Irrigation and Fertigation Management

Tsz Him Lo Author

03/01/2018 Added

137 Plays

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Water Seminar

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[00:00:00.535]Welcome to this presentation.
[00:00:04.421]Has Dr. Daran mentioned,
[00:00:06.505]Daran is unfortunately unable to be with us here today,
[00:00:11.117]he's off touring in Brazil
[00:00:13.140]and so just here to represent the team
[00:00:15.170]and just to introduce, just a little glimpse of what we do,
[00:00:20.107]irrigation and fertigation wise in West Central Nebraska.
[00:00:23.705]So, I wanted to acknowledge all our funding agencies,
[00:00:29.124]since we're here, especially IANR and Water for Food
[00:00:34.039]and then just major collaborators
[00:00:35.870]that we've been working with
[00:00:37.385]both in northside and state wide.
[00:00:40.804]So, I was told that this is part of a class
[00:00:44.824]that is focused on water resources
[00:00:47.111]so just want to give a little bit of a water resources
[00:00:50.060]type of background.
[00:00:53.940]We classified the water resources challenges in our district
[00:00:57.536]in two ways, really commonly.
[00:01:00.149]Water quantity and water quality.
[00:01:02.384]To start with water quantity,
[00:01:05.350]ground water level declines
[00:01:06.750]have been recognized in our district for a long time
[00:01:09.596]especially in that south west corner, portion of our state
[00:01:12.481]in upper Republican natural resources district,
[00:01:15.184]that's been recognized for a long time and so,
[00:01:17.439]we have programs to slow that down
[00:01:20.272]or gradually eliminate that entirely.
[00:01:24.508]You've all probably heard of the Republican River Compact.
[00:01:29.963]Kansas wants our water, it's unfortunate
[00:01:32.351]so we're doing all we can to give them their stream flow.
[00:01:37.492]Also, especially in recent decades,
[00:01:41.271]we have a lot more concern about environmental
[00:01:44.400]in-stream needs,
[00:01:46.206]habitat in and along rivers.
[00:01:48.572]So the stream flow,
[00:01:49.897]we're talking about the Republican basin,
[00:01:52.770]and over here that's the Republican river,
[00:01:54.895]the wild life habitat more in the Platte River.
[00:01:57.496]But okay.
[00:02:01.421]Water quality commonly shown map, this is one of the most,
[00:02:06.196]this is the one for this year,
[00:02:09.212]just showing nitrate levels.
[00:02:12.065]We have a 10 part per million contaminate standard
[00:02:16.329]for drinking water.
[00:02:17.875]You see a lot of the areas along rivers
[00:02:19.838]are with surface water irrigation
[00:02:22.569]and also in the l-corn in North East,
[00:02:25.649]we have nitrate issues.
[00:02:28.197]We have some in our, we have a little bit
[00:02:29.750]of our fair share in West Central District too.
[00:02:34.737]So, how does irrigation and fertigation
[00:02:37.351]help to deal with all these water resources
[00:02:40.168]in the background?
[00:02:41.078]Well irrigation is really important for crop production,
[00:02:44.794]keeping plants photosynthesizing
[00:02:46.611]by opening those stomata,
[00:02:50.636]roots uptake nutrients through the soil water
[00:02:53.705]so keeping those accessible, that's really important.
[00:02:57.646]However that has a impact on our water resources.
[00:03:01.067]We're taking fresh water, we're consuming it
[00:03:04.014]and that's not flushing water down the drain,
[00:03:05.884]that's evaporating it, it no longer is in that water shed,
[00:03:09.254]or ground watershed, it's gone.
[00:03:13.302]And also when we make the soil profile wetter,
[00:03:18.859]that, the nutrients there can move downward more,
[00:03:23.351]that's what I would call the indirect nitrate leaching.
[00:03:27.069]That's probably more common now with more surface irrigation
[00:03:33.131]we used to leach nitrate directly
[00:03:35.428]by pushing water all the way through the root zone,
[00:03:37.736]that's less common now
[00:03:39.015]but that's how irrigation could impact
[00:03:42.762]the nitrate leaching.
[00:03:44.359]So, we're also not just moving the nitrogen,
[00:03:48.512]we're introducing new nitrogen
[00:03:52.068]from our petrochemical fertilizers,
[00:03:55.339]plants need nitrogen to make chlorophyll, proteins,
[00:03:58.102]all that important, all important for a good yield.
[00:04:01.588]But when we have greater end availability,
[00:04:04.299]we're gonna have more losses.
[00:04:05.895]That's just inevitable.
[00:04:09.004]Especially out here in Eastern Nebraska,
[00:04:10.699]a lot of single anhydrous ammonia applications,
[00:04:13.706]that is probably the cheapest by far,
[00:04:15.934]but you can have a lot of leaching.
[00:04:19.652]Especially with those low CEC soils,
[00:04:22.322]low clay content, low organic matter, or rainy springs
[00:04:25.776]as shown in this picture.
[00:04:27.921]That's pretty yellow corn.
[00:04:30.835]So, we've talked about these issues for decades,
[00:04:35.073]none of this is new, why are we still talking about it
[00:04:37.978]in the 21st century?
[00:04:39.462]Well I would say there are probably two major constraints,
[00:04:43.565]one is just the uncertainty.
[00:04:45.290]A lot of researchers here in the room,
[00:04:48.246]we know how indirect some of our measurements are.
[00:04:51.103]We're not really measuring water stress
[00:04:52.790]or nitrogen stress directly off the,
[00:04:56.618]so that's part of it.
[00:04:59.454]We are constantly developing mathematical models,
[00:05:02.420]we're finding mathematical models,
[00:05:04.339]we're not that good yet, still have room to work.
[00:05:08.617]And then with all these models or measurements,
[00:05:11.116]are at one point in time and space
[00:05:13.595]and then we have all the variability
[00:05:16.275]that we talk a lot about nowadays
[00:05:17.870]with precision agriculture.
[00:05:21.292]And so with all those combined,
[00:05:23.364]even if you have the best intentions,
[00:05:25.071]the most environmentally friendly mindset,
[00:05:29.918]that's just, that's just, you're still gonna be contributing
[00:05:34.031]something to some of these water resources problems.
[00:05:36.763]And then the whole economic background
[00:05:39.111]of crop production these days.
[00:05:43.044]Our cost of ground water pumping is still relatively cheap
[00:05:46.323]and so is nitrogen fertilizer
[00:05:48.123]and when you compare that even to a low corn price
[00:05:50.834]like last year 2017, irrigation,
[00:05:55.994]nitrogen is cheap insurance.
[00:05:59.408]And so, and to want to manage that more carefully
[00:06:04.505]you're investing time and money,
[00:06:06.470]whether that be sensors or models or consultants
[00:06:08.765]or you name it, equipment,
[00:06:12.441]that's what's happening.
