, and one of the ways they’re involved are through an advisory committee, so I
thought I would just put this up because I had this slide that shows some of the broad expertise that we have on the advisory committee for this
project, but more important is the you who are on the call might be
able to be part of this as well, so I thought that I would just um
say contact me with an email address. As of today we don’t
yet have a website. This is a very new project; we just had our
kick-off meeting a few weeks ago, but we will have a website and many
ways that we hope people will get involved. So that’s the goal, nothing short of actually transforming the way that we do drainage. Our sort of short term outcome is that by the end of the project producers will be able to access the
research-based information that they need so that they
can make informed decisions about retaining drainage water in the
landscape and that should lead to increased resiliency. A longer-term vision probably beyond the
scope of this project is that the process of designing and
implementing agricultural drainage will actually be transformed so that at
least, so that water retention in the landscape is at least considered every time a new
drainage system is put in. And so once again the nitrate and phosphorus losses that are having such a negative affect on our streams and
rivers will, the nitrate and phosphorus can go back onto the tile drain and – sorry back onto the crop field and actually be, although it still might come up through the tile, it can be eliminated from our rivers and streams. So Chris Hay is going to talk about one of those practices, and Richard Cooke will talk about another related practice, so that will
give you more information. Thanks so much. Great, thank you, Jane, and please remember questions for Jane or questions that are coming up about agricultural drainage more broadly
please put those in the chat box, and we will get to them after our third
speaker. Chris Hay is next. Dr. Chris Hay is an assistant
professor and extension water management engineer at the Department of
Agriculture and Biosystems Engineering at South Dakota State University. His research, teaching, and extension programs are focused in the areas of agriculture
hydrology and water management. Examples of his research includes studying the impacts of subsurface drainage on hydrology and water quality in transition from subhumid to semiarid climates, and impacts of drainage and cover crops on evapotranspiration. His extension programs focus primarily
on drainage, irrigation, and water quality, and he has
been recently leading a program to train NRCS staff in the North Central Region on drainage water management. Thanks,
Chris. Chris, maybe press your talk button? Hopefully, we can hear you then. Yep, got that would
help. Hi, good afternoon and thanks and as was mentioned I am going to be talking about a specific practice here called Managed or Controlled Drainage which is one of the practices involved in that new project that Jane mentioned. Again, this is not a new practice, but one that’s been around
for a little while so although there certainly still some
research questions associated with that there’s also a lot that we do know about
the practice come and what we’re talking about with
this practice then has using control structures to actually manage
the timing and amount of drainage that we let leave that drainage system. As it was being developed in North Carolina oftentimes that was done by actually managing the water level and the outlet ditch, but as it has transitioned here into the Midwest now most often that’s a control
structure actually placed in line with the drain pipes themselves. And a little bit of semantics here, when
the practice was being developed in North Carolina that practice was typically called and still is called controlled drainage. As it shifted and started being applied here in the Midwest now there’s some concerns about the term
control of drainage, and so drainage water management was really coined as the term for that practice, but also there’s been a kind of a shift where
drainage water management has also started to take on some other practices related to this specific practice, and so
sometimes that’s a little bit a source of confusion, but when I talk about controlled or drainage water management here I’m talking about the specific practice. And one of the things that was coined by Wayne Skaggs who’s one the preeminent drainage researchers here in the US was this idea of the golden rule of drainage, that basically we should drain
only what’s necessary to ensure traffic- ability and good crop production and not a drop more, and so drainage water management is one of those practices that fits right in with this golden rule of drainage by actually managing that drainage instead of just allowing drainage to occur anytime the water table rises. And the key concept behind that is when we look at patterns of
precipitation and evapo- transpiration, so the precipitation the
line in blue here and evapotranspiration the line in green here, rarely do those precipitation the amount of water we receive as precipitation the amount of water demand we have for evapotranspiration rarely do those line up the way we would like them to, so there’s periods of the year where there’s potential for excess water and potential
for need for drainage, and then there’s periods of the year where likely there’s some water deficit, and
certainly the soil can help buffer that, but there’s going to be times of those excesses
and deficits of water, and so the level of drainage that we need varies over the year as well as the level of the demand for water varies over the year, and so again drainage water management allows us to manage that drainage to better address both that excess and deficit water condition. But another important concept is that drainage water management only manages
the drainage outlet or the amount of drainage that we’re letting
leave the field, and so we’ve got water entering the system as precipitation, a large amount of that water leaving is evapotranspiration, some going to deep seepage and some running off the field as well as the water that leaving via the drain flow, but only drainage is the component that’s addressed via drainage water management. So although you may hear about controlling the water table drainage water management that’s only
true if we’ve got enough water in the system to have that water table to control, and so if the precipitation isn’t enough to actually raise the water table and then drainage water management won’t have any impact. If we want to actually raise the water
table in that situation then we’ve got to supply
water through subirrigation to make that happen. Another concept is that it’s really
limited to situations of flat topography, and so if we get more slope we lose that ability
to manage, and so we can deal with that somewhat by introducing more control structures but
at some point that gets impractical, so we talk about a 1 percent slope or less is where this is really applicable. But that’s still a large area, the North
Central Region that still lends itself to this practice about 31 million acres by this estimate that would be suitable. When we look at some results of the research on this practice this comes from an article summarizing a five states GIG project in the midwest on this practice as well as the results from other areas where this has been researched, and overall what we see is a reduction in the drain follow, so the amount of water leaving the field via drainage that reduction
ranging from 18 to 85 percent. Then when we look at the impact on
nitrate losses then another thing that’s been pretty
consistent from the research is that drainage water
management has little or no impact on the actual concentration of nitrate leaving with the drainage water, and so
really the reduction in nitrate loading leaving the field is primarily from that reduction in the drain flown, and so the reduction in nitrate load pretty well
matches that reduction in drain flow, and so eighteen to seventy-nine percent being kind of the range of nitrate load
reductions that we’ve seen from the multiple sites that have looked at this
practice. Do that again this is a practice that hopefully
benefits the environment but also potentially has some benefits to yield or to production, and so again kind of summarizing the research
that’s been done on this practice when we look at the impact on yield, there’s been several cases of yield benefits or yield increases
because of the practice, because of the ability to conserve some water at times, and so that’s ranged from 1 to 19 percent. Although up to 19 percent those yield
increases tend to be fairly modest more like 1 to 5 percent up to 10 percent in some
cases, but in many cases there’s no real effect on yield, and a lot of that just depends on the timing of rainfall, and so if we don’t get timely rainfall at times where we can capture it, then there is really not going to be much of an impact on yield. Typically haven’t
seen reductions in yield, although there was one case in some of the research
that did show a yield reduction on one site, but there is that potential if
the system isn’t managed well that we can have some reductions in
yield if we don’t manage that system well at times when there is some excess water
after the crops is in the ground. We looked at how the practices is typically managed, and certainly
there’s different scenarios that can be used. This is just one typical scenario. Once the crop is harvested in the fall, we would put some of these weir boards or risers or flash boards in the control
structure to raise that drainage outlet, and so then the water table would have to rise all the way to that level to be able to actually flow out of the system as drain flow, and so once harvest is done then at that point drainage really isn’t needed
in the field and so we can put those risers into the control structure and then hold back any water into the field that does occur over that non growing season
when the drainage isn’t needed, so by holding back that water we hold
back the nitrate that would leave with that water, and so again we reduced the amount of drain flow,
and then we reduced the amount of nitrate leaving with that drain flow. And so typically those those boards would
be placed within six inches of the soil surface or maybe about a foot below the soil surface, but raising up near that soil surface to hold as much
water possible back over that non growing season. And then in the spring when the drainage is needed so that the producer can get out in the field for
spring operations and planning then we would pull those boards, turn it back
into basically conventional drainage mode where we would lower that water table all the way down
to the tile elevation, let that system drain out, and let the field dry out so that we can get in a timely fashion and do those spring
operations, and then allowing a little bit of time for some root development nad to get the crop started, then we could put another set of boards back into that system to raise that outlet elevation. In this case, you know typical level maybe two-and-a-half feet below the soil surface