[00:06:15.093]And so, I could see probably
[00:06:17.805]four future scenarios developing.
[00:06:21.107]Some of them are definitely less ideal than others.
[00:06:24.917]One is that clean water becomes scarce and depleted,
[00:06:27.620]that's happening to some of our southern neighbors,
[00:06:30.006]may that never happen to the State of Nebraska.
[00:06:33.500]Laws and regulations becoming stricter.
[00:06:36.587]That is happening and that will help some of the problems
[00:06:39.432]of the tragedy of commons but,
[00:06:42.419]but what we are mainly working on
[00:06:44.289]in the researching center's side
[00:06:46.108]is the last two, scientific tools
[00:06:48.709]becoming more reliable and more user friendly
[00:06:51.736]and growers becoming more stewardship minded.
[00:06:55.570]And so that's the overall mindset
[00:06:58.077]of our research team I would say
[00:07:02.031]and so the remainder of the presentation
[00:07:04.287]is focusing on three specific topics
[00:07:07.172]that we have been working on
[00:07:09.964]and that being, electromagnetic soil moisture sensors,
[00:07:14.820]variable rate nitrogen fertigation
[00:07:17.229]and this new flagship program from Dr. Daran Rudnick,
[00:07:21.756]testing agricultural performance solutions
[00:07:23.992]called UNL-TAPS.
[00:07:25.333]I'm gonna talk about all those in much greater detail
[00:07:27.335]for the rest of the presentation.
[00:07:30.381]So, an example of an installation in soybeans.
[00:07:37.890]So, in terms of soil water management,
[00:07:40.919]you might think of the soil as the sponge,
[00:07:43.520]this reservoir that's holding water
[00:07:45.990]for future plant water uptake.
[00:07:50.324]Typical corn irrigation recommendations look like this.
[00:07:55.873]You leave some room in that profile to store some rainfall
[00:07:59.277]that you get in this growing season,
[00:08:01.582]during that late vegetative early reproductive part
[00:08:05.076]and then as your corn gets closer to maturity,
[00:08:08.019]you start drying down that soil moisture profile.
[00:08:11.365]It's really difficult to follow this if you have no idea
[00:08:14.868]how much soil water is in the ground.
[00:08:17.907]I've tried to do this, it's hard.
[00:08:22.365]So, in this, in our current situation
[00:08:28.553]there are actually many growers that are gradually adopting
[00:08:32.150]these electromagnetic sensors
[00:08:33.865]as a convenient method of measurement.
[00:08:35.725]So, that is something that they are gradually using
[00:08:38.375]so, that's the context within which we work.
[00:08:43.995]In the past, for the past two years,
[00:08:46.616]our research team has focused
[00:08:47.986]on primarily these several sensors.
[00:08:52.345]A lot of these sensors work by sending a voltage pulse
[00:08:55.941]down these rods
[00:08:58.095]and then, the speed in which these voltage signals travel
[00:09:02.095]is determined by water.
[00:09:04.048]The more water, the slower these signals travel.
[00:09:06.829]And then when it reaches the end of the rod
[00:09:09.360]it bounces back so,
[00:09:11.188]we get to measure that travel speed
[00:09:12.967]and we corresponding to water.
[00:09:15.934]Others use the soil as a part of their circuit
[00:09:19.286]and so this frequency at which this electricity oscillates
[00:09:23.277]within that circuit is also determined
[00:09:25.429]by the amount of water in the soil.
[00:09:28.185]So, that's a brief and best way I can explain it.
[00:09:36.859]So the typical approach that irrigation engineers use
[00:09:43.301]when they do soil moisture sensor research
[00:09:45.667]is accuracy assessment.
[00:09:47.568]And we've done our fair share of that.
[00:09:50.453]And what you do is you keep comparing what you get
[00:09:53.437]from these sensors based on their factory calibration,
[00:09:56.354]what they would output by default
[00:09:59.186]and then you compare it with a certain reference.
[00:10:03.750]The two references we have primarily used
[00:10:05.933]in our research team is one, the neutron gauge.
[00:10:09.871]It shoots out these radioactive neutron circuits,
[00:10:12.109]slowed down by water
[00:10:12.974]and then we measure the ones that are slowed down.
[00:10:15.787]Or in the lab we put all the soil in this PVC ring
[00:10:20.033]and then we weigh it.
[00:10:23.803]So, if you do this enough, then you're able to draw a trend
[00:10:30.244]and that we call a local calibration,
[00:10:32.418]thinking that if we know the information that we know now,
[00:10:36.450]we can kinda more accurately predict
[00:10:38.420]what amount of soil water is in the ground.
[00:10:41.967]Results would probably look, some results
[00:10:45.029]could maybe look like this
[00:10:47.868]for different amounts of reference moisture content.
[00:10:52.410]You have a certain sensor reported content,
[00:10:55.069]you might do it enough times, you have this curve,
[00:10:57.975]you draw it
[00:10:59.652]and this particular set of results, most of these sensors
[00:11:02.720]are overestimating soil water
[00:11:05.756]and a lot of these trends are curvilinear.
[00:11:10.464]And we did this in two steps.
[00:11:13.256]So okay that's all well and good, lots of people
[00:11:15.772]will do this.
[00:11:16.971]You could probably write a paper
[00:11:18.158]by doing this at every single different field site,
[00:11:22.681]that's good for publications
[00:11:24.347]and tenure expose to a certain degree,
[00:11:26.906]but how useful is that?
[00:11:30.633]What other way can the calibrations that we develop differ
[00:11:35.655]when we do something else,
[00:11:37.653]for example, how far geographically
[00:11:40.165]can I transfer these calibrations?
[00:11:42.258]Can I go across the street?
[00:11:44.562]Can I go to the next section or county or state?
[00:11:50.480]What happens if I pull it out in the soil again next year?
[00:11:55.220]A lot of these sensors measure a very small soil volume
[00:11:58.593]so, is what I'm measuring really representative
[00:12:02.271]of what I need to manage as a grower
[00:12:06.122]and also, it's been widely reported that
[00:12:08.772]each one of these devices,
[00:12:10.246]because they're electrical, they have electronics in them,
[00:12:13.445]that there's differences,
[00:12:14.786]sometimes in the circuits and the measurements.
[00:12:16.757]So I may or may not need to account for that.
[00:12:21.685]So okay, so then I'm questioning
[00:12:25.534]why am I spending all this time
[00:12:27.476]doing all these calibration activities, I.
[00:12:31.377]But, and also talking with multiple growers,
[00:12:34.301]one of which is in the room,
[00:12:37.359]they don't use the absolute value reported by these sensors.
[00:12:42.023]So why do I care so much about the accuracy of that value?
[00:12:48.757]So there have been researchers
[00:12:49.967]that have also looked at this.
[00:12:53.279]They track these lines
[00:12:55.441]and then they see when the slope changes right,
[00:12:57.574]so maybe this section you see a pretty steep slope
[00:13:00.755]and then later in the graph you have this shallower slope
[00:13:04.848]and so okay, maybe that, the point where this changes,
[00:13:09.025]the slope changes is called the breaking point,
[00:13:10.944]maybe that has some special importance
[00:13:13.382]to plant water status.
[00:13:18.574]But you see, if you look at the slope of the line,
[00:13:21.866]that's influenced by weather conditions.
[00:13:23.896]The dryer and hotter it is, the steeper the line's gonna be
[00:13:26.457]because that's when the plants are taking up more water.
[00:13:29.534]So okay weather conditions are important.
[00:13:32.500]And these researchers, Thompson et al in Spain,
[00:13:35.679]they looked at really small root zone
[00:13:38.269]and so you only have one sensor there.
[00:13:40.309]So what happens is then, by the time you realize
[00:13:45.268]that you have changed the slope of the curve,
[00:13:48.185]you're already water stressed.
[00:13:49.779]Okay, that's not very helpful.
[00:13:52.654]I'm knowing that I'm stressed after the point
[00:13:55.569]when I should have irrigated,
[00:13:57.073]so that's all just post-mortem analysis, not helpful.
[00:14:02.050]But we have a little bit different situation
[00:14:04.907]here in Nebraska.
[00:14:06.145]Our soils are much deeper and I should say,
[00:14:09.741]the crops we grow are more deeper rooted.
[00:14:15.196]Our soils are relatively more water holding
[00:14:17.959]and so, if you monitored enough depths,
[00:14:21.384]you could probably come up with something
[00:14:24.757]and especially with the growing popularity
[00:14:27.762]of these multi-sensored capacinous probes with
[00:14:30.884]oops, five, six, 12 different sensors in the same probe.
[00:14:37.474]You could maybe do this,
[00:14:38.796]even if in terms of the actual accuracy
[00:14:41.762]of the volumetric water content
[00:14:43.286]it may not be that accurate.
[00:14:45.987]And then we spend all this time talking about accuracy
[00:14:47.959]but growers care a lot about some other characteristics
[00:14:51.332]of soil moisture sensors.
[00:14:53.801]All classified under the category of convenience.
[00:14:57.032]Installation.
[00:14:58.678]If you manage a 5000 acre farm,
[00:15:01.522]you may not want to go with a soil probe
[00:15:03.310]and install your own soil moisture sensors,
[00:15:05.625]you may want dealer service.
[00:15:07.270]But with dealer service, this probably means the sensor
[00:15:09.670]is gonna be much more complicated
[00:15:11.750]than the sensor that you have self-service for.
[00:15:14.363]So pick your poison.
[00:15:17.064]Also, sensor shape matters how you install the sensors.
[00:15:21.799]You can look at this horse shoe shaped center sensor,
[00:15:24.856]you probably need to dig and then push it in
[00:15:27.793]and then backfill.
[00:15:29.181]If you have a sensor like this,
[00:15:30.392]this is more like a wire mark shape.
[00:15:32.313]Stick a PVC, glue a PVC pipe to it, you probe and auger
[00:15:37.323]and then insert, done.
[00:15:40.188]Power requirements.
[00:15:42.231]If you do any spraying at all,
[00:15:44.333]you may not want solar panels in your field.
[00:15:48.498]A year long battery might be kinda nice.
[00:15:53.203]A lot of research type sensors
[00:15:55.304]are currently connected to data loggers.
[00:15:59.469]Those are sometimes expensive and, at,
[00:16:05.210]we recently had a situation where a 3 1/2 inch frame
[00:16:09.608]pushed a lot of water into our data logger box
[00:16:12.342]and causing one of the data loggers
[00:16:13.570]to have to be sent back for service,
[00:16:15.702]that might not be something you want to do
[00:16:18.546]but that just has to do with Him's poor installation print.
[00:16:22.005]Anyways, data access.
[00:16:25.315]A lot of growers want
[00:16:26.523]to have information on their smartphones
[00:16:29.157]or on their computers.
[00:16:31.270]Web interfaces are increasingly important.
[00:16:34.732]Manual download is maybe too tedious.
[00:16:37.597]And then also for some NRCS programs,
[00:16:39.709]you need to generate documentation for soil moisture use,
[00:16:43.672]so the ease of generating those reports,
[00:16:45.602]those are all very important considerations.
[00:16:49.625]So, next steps from my perspective,
[00:16:53.395]maybe look more at trends than the absolute accuracy.
[00:16:57.560]And then we have to move back to the field scale.
[00:17:02.862]The field on the right has a old gravel-y stream bed,
[00:17:08.112]that's all too familiar.
[00:17:11.263]This field has very eroded side slopes.
[00:17:14.819]Some people in the room can tell you
[00:17:16.943]when they hit gravel when they dig that but, anyways.
[00:17:20.517]So,
[00:17:24.713]the classic questions of how many sensors,
[00:17:29.235]inferring information from one sensor
[00:17:31.206]to the rest of the field,
[00:17:33.116]dividing into zones,
[00:17:35.482]the classic start stop,
[00:17:37.728]and all those kinds of things.
[00:17:42.085]So, that would conclude kind of,
[00:17:47.480]I didn't give you a whole lot of
[00:17:48.760]new scientific information there
[00:17:50.122]but just kind of describing the kinds of things
[00:17:52.783]we've been doing and the way we're thinking
[00:17:56.124]and this next section might be a little bit similar,
[00:17:59.740]talking about the topic of
[00:18:00.848]variable rate nitrogen fertigation.
[00:18:05.815]You got the, urea ammonium nitrate solution here,
[00:18:11.821]you have your pump, Ken valve,
[00:18:15.867]some injection pump control panel, DFD, so on and so forth.
[00:18:22.214]Okay, so why fertigate at all.
[00:18:25.131]So fertigation is a method of
[00:18:27.395]in-season fertilizer application.
[00:18:30.524]So, traditionally with one time
[00:18:34.059]anhydrous people would put it in the fall,
[00:18:37.235]plants aren't taking that up at all.
[00:18:41.028]We talked about the losses earlier.
[00:18:42.836]You wanna synchronize, ideally you wanna synchronize
[00:18:45.322]when those nutrients become available to plant
[00:18:48.078]and when they actually get taken up,
[00:18:50.971]just minimizing that window where they can be lost.
[00:18:55.930]So fertigation that,
[00:18:57.372]this terminology combines fertilizer and irrigation,
[00:19:01.374]so it means adding fertilizer to irrigation water.
[00:19:06.454]This is just one of many methods
[00:19:08.831]of applying in-season fertilizer.
[00:19:11.362]Some of the other alternatives
[00:19:13.423]include a high clearance applicator,
[00:19:16.137]kinda like a sprayer with long drops
[00:19:19.976]and then airplanes too actually,
[00:19:23.187]that was new to me, but apparently
[00:19:24.496]you can make that work quite well.