and now building in that capability that if we do get some timely rainfall to capture and store some of that water in
the field and make it available for that crop later on in the growing season. Again, that’s just one scenario there’s other scenarios depending on the goals of the producers as well as climate and other issues, but if we look at that throughout the year then again kind of starting at the
beginning of the year coming off of the last growing season, we’ve got those boards in the field to hold back that water, reducing drain flow and reducing nitrate loss with that. Then in the spring when
the drainage is needed we lower those, that outlet, let the system drain out,
get in and do our spring planning and other field operations, put the boards back in with the idea then of potentially conserving some water which also will reduce nitrate losses
but also save some water for the crop to use. Then when fall comes around if we need
some drainage prior to harvest we can pull some boards and allow that to happen. If we don’t need the drainage then
we can just leave the boards in, and then again once harvest is over put the boards back in to hold that water and potential nitrate
loss back, but again that’s just dependent on the outlet elevation, the actual water
levels is going to still depend on precipitation and water losses from
evapotranspiration and other losses, and so while we might like to have the water table where those blue lines are shown, this might be one typical scenario with the orange line here where again we got some excess water in spring, we drain that out and then maybe get a shot of rain in the
spring where we can save some water, in this case we actually show it coming up a little
bit over that, and so we would still have some drainage to
get it back down to the elevation we’ve set, but then as we move into the the meat of the summer then
evapotranspiration exceeding precipitation enough that the water table
drops, and we’re no longer controlling that
water table, and then showing again some water starting to build up in
excess in the fall after the crop is harvested. This has become a priority practice
picked from the NRCS because of its potential for both reducing nitrate
losses as well as improving production, and it’s a focus of the ag. water management team within NRCS, and I see some have joined us, and so one of the things that we’ve partnered with NRCS on is actually doing some training for those employees, so it’s been a hybrid approach, and so there’s a number of online modules that have been
developed to address this practice and some related practices, so there’s eight of those modules that
are out there. Those are available for folks that would like to view them and
like to learn more about this practice as well as again some of the related practices. They’re available at this forestrywebinars.net site. Probably easiest to just go to
that site and search for drainage water management, and you’ll find those online modules. Also did a series of onsite training sessions with those employees across the 10-state region and the
North Central Region, training just under 600 employees in that region. Another thing that we’ll be doing as part of
that project is actually our own little
upcoming webinar series hopefully starting this next month. Here are some of the topics that we’ll be
covering that so we’ll certainly be getting the word out through the North Central Region Water Network as well as other outlets and so again if it is something you are interested in keep your eye out for those webinars.
And with that, I’ll close off and turn it over to Richard. Great, Chris, thank you and why don’t we
just move right onto Richard here. So Richard Cooke is professor and drainage extension
specialist, you are probably seeing some commonalities here, in the department of Agricultural and
Biological Engineering at the University of Illinois and an adjunct professor in the Department of Agricultural Engineering at Njala University in Sierra Leone. He holds a bachelor’s degree in agricultural
engineering from the University of the West Indies Trinidad, a master’s
degree in Agricultural Engineering from the University of Guelph Ontario, and a PhD in agricultural engineering
from Virginia Tech. His current research focuses on the
development and evaluation of drainage related best
management practices for improving water quality, watershed scale monitoring of subsurface drainage systems, the development of multi-objective
design criteria for subsurface drainage systems, and the design of rainfall harvesting systems. He also
developed the online version of the Illinois drainage guide. So Richard I think is a master of all trades, and we’re happy to have him here with us today. Go ahead, Richard. Thank you very much. It’s indeed a privilege for me to be a part of this webinar. I won’t spend too much time talking about
excessive nutrient on the say the hypoxic zone because this is well
known to this audience. I would suffice to say that we are developing subsurface bioreactors for use in the mid-western region where it is heavily tiled for dealing with the some of these nutrient loss problems. A bioreactor is essentially a trench filled with wood chips through which
tile water is diverted, and then it is water treated before being passed back into the system. It consists of a diversion structure as well as a capacity control structure. This is like a top view of the bioreactor.