[00:19:27.768]And you can feel you have the irrigation system there
[00:19:30.867]so you can use it to apply fertilizer.
[00:19:34.178]Since you have, as we just mentioned,
[00:19:36.852]if you have that system already,
[00:19:38.750]the equipment costs can be minimal,
[00:19:41.411]there are some things you need to do it
[00:19:42.975]for environmental compliance, safety, that kind of stuff.
[00:19:47.031]If you're already irrigating,
[00:19:48.026]labor requirement and application cost,
[00:19:50.424]all those are pretty minimal.
[00:19:53.977]And one of the advantages I see is,
[00:19:56.722]especially in more rainy parts of the state,
[00:20:00.176]side dress can be difficult to time
[00:20:02.655]because you just can't get into the field,
[00:20:04.065]it's just way too muddy,
[00:20:06.361]irrigation even if the soil is pretty wet,
[00:20:08.100]you can put down a quarter inch
[00:20:09.339]and apply some fertilizer when you need to.
[00:20:12.102]Just so, the timing it's a significant advantage.
[00:20:20.737]Okay so how do you know when and how much fertilizer
[00:20:24.476]and that kind of stuff.
[00:20:25.694]So, predictive is probably the most common.
[00:20:30.641]You just pick a certain growth stage schedule.
[00:20:34.734]This is a graph produced by Iowa State,
[00:20:39.295]just tracks how much nitrogen it's taking up,
[00:20:41.908]by different growth stages, you can use that as a reference.
[00:20:46.093]Or you can do a reactive approach, let the plant tell you
[00:20:49.629]when it needs nitrogen, whether that tissue sampling
[00:20:52.601]or crop canopy sensors,
[00:20:55.500]hopefully you don't wait until your corn looks like this,
[00:20:57.796]that's way too late.
[00:21:01.300]Okay so, you might ask okay so I can see when the corn
[00:21:05.729]starts turning a little bit yellow,
[00:21:07.041]why do I need to use a sensor?
[00:21:08.869]Well sensors are just a little bit more sensitive
[00:21:11.032]than your eyes and they also give it an absolute number,
[00:21:13.978]you might just be able to say this leaf
[00:21:15.479]is greener than that one
[00:21:17.147]or this doesn't look quite very green,
[00:21:20.114]hard to come out with a pounds of nitrogen for that.
[00:21:24.093]So what active sensors means is that,
[00:21:27.161]it admits this modulated light,
[00:21:30.060]that's different than sunlight
[00:21:31.774]and then it gets reflected by the leaves
[00:21:33.596]and it detects that light only.
[00:21:36.113]So that means it's unaffected by cloud cover
[00:21:40.187]and sun angle and all those kind of things
[00:21:42.068]that make the amount sensing typically very difficult.
[00:21:48.012]And then you can compare those measurements
[00:21:49.681]with what you get with plants
[00:21:53.036]that you know are nitrogen rich,
[00:21:55.413]whether you have a well fertilized strip
[00:21:57.382]or use a statistic approach, whatever.
[00:22:00.329]And you can mount these sensors
[00:22:01.416]to a bunch of different moving things.
[00:22:06.617]People, vehicles like tractors and sprayers
[00:22:10.559]and they're doing drones more and more these days,
[00:22:14.925]center pivots, you name it.
[00:22:18.413]So I wanna take the time to do a commercial break.
[00:22:22.373]I want to invite you all to go
[00:22:24.224]to this presentation next Friday.
[00:22:27.170]One of our collaborators Dr. Brian Krienke
[00:22:30.290]is talking about using these canopy sensors
[00:22:33.730]and a particular nitrogen model called Maize-N
[00:22:36.629]to manage fertigation.
[00:22:38.292]So if the little bit that we just talked about
[00:22:41.171]or what comes after interests you, you can go to that,
[00:22:44.928]this is one of the core areas of expertise
[00:22:47.273]I would say at UNL,
[00:22:48.567]so, if you're at UNL you could go learn more about it.
[00:22:55.057]Okay so that's more field scale, flat rate zone mostly,
[00:23:01.589]so why variable rate, why site specific amounts?
[00:23:06.703]Well we sometimes have a non-crop areas within fields
[00:23:11.445]whether that be the water way right here
[00:23:14.282]or you got areas that got washed out
[00:23:17.419]and now it's just overtaken by weeds and grass,
[00:23:20.223]you don't need to place fertilizer there
[00:23:23.282]or in the former case of the water way,
[00:23:25.416]that's pollution if you just directly dump fertilizer
[00:23:27.537]into your water way.
[00:23:29.549]Or you could have, be a researcher,
[00:23:31.064]you need to do all these fertilizer treatments
[00:23:32.974]and it might be easier to do it with irrigation,
[00:23:36.619]it may or may not.
[00:23:39.670]And then, profitability wise and environmentally wise,
[00:23:44.749]when you have spatial variability in your field,
[00:23:47.562]differences in your field,
[00:23:49.309]you may wanna reduce that nitrogen fertilizer
[00:23:51.657]on areas that you know aren't gonna produce well.
[00:23:56.197]And so, that's just reducing the fertilizer
[00:23:58.646]that's not gonna be taken up, then gonna be lost so,
[00:24:02.303]better for your bottom line and better for the environment.
[00:24:05.595]And for some crops,
[00:24:06.782]there's this phenomenon of excessive vegetative growth,
[00:24:11.890]meaning, if you apply too much fertilizer
[00:24:14.923]in this vegetative period
[00:24:16.264]before it bares that fruit, that yield component,
[00:24:20.458]it just grows a lot of leaves
[00:24:22.663]and then it actually doesn't contribute
[00:24:25.172]to a good yield quantity or quality at the end
[00:24:27.851]so, that's gonna be especially important for those crops.
[00:24:33.187]Not so much for corn and soybeans
[00:24:34.191]but we're developing that technology,
[00:24:37.429]working with that technology right now with corn.
[00:24:41.684]So in our situation, our variable rate fertigation system
[00:24:48.177]consists first and foremost of a center pivot,
[00:24:51.430]that's a revolving sprinkler system.
[00:24:53.896]The slower it moves, the more water it applies
[00:24:56.408]because the pump is still pumping the same amount
[00:25:00.927]and when you slow it down, it's covering less acres and so,
[00:25:04.343]that's more water.
[00:25:05.786]You can apply different amounts of water
[00:25:07.440]by just doing the, speeding up and slowing down
[00:25:11.463]or you can have these valves.
[00:25:14.624]So, up here, if you go twice the speed
[00:25:19.419]then you apply half the water.
[00:25:22.710]Here is an example of the solenoid valve,
[00:25:27.351]open and close and pulse and all that kind of stuff,
[00:25:30.552]Dr. Yen will talk about more about VRF specifically
[00:25:33.167]in a later seminar
[00:25:35.474]but that's the common technology piece.
[00:25:40.738]Okay so, but if you want different amounts of fertilizer,
[00:25:44.098]you can either do it with your different amounts of water
[00:25:46.038]or you can do it with different concentrations of fertilizer
[00:25:48.912]in that water.
[00:25:50.192]So the second component definitely is the injection pump,
[00:25:52.704]injects the chemicals.
[00:25:54.532]So it's just a metering pump, positive displacement,
[00:25:57.912]not too special.
[00:25:59.702]There's always been this manual dial
[00:26:03.520]where you can crank down that stroke length,
[00:26:08.252]the discharge per stroke.
[00:26:13.306]But with variable rate typically what happens
[00:26:15.114]is you use variable frequency drive
[00:26:17.787]to speed up and slow down the motor.
[00:26:20.001]I mean there are models that also mess with that but,
[00:26:24.999]the version we're using is mostly achieving
[00:26:28.018]the variable injection through variable frequency driving.
[00:26:32.987]So you could say there is two approaches to this,
[00:26:36.380]one is a variable rate injection.
[00:26:39.590]So you wanna maintain the same concentration of fertilizer
[00:26:44.255]when your water flow rate is changing
[00:26:46.693]because of those opening and closing of valves.
[00:26:49.444]So you always want that injection rate
[00:26:52.510]to be proportional to your flow amount.
[00:26:54.738]So we did this test using this particular company product
[00:26:58.607]where it's connected to our irrigation flow meter.
[00:27:02.376]We varied the flow rates from 100 to 500 gallons per minute.
[00:27:07.344]We were able to get a pretty consistent fertilizer
[00:27:09.731]to water volumetric ratio
[00:27:12.281]which is the concentration.
[00:27:15.990]It's really good, this works.
[00:27:19.738]That's giving a new macrometer propelemeter
[00:27:23.517]so the condition of the flow meter would matter
[00:27:27.836]because obviously if the flow meter is deteriorating
[00:27:30.770]and it's going off, then being proportional to something
[00:27:33.878]that's not accurate is not meaningful.
[00:27:38.937]And six minute round is probably,
[00:27:41.590]most parts in the field
[00:27:42.451]are gonna get water for at least that long
[00:27:44.998]so that's a good,
[00:27:49.482]that's representative of what accuracy we'd be getting
[00:27:52.611]in terms of concentration.
[00:27:54.866]So another method, you could keep that
[00:27:56.877]injection rate just constant.
[00:27:59.438]If you oversize your sprinkler nozzles,
[00:28:02.343]one thing you can do is oh if I want less fertilizer here
[00:28:05.765]I can pulse these so that,
[00:28:09.292]the sprinklers aren't shooting as much water
[00:28:11.100]but then I open them more on this other part of the field
[00:28:15.164]and just keep that overall water flow rate constant.
[00:28:18.313]If you do that with the constant injection
[00:28:20.527]then your fertilizer concentration's gonna be constant.
[00:28:24.063]Otherwise it's more complicated,
[00:28:25.871]but we've also been able to do that.
[00:28:28.289]Unfortunately the day we did this catch contest
[00:28:30.413]it was really windy
[00:28:33.713]and so we weren't able to catch the volumes
[00:28:36.893]that we were supposed to
[00:28:38.611]but by doing some adjustments
[00:28:41.049]we find that yes, it's able to follow the prescription
[00:28:45.885]even with this more complicated situation,
[00:28:48.364]we'll see what the reviewers say about this.
[00:28:52.619]So that's all the opening, closing of valves.
[00:28:57.576]That's complicated, that's costly.
[00:29:00.757]We have this other alternative
[00:29:01.883]of just doing the speeding up and slowing down
[00:29:04.026]or just doing the, injecting more, injecting less so,
[00:29:08.112]we control, we'll control the fertilizer
[00:29:10.164]in terms of pie slices or sectors of the circle.
[00:29:14.663]We believe that there should be some of the variability
[00:29:17.783]and requirements that do follow this kind of shape,
[00:29:21.733]so, but this would have some merit.
[00:29:26.102]You're avoiding the much higher price and maintenance
[00:29:29.799]of these sprinkler control technologies
[00:29:32.563]while getting some of the benefits
[00:29:34.054]of these variable rate size specific nitrogen application.
[00:29:37.975]So I would definitely argue that this is a low risk
[00:29:41.206]and practical first step into this technology.
[00:29:45.430]I've been wanting to test this on somebody's field
[00:29:48.651]but I'm too busy, anyways.
[00:29:53.185]Something we want to look into but,
[00:29:56.098]when we have more time and resources.
[00:29:58.914]Okay, so those two would be kind of the management,
[00:30:05.109]practices, research technologies
[00:30:08.626]that I've just talked about,
[00:30:10.768]both the soil moisture sensors
[00:30:12.351]and the variable rate fertigation.
[00:30:15.595]This is our kind of just putting everything together,
[00:30:17.911]kind of a new way to do extension,
[00:30:20.694]new way to connect with growers, Daran's brainchild
[00:30:27.524]and something that's really been our focus lately
[00:30:33.558]and so I just want to talk to you about
[00:30:36.057]some of the concepts behind this
[00:30:37.671]and also, just some of our results from the previous year.
[00:30:43.543]First of all traditional extension.
[00:30:48.349]University does research, growers adopt findings,
[00:30:51.551]it's one way.
[00:30:53.866]Unidirectional.
[00:30:56.018]Assumes the university has some sort of answers
[00:30:58.549]that growers just need to assimilate.
[00:31:04.534]That can work well with technical issues,
[00:31:08.240]for example, what type of flow meter is more accurate?
[00:31:13.116]There is probably a standard answer for that
[00:31:17.464]given upstream length, downstream length,
[00:31:21.650]Dr. Azinar is here so I need to be careful.
[00:31:26.354]And then, but there is a lot of things we talk about
[00:31:30.505]in irrigation and fertigation management
[00:31:32.538]that are not, they're technically related
[00:31:37.091]but they're not technical.
[00:31:40.333]Just the whole, things about thinking and behavior,
[00:31:45.716]the people that don't turn off their pivots.
[00:31:49.577]Just this aversion to using soil moisture sensors
[00:31:56.717]or something like that.
[00:31:58.191]There's a lot of things that are not just a particular,
[00:32:01.462]you just buy this product and it will solve your problems,
[00:32:03.524]it has to do with thinking and behavior
[00:32:06.603]and some of these issues are best solved
[00:32:09.467]by learning from peers,
[00:32:11.041]from other growers, not from a university farm
[00:32:13.865]where the plot size is about the size of this table.
[00:32:20.114]With people that have similar constraints
[00:32:22.519]rather than drastically different ones,
[00:32:26.503]and also technology only becomes a practice
[00:32:30.354]when it somehow gets put into each grower's unique
[00:32:35.300]and complex business operation and way of life.