Water flows through the medium; the two ends aren’t connected hydraulically. It’s just
flowing through medium and a side view. Flow is controlled by the level of the
stop plugs or the weir boards in the diversion structure and the capacity control structure. Distribution is not necessarily
linear, but this is probably the best
approximation that we can show of the process. We also have structures where the tools the two control systems are combined, the two structures are combined, and in these systems there’s a chamber which causes a diversion into the bioreactor and another chamber through which we can control the capacity, and these are easy to install although they can’t be used if the structures are too big, the area treated is too large. In designing these bioreactors there are
several factors which we should consider which leads to uncertainty in the performance of these assistants. One is the use of a soil cover. In certain areas a soil cover above the bioreactor and this soil cover it reduces the hydraulic conductivity of or the
flow through its system, and so the flow will be less than
the design flow. So if it’s necessary then one can be put on
but otherwise there is no need to have a soil cover if there’s a bioreactor at the edge of the field in a field distribute. It has a very small footprint that these systems do. Another fact is the conductivity, in designing systems we usually use a conductivity value from the literature, and if we can determine a conductivity from a particular batch of wood chips, then we would have less uncertainty in the use of the system. We also use
a constant conductivity. However, while our research has shown that the conductivity, the effective conductivity in the bioreactor is not a constant. The conductivity
decreases over time and then when there is a spike in flow then the conductivity increases again, and then it falls back down. We think it’s due to the formation of biofilms in the, inside of the bioreactor, biofilms on the medium. Indeed we have found looking at the cross-correlation coefficient that there is a strong correlation between the conductivity and the flow six days prior to that event. So it’s possible then to develop some kind of model, Markov chain
model and to treat that conductivity not as a
constant but as a variable, and this would reduce our uncertainty in the results, and there is the residence time. The residence time is
controlled by the level of the upstream and the downstream stop plugs, and we can increase the residence time by decreasing the difference between these two heights, but if we decrease the residence time- if we increase the residence time we are decreasing the flow to the system and then there’s a greater potential for
bypass flow, flow bypass in the bioreactor. So we need to determine what is the optimum board settings for- to get the optimum performance of the bioreactor, and in our model which we have developed
there is room for playing with the settings to determine what the optimum settings would be in the system. And if we want bioreactors to be used more widespread and to be used in things like water quality treatment then there is a need to reduce or to identify any sort type of adverse effect and to deal with them. We have looked at some unintended consequences of bioreactors. For example, we find that almost invariably there is a slight increase in the dissolved reactive phosphorous coming out of the bioreactors. This is especially true when the bioreactors are new for the first few months, and although the values are
are small in this case there are less than 0.4 milligrams per liter, yet it’s real and it’s happened almost every time as you can
see from most of the literature, and people are working on ways to reduce this phosphorous either by adding medium to the wood chips for phosphorous removal or add in a separate chamber for phosphorous removal in some of these systems. Then we also looked at that dissolved organic
carbon which increases particularly in new bioreactors and then settles on a little bit more than the in a levels of organic carbon and of course dissolved
oxygen is usually down to close to zero. The combination of high DOC and low dissolved oxygen can have some adverse effects inside of the receiving stream, and so we have to be able to model this effect. This is particularly important if we are thinking of clearing up this system so that we have a whole host of bioreactors out in the landscape. And methyl mercury, with a redesign of the system we have addressed the methyl mercury problem, and indeed in
most of the instances where we now the methyl mercury coming out of the system is left under methyl mercury entering the system so
we think that problem has been licked, and in any case the
levels are rather low here and there are less than 1 nanogram per liter. The background level in natural systems
tend to be of the order of 0.40 to 2 nanograms per liter. So it seems that it is not a major problem. We also have to make sure that our