[00:32:38.066]That's really what's happening.
[00:32:40.809]The big things of switching from tilled systems
[00:32:43.977]to no-till systems or something like that.
[00:32:45.878]The big questions, there has a lot to do,
[00:32:49.798]there is a lot more than just buying this thing.
[00:32:55.384]So, there's two alternative models that exist,
[00:33:03.205]there's probably more but I'll name two,
[00:33:05.522]one is on-farm research and the way I would put it is,
[00:33:08.978]try it at home.
[00:33:11.426]So it's definitely most informative for the grower
[00:33:14.156]where this is taking place.
[00:33:15.987]You do the experiment on your own farm
[00:33:19.035]to know whether it works on your farm.
[00:33:22.956]It accounts for the differences
[00:33:24.064]between you and the next door neighbor.
[00:33:27.914]Between your field A and your field B.
[00:33:32.546]The downside for researchers is that not all growers
[00:33:35.240]want to experiment with all practices.
[00:33:40.246]For example if you wanna experiment with deficit irrigation
[00:33:42.278]you better be willing to compensate somebody.
[00:33:45.175]But in, because you could have locations
[00:33:48.995]scattered all across the state,
[00:33:50.620]you could have really difficult time trying to collect
[00:33:53.930]enough supplementary data to come up with a theory or,
[00:33:59.153]and because there are so many differences
[00:34:01.641]between all these farms
[00:34:02.790]because of grower management, past history in fields
[00:34:05.675]and all that, it's hard to generalize findings.
[00:34:10.978]So, Daran's idea is this on-station competition,
[00:34:16.398]which to summarize it, it would be called,
[00:34:18.777]try it somewhere else.
[00:34:22.119]Meaning you try it at the experimental station
[00:34:26.224]instead of your own farm.
[00:34:27.302]It's probably the smallest risk and investment you can make.
[00:34:32.137]It minimizes any background effects
[00:34:34.381]between different farms
[00:34:36.059]because you all do it on the same field
[00:34:37.713]by the same people that use the same equipment.
[00:34:41.391]So you really are comparing apples to apples,
[00:34:44.651]'cause it's at the experimental station,
[00:34:48.298]we don't pay property tax.
[00:34:50.250]So we are, financially we're a lot more flexible
[00:34:54.516]we can really implement some treatments
[00:34:56.291]that damage yield a lot.
[00:35:00.458]We can, it's right in our backdoor so,
[00:35:05.934]we could collect data as much as we need to,
[00:35:10.280]if we have the graduate students that are willing to do it.
[00:35:14.388]And but then you're still doing it not on the field
[00:35:17.281]where this is really gonna happen,
[00:35:18.906]so there's still this transferability gap that could happen.
[00:35:23.956]So that's a potential weakness.
[00:35:27.743]But given all of the advantages we see,
[00:35:31.381]I would say that this is a pretty good extension idea.
[00:35:34.908]So last year was the first year this happened,
[00:35:37.691]the UNL-TAPS Competition started out
[00:35:39.731]with the following idea,
[00:35:42.576]using three eighth acre plots to simulate 3000 acres
[00:35:47.300]of no-till irrigated corn following soybeans.
[00:35:51.252]Contestants, which there were 12 actual competing teams
[00:35:59.066]plus a UNL professor team.
[00:36:02.093]They got to make six different kinds of decisions,
[00:36:05.199]one was insurance selection.
[00:36:08.046]Then nitrogen management,
[00:36:09.793]both pre-plant and in season.
[00:36:12.292]And then at planting a hybrid selection, seeding rate.
[00:36:15.834]Irrigation management, we irrigate twice a week
[00:36:18.671]and you got to pick anything between zero to one,
[00:36:22.825]I think we did, 1.2 inches max.
[00:36:26.706]And grain marketing.
[00:36:28.758]So trying to capture
[00:36:32.837]a significant part of in-season decisions
[00:36:35.532]that growers actually make.
[00:36:37.726]Alright so, I said there are 13 teams,
[00:36:41.433]including UNL, there were two kind of benchmark farms.
[00:36:45.572]So you'll see one that doesn't get any inputs,
[00:36:49.440]that's the no input control.
[00:36:52.305]So just starting with the insurance,
[00:36:54.520]you have people that did not buy any crop insurance
[00:36:57.251]to people who spent more than
[00:36:58.368]$100 per acre on crop insurance.
[00:37:02.620]Planting, we got the whole gambit.
[00:37:05.286]Most of the major corn seed companies are represented,
[00:37:09.485]seeding rates span the whole irrigated range
[00:37:12.126]that people typically put from 28 to 34.
[00:37:18.120]Longest relative maturity was probably 113 day,
[00:37:22.781]that we're a little bit below 110, just wide range.
[00:37:30.218]Nitrogen fertilizer, we gave them the option of pre-plant
[00:37:34.891]on with the coulter machine
[00:37:37.817]and then the side dress
[00:37:38.775]using the same machine about the six.
[00:37:41.436]Fertigation we offered, four, yeah four times
[00:37:47.606]that they could fertigate
[00:37:49.331]and so, all the, from, besides the no nitrogen control,
[00:37:58.006]you got maybe slightly shy of 150 pounds
[00:38:00.650]all the way to close to 250.
[00:38:02.905]This is corn following soybeans so some of them,
[00:38:04.510]they are definitely applying too much.
[00:38:07.508]But irrigation, again, the no input control,
[00:38:13.218]but anything from a little over two, to almost 11.
[00:38:18.751]And the timing of the irrigation also differs.
[00:38:24.462]At the same time, while we're doing all this management,
[00:38:27.733]we gave the growers access to a whole bunch of technology
[00:38:30.711]that probably they won't have all of them on their own farm.
[00:38:35.547]For example, some of them are more traditional,
[00:38:39.041]soil tests from WARD Laboratories,
[00:38:42.219]this Verberate coulter system, with SureFire planting,
[00:38:50.486]with Precision Planting
[00:38:51.473]and Martin Till for wheel cleaners,
[00:38:55.719]Lindsay for irrigation, Agri Inject
[00:38:57.989]for their fertigation,
[00:38:59.779]Li-Cor supplied an net icoverence system
[00:39:01.933]giving real time ETD data on an adjacent field,
[00:39:06.641]AquaSpy sold Capacencs soil moisture sensors,
[00:39:09.863]two companies providing imagery,
[00:39:11.481]AirScout providing aerial
[00:39:12.659]and FarmersEdge providing satellite.
[00:39:15.025]FarmersEdge also supplied a little on-farm weather station
[00:39:19.710]so there was that too.
[00:39:21.852]So a lot of information they could use
[00:39:24.597]to make these management decisions.
[00:39:28.731]So at the end, the results.
[00:39:34.129]On the Y axis, you here, you have profit per acre.
[00:39:37.038]We're close to 150 profit to about 150 below.
[00:39:43.429]So the $300 per acre spread.
[00:39:46.111]You do see that in the ones that did well,
[00:39:50.865]their yields were generally high.
[00:39:54.034]Higher than the ones that didn't do as well.
[00:39:57.833]But that's only very much a little part of the story.
[00:40:02.315]If you look at farm number nine, 261, farm number 10, 261,
[00:40:09.040]it's the same.
[00:40:10.185]But there's almost a $70 per acre profit difference so,
[00:40:18.859]just making the top yield wasn't the entire answer
[00:40:24.107]to the profitability question
[00:40:25.617]as the extension has been communicating that
[00:40:30.315]for decades now.
[00:40:32.570]Well in our given year, we have very low corn prices,
[00:40:35.715]there was a 20 to 25% price difference
[00:40:39.115]based on when you marketed your grain,
[00:40:41.513]during the time of this competition.
[00:40:43.716]So from about March to the end of November,
[00:40:46.856]when they could market it.
[00:40:48.287]So just that made a huge difference.
[00:40:52.981]And then when some of the differences were,
[00:40:55.175]especially if we left our low corn prices in 2017,
[00:40:58.659]it was really important to keep costs low.
[00:41:02.266]So, this was a year
[00:41:05.792]where you didn't claim any crop insurance money
[00:41:10.018]so that played into that too.
[00:41:14.854]So that was 2017 where definitely
[00:41:18.073]we're continuing to do this
[00:41:21.069]and we're trying to expand to three concurrent competitions,
[00:41:24.857]that was one, just now,
[00:41:26.515]this would be the same as last year
[00:41:28.020]so corn following soybeans on a center pivot.
[00:41:30.844]We want to start a subsurface drip one,
[00:41:33.067]depending on the availability of that installation.
[00:41:36.817]And then another crop, milo.
[00:41:43.754]So with all the things you just saw, there's interaction
[00:41:48.549]with a bunch of different effects going on.
[00:41:51.269]You have different seeding products, seeding rates,
[00:41:56.574]irrigation, nitrogen,
[00:41:57.946]everything is just, it's the combination of all of them.
[00:42:01.976]And so if as a irrigation and fertigation researcher,
[00:42:06.420]I need to isolate some of those irrigation
[00:42:09.345]and fertigation effects.
[00:42:10.990]And so if I have all the hybrid things
[00:42:12.585]going on in the background
[00:42:13.917]that's really hard to do,
[00:42:15.326]and so, we're gonna think of a way
[00:42:17.074]to try to control for that
[00:42:18.474]and be able to glean more
[00:42:22.703]about those particular management decisions.
[00:42:25.465]And of course as growers are using these technologies,
[00:42:28.005]we're using these technologies,
[00:42:30.159]all the ones that we've showed just now,
[00:42:32.536]we wanna be sharing information with the public on those.
[00:42:36.367]And so, we're excited about this,
[00:42:41.122]we think the growers
[00:42:42.643]that participated were very enthusiastic,
[00:42:46.160]we just love the interaction.
[00:42:48.404]This competition drew much larger crowds
[00:42:51.643]to our field day than previously
[00:42:53.942]because part of the effect was just,
[00:42:57.577]growers that were participating in the contest,
[00:43:00.322]they were inviting their neighbors
[00:43:02.008]to come listen to them speak
[00:43:03.259]at the grower panel, so that was all,
[00:43:06.944]all the peer to peer things are happening
[00:43:10.033]and we think are great
[00:43:10.866]and we want to encourage more of that.
[00:43:13.792]We're developing as a research farm, trying to innovate
[00:43:17.612]and push forward in our cropping
[00:43:20.842]and crop management practices too
[00:43:23.453]and so, this has all been very beneficial to that
[00:43:26.592]and we're very thankful for all the university and corporate
[00:43:30.310]and all the other sponsors that have really made this happen
[00:43:33.451]and also just the growers of Nebraska
[00:43:35.381]have just been very supportive.
[00:43:38.558]So, if you are at all interested in this
[00:43:44.025]UNL-TAPS competition, we want to recruit a student,
[00:43:49.014]preferably a PhD student,
[00:43:50.090]but a master's student should work.
[00:43:52.129]So are you fascinated by the research
[00:43:53.960]and extension opportunities of UNL-TAPS?
[00:43:56.796]Will you have obtained a BS or MS degree
[00:43:58.645]by December 2018 at the latest?
[00:44:01.367]Does a career in UNL agricultural research
[00:44:03.805]and extension interest you?
[00:44:05.979]If you answered yes to all three questions above
[00:44:08.182]please email daran.rudnick@unl.edu,
[00:44:11.099]I'm gonna leave that slide up
[00:44:12.896]and that would be the end of my prepared presentation,
[00:44:17.000]thank you so much for your attention.
[00:44:19.234](audience applause)
[00:44:24.526]Alright, thank you Mr. Lo,
[00:44:26.182]so now you guys have a great idea of what's going on
[00:44:28.569]in terms of irrigation
[00:44:29.850]and fertigation, research and extension
[00:44:31.864]out in West Central Nebraska.
[00:44:34.180]Let's open it up for questions, this is on video,
[00:44:36.761]so if you have a question, raise your hand
[00:44:38.224]and I'll be sure to get you to the mic
[00:44:39.544]so we get a recording.
[00:44:43.770]I mean, nice job,
[00:44:45.457]question about the technology.
[00:44:48.635]I don't have to go into specifics
[00:44:49.712]but was there any, like the weather station or the imagery,
[00:44:52.798]that one that the growers preferred
[00:44:54.911]and any of them that they used
[00:44:56.385]to actually make a real time decision,
[00:44:58.257]you talk about that a little bit.
[00:45:00.790]Um, do I need to repeat that question,
[00:45:02.520]that probably was well captured right?
[00:45:04.522]So okay, let me see if I could go back to that slide.
[00:45:10.342]So thank you for that question Trent.
[00:45:15.761]We're trying to do more
[00:45:18.379]in terms of just gathering the feedback
[00:45:20.362]in terms of what did people find most helpful
[00:45:23.186]and what did they use.
[00:45:24.606]So unfortunately I'm not able to at this point
[00:45:27.270]tell you which was more preferred.
[00:45:32.190]I would say that, I can give you
[00:45:34.033]a little bit more background
[00:45:35.019]between the two differences and then.
[00:45:37.640]The FarmersEdge I think is more frequent,
[00:45:40.810]it is RGB only, private satellite, commercial.
[00:45:46.255]AirScout is aerial.
[00:45:48.339]It's a plan that goes over about once every two weeks,
[00:45:51.517]weather dependent.
[00:45:52.980]It has both a DSLR camera and a thermal camera.
[00:45:59.400]So the AirScout people are proud of
[00:46:02.181]their much higher resolution
[00:46:05.968]and they advertise it as a tool for identifying
[00:46:11.107]stress that your crop scout or yourself or your gronomers
[00:46:14.227]can go identify.