results can be replicated, and we can predict how the systems can perform if we are moving from say one part of the region to another or another part of the country, and when we looked at the bioreactor performance, we measure performance either in terms of percent nitrous load reduction or nitrate removal rate. It seems that nitrate removal rate is a type of measure of performance in that the variants are the stochastic component
of the relationship between the temperature and height and retention time and the removal rate is less than looked at the load reduction. The model which we have used and that I have developed, we have looked at the percent load reduction, and we are going to re-do these models instead look at the nitrate removal rate, especially if we can incorporate the effect of temperature on removal rate and if we know the water temperature we can do this, we can the sources say the we can predict the
temperature and the depth and the location, but reasonably, reasonable accuracy however, the water temperature of the water coming off of the tile at a given depth is not the same as the soil temperature, and so to reduce the uncertainty we have to
develop models so that we can predict what that water temperature would be. We have done some work on using solar energy for active and passive solar energy, to increase the temperature in bioreactors and we have achieved some
modest success; we have increased it by between 0.6 and 2 degrees Farenheit, but there’s much work left to be done, and this is one thing that we are going to be looking at over the next year or so. And if I could make some recommendations based on what we have learned about how we can reduce uncertainty in the bioreactors: one is to incorporate the variable hydraulic conductivity because that’s what occurs in the system, and it’s not hard to do, it’s a simple Markovian, Markov chain
model would be able to achieve that, and if we can use removal rates instead of the load reduction to
characterize the bioreactor performance then we can produce results
which would be more transferable and more predictable, and last if we
incorporate the effects of temperature then again we would reduce the uncertainty in our bioreactor systems. Thank you very much, and I look forward to any questions you
might have. Excellent. Thank you, Richard, so much, and now I am going to encourage everyone again, I’ve been sticking a couple questions in
the chat box here, but please those of you that are participating from other parts of the region feel free to put those questions in the chat box, and I will go ahead and start with Chris. Chris, I was just
curious if you could tell us a little bit about what farmers are saying about why they’re interested in it, or why they may
not be interested in having drainage water management installed or being practiced on their farms? Sure, you know, I think well one the farmers that are interested a part of that is they like that idea of a win-win solution where, you know, they feel like they’re having a positive impact on water quality, but they’re also getting something out of that through some potential yield increases. One thing that we try to be cautious about is not over selling what that yield increase is again because it doesn’t happen every year and the years that does occur it’s fairly modest but has been there, but we just don’t want to get them over
excited about that, but I think a lot of it really comes down
they like-the ones that are interested really like that idea of being able to
manage their drainage, that you know we talk about you wouldn’t sell
an irrigation system if you couldn’t control how much water went through that irrigation system but we install drainage systems where there’s no control over that drainage, and so this they can get some of that management tool that they didn’t have before. The ones that aren’t interested then oftentimes that’s because they’re not interested in actually managing drainage system; they like the idea that no other drainage systems
there now and I can forget about it, and not have to actually manage it. So that’s probably the common themes I hear. Great. Thank you. And Richard, how many bioreactors have been installed across the North Central Region, I wasn’t sure if Jane’s graphic was all inclusive or what can you tell us about that? I think maybe early book ken and the whole homes has been
installed in Illinois. In Illinois they started cost sharing on the system, I think it was last fall, but before that most of the system’s
interest on the stage were for purposes of research, and we installed I would probably say
between 15 and 20 bioreactors overtime in Illinois for research purposes. There have been other systems in Iowa and also in Minnesota and these are the ones that I know of; there’s at least one in Michigan as well and maybe in Indiana, but I’m not too sure. It’s a fairly new practice. Okay, great, and Jane or Chris, did you
have anything to add to that? I guess I can add that we’ve got three that we’ve been looking at in South Dakota with potentially plans for a couple more, and so
we’re just getting started here in South Dakota, certainly we’re not as far along as
they are in Iowa and Illinois. And it’s not widely used in Indiana either. There have been a few, but Illinois is certainly the leader here and maybe Iowa. Okay, thank you, and Shawn has a question, “Will it be difficult to characterize
performance of bioreactors on removal rate in parenthesis (nitrate removed per cubic meter per day) if the flow is not constant, won’t the rate be zero for any day that has zero flow? Yes, the rate will be zero for days that have zero flow. What we have done in our model is that we have used like a historic rainfall records through the drain model program, and then we can get like thirty years of data flow which have been predicted with the drain model program, and then we run this through the bioreactor based on the data flow and the stop plug settings, and hopefully we can incorporate temperatures as well, and then we’ll be able to get a better idea of what the removal rate would be. Right now we are just using an average removal rate, but we can refine that reduce in uncertainty in the measurement. Okay, thank you, and Kim has a question,
“How much storage per acre is needed to significantly reduce nutrient losses?”. And this is a great
question, and one I don’t have an answer for at this point, but it is exactly what our new project will be addressing to
get some orders of magnitude there. I’d also say there’s many ways to consider what’s a significant reduction of nutrient losses. You know, sometimes we think it needs to
be like statistically significant, but I think that’s not really the question here, it’s how many and
how much is needed to bring these down, because all
the practices that we’re looking at have a very small contribution at the watershed scale, but what that
means is we need a lot of them, but so it, you know, we can sort of
avoid the answer that way, but I think your question is exactly what we need to
start thinking about number, both how much nutrient losses we can get down and how much the ratio of pond volume to drainage area is needed and then again
to the area that water would be put on for example. All
these things we don’t yet have numbers, but I think they’re extremely important questions, so I’m glad you asked. Okay, thank you, and Jen Filipiak has a question, “What is the status of drainage water management and bioreactors regarding practice standards for NRCS cost share? That is could a farmer get cost share through equipped for each
practice?”. Who wants to take that one? Well, I can address certainly drainage water management that there is a national standard for drainage water management, a practice standard for that, the 5-5-4 standard, and so yes, it is eligible for equipped cost share. Again, it is one that has been a priority at the NRCS ag. water management team, and so there has been a considerable effort on trying to get increased adoption of that practice and cost-sharing for that, and bioreactors either Richard or maybe some of the NRCS folks that have joined us can fill in a little more on that. That one, I believe, is still a little more variable from state to state that I think some states don’t yet have
a bioreactor standard in place and others do and so that may be a little more state dependent. Right, that’s a good answer, and I would just say if anyone from NRCS wants to type a response in the chat box that would be
great, but that I believe that it is variable state to state still for bioreactors. I know that in Illinois the NRCS has started to cost share on bio- reactors, and they have been cost sharing on drainage water management for a while, so they’re both available for equip and Ruth I see if she can probably provide more information on that. Okay, and I would just add that NRCS is very actively looking at all these practices. There is a team that gets together and makes sure that the latest research is used and put into the practice standards, so it’s a very active area for NRCS as Chris said at the beginning, it’s a high-priority. Excellent, thank you. It looks like Ruth has some more, another response here, “The denitrifying bioreactor is an interim practice. Illinois and other states have adopted it, and are providing financial assistance”, and just for all
you, I’m reading these just make sure that when other people are viewing the webinar after we’re done that they hear what some folks have said in the chat box. Well Jane, I have a question for you. I know you’re just starting on your big new project and working with others on that project and
that you need some time to get some work done, but I know we’re going to be seeing some results from you before the the five years are over and can you tell
us, you know, when we might expect to see some things? Some results of various kinds coming out of the project? Oh, well there’s a good question. So some of the- we’re using existing field sites among others, so some of the sites have several years data already and so we hope more synthesis could be done in the first couple of years. Also, the economic analysis should be
done in the first couple of years, and the kind of questions like were asked about what would be the
benefits that we could expect from various sizes and those kind of things we would have in a couple years, then starting then we’ll start to build tools that others can use so that’s sort of in the 2017/2018, and then we’ll be doing a lot more
extension in 2019, so for sure we’ll be back to give talks in 2019 if
you can schedule us, Rebecca. Okay, thanks for the warning. I guess I’ll ask one more question related to drainage contractors, and I think all of you, you know, have been doing work with the
drainage contractors in your states and perhaps across the region, and I’m
just wondering how those folks are responding to these various, various practices and implementing them? In Illinois the contractors have taken to this practice like fish to water, and indeed like Land Improvement Contractors of America the group that I work with in Illinois, they have introduced a certification category for the installation of drainage water management, and so they have a training sessions on
this practice, and they are thinking of doing one also on bioreactors. And I can say the same in Indiana there
has been a great deal of interest by the most forward-looking contractors in becoming certified to as technical service providers for
this, and one of them who was the president
of the National Land Improvement Contractors I asked to be on an advisory committee for our project and was really impressed by how quickly he said yes and
enthusiastically, so that we’ll keep up that dialogue in all kinds of ways. So it’s a good question, that’s a very important audience that we work with. I guess speaking for South Dakota we’re a little bit of the Wild West here in drainage that a lot of new drainage that’s gone on here in
areas where there wasn’t drainage before, and so until recently our contractors have just been so overloaded with waiting lists that on there’s been some hesitance to try and spend some time on actually design systems for drainage water
management or some of these other practices, so there’s been some interest from certainly the more progressive contractors but a lot of them have just had their plates full and haven’t taken the time to really look at these more specific practices, but now that things have slowed down a little
bit I think we’re seeing more of an interest, and some of that’s being driven by the producers that are forcing the contractors to look at some of these systems because the producer interest in actually having some of these systems. Great, thank you and for the purpose of our post-webinar viewing audience Tim asks, “What is the status of the practice standards for saturated buffers?” and Ruth answers, “It’s an interim practice standard i.e. experimental and fewer states
have adopted it so far, fewer then the other practices that
we’ve been talking about today.” And then she also says, “Some states like Illinois are waiting
for results from research through conservation innovation grant so we
know more about how to design them.” Any comments from our speakers on saturated buffers? No, so I know there are about 15 that have been installed through these conservation, innovation grants and the research is just starting to come
in so that is the newest practice, but I think it seems promising. I think that the issue in our- especially in many of the flatest lands is that it wouldn’t easily fit into the landscape. It takes places where the
buffer is a little bit lower than the field, but there are some of these places and
what’s certainly true is there’s no practice that’s going to
work everywhere, and so it’s really important that we have a lot of tools in the tool kit and saturated buffers will certainly-
will likely be one of them, I shouldn’t say certainly since the research is still out there. Thank you, Jane. Okay, any final questions from our audience? Hearing or seeing none. Any final thoughts from our presenters before I go into the upcoming sessions? No. No, thanks everyone for joining us. Thank you all for your wonderful presentations and thanks to all of you that participated today. Again, please visit the northcentralwater.org website for
archived recordings of this session and other interesting
water topics. Some related to agriculture, some
related to urban and urbanizing areas, and our next upcoming session as I said at the beginning is on June 17th 2 p.m.
Central, 3 p.m. Eastern, and the topic will be cover
crops, and you can get a quick scan of the rest of them coming up on your screen. Thank you so much. Have a great rest of the afternoon, and hopefully we’ll see you at another webinar. Take care, everyone.

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