[00:46:16.978]Neither are intending their product to be used
[00:46:23.204]at least as I am aware, operationally,
[00:46:25.602]to make frequent decisions such as irrigation.
[00:46:29.819]You definitely don't want something every two weeks
[00:46:33.018]to be the only source of information you use to,
[00:46:35.771]manage irrigation for example.
[00:46:37.009]But it will identify for example,
[00:46:39.409]problems with your pivot and the like
[00:46:42.497]or if you're starting to really lag behind
[00:46:44.750]in terms of water stress
[00:46:45.847]compared to some of your fellow contestants but,
[00:46:51.283]what I did hear about people using a lot,
[00:46:56.627]multi-sensor capacinous probes.
[00:46:59.083]More than one grower I heard from said,
[00:47:03.940]that's the only thing I used to schedule irrigation so,
[00:47:12.343]Daran also used it and he found it pretty helpful so.
[00:47:19.137]Alright, other questions.
[00:47:29.601]I have three questions,
[00:47:30.884]am I coming through okay?
[00:47:33.354]Can you hear me okay?
[00:47:34.754]I can hear you.
[00:47:35.587]Okay, I'll try to speak out.
[00:47:36.422]I'm just not sure I can remember all three questions.
[00:47:38.654]We can do one of them at a time.
[00:47:40.330]Just to say this is
[00:47:41.163]part of your continued PhD exam.
[00:47:44.491]I'll ask questions in order.
[00:47:46.401]Number one is, about half of your participants
[00:47:51.483]have made profits and half didn't.
[00:47:53.483]How did that compare, just off the top your head
[00:47:55.749]about what happened generally in your area,
[00:47:58.655]was it a year where most people made money
[00:48:00.576]and most people did not?
[00:48:02.527]So, to answer that question, we,
[00:48:06.915]I indirectly heard some feedback from local ag lenders.
[00:48:10.572]So I just like, second, third hand information,
[00:48:13.864]but the $300 spread, approximately what we saw,
[00:48:17.622]is representative of conditions
[00:48:19.053]in West Central Nebraska and,
[00:48:24.377]quite a lot of people were taking money
[00:48:28.004]out of their cash reserves this year.
[00:48:30.712]Low corn price, just.
[00:48:33.831]I don't want the person's name
[00:48:35.510]but the people that did the best,
[00:48:37.489]the three top contestants,
[00:48:41.532]can you tell us anything about who they were
[00:48:43.187]or their backgrounds?
[00:48:45.616]Well, I don't know how much I'm supposed to say.
[00:48:51.772]Actually all the results are online.
[00:48:54.048]But I can tell you that grower number 13
[00:49:00.609]is a very good business man.
[00:49:03.068]And the big part of his success,
[00:49:05.499]he didn't get the highest yield, he got a high yield,
[00:49:08.159]he wasn't the most efficient
[00:49:10.130]with his irrigation and nitrogen,
[00:49:11.918]but it was all his marketing.
[00:49:14.252]When he marketed and how he marketed his grain.
[00:49:18.103]And number one, I think is stress treatment,
[00:49:26.486]it's a control, so it's not an actual grower.
[00:49:29.754]And number nine is the UNL team.
[00:49:32.488]Very good, thank you.
[00:49:40.923]I also have a question with the TAPS program,
[00:49:42.507]that's just that for future years,
[00:49:44.232]are you gonna use the same plots
[00:49:46.415]as the plots that you used before
[00:49:47.494]and if you do, how will you control for the fact
[00:49:49.912]that you're starting from a different place
[00:49:52.155]and those different locations.
[00:49:55.026]Wonderful question.
[00:49:58.097]So you can see here that, there are corn following soybeans,
[00:50:03.472]so it needs to be on soybean ground then from 2017.
[00:50:07.141]So we have soybean ground that we've allocated
[00:50:10.595]for this competition to go into.
[00:50:12.755]So it's going into a fresh un-treatment affected ground
[00:50:17.523]and so, that drastically increases the land requirement
[00:50:22.257]but that's what we've been doing.
[00:50:25.020]We create undisturbed soybean ground
[00:50:28.838]to have corn experiments but yes, thanks for you question.
[00:50:33.318]Did I answer all of Dr. Jolie's, that was okay.
[00:50:43.779]Hello Him, thank your for this presentation
[00:50:46.582]and I was really fascinated by the UNL-TAPS program.
[00:50:51.305]I'm gonna have to tell Daran that.
[00:50:54.567]Sure.
[00:50:55.400]So my question is that,
[00:50:57.107]I was just curious about the plot size
[00:51:00.906]and whether the different, how uniform the soil types were
[00:51:05.721]and whether that was being considered
[00:51:07.904]when the plots were being distributed to different teams
[00:51:12.000]so that might be a point of different yields for them.
[00:51:17.182]Thank you.
[00:51:18.357]Thank you for your question Sundu.
[00:51:21.224]This is our actual plot map.
[00:51:25.653]We noted that,
[00:51:31.036]that the major source of soil variability
[00:51:33.331]as I understand in this field
[00:51:35.208]is due to past management history.
[00:51:37.323]This is a field that used to be many fields.
[00:51:40.261]So, seems like much of the variability is this direction,
[00:51:47.027]so we try to block it that way.
[00:51:48.733]Originally it would probably be considered
[00:51:50.712]the same soil type, this olivio terris loamy soil,
[00:51:57.711]typically fall under the Cozad series.
[00:52:00.899]So, this would be a randomized complete block design,
[00:52:06.843]15 treatments here,
[00:52:08.531]15 plots here, 15 plots here and 15 plots here.
[00:52:11.466]So, that is, the variability is definitely something
[00:52:20.004]that we're keeping very close attention to.
[00:52:25.566]We would think that it would be difficult to do this well
[00:52:30.108]with fewer than three based on what we're seeing so,
[00:52:34.140]obviously more would be better but,
[00:52:36.590]there is a lot of pressure from stakeholders
[00:52:39.860]wanting more contestants and more contestants
[00:52:41.921]and more contestants
[00:52:42.977]and that's a difficult balance but, thank you.
[00:52:53.056]The folks in Israel
[00:52:54.254]are coming up with different kinds of monitoring devices
[00:52:58.187]and one of these is, I think it's called Crop X,
[00:53:02.108]it's like a little auger that you screw into the ground
[00:53:05.745]and at various places
[00:53:07.632]there are electrical conductivity detectors
[00:53:10.903]that sends the information up to the cloud,
[00:53:12.851]that's one of them.
[00:53:14.694]The other one that they're talking about
[00:53:16.602]is called a dendrometer, which measures the shrinking
[00:53:20.301]and swelling of the stock, corn stock.
[00:53:24.150]As the time goes on and the water stress develops so.
[00:53:28.709]Do you have any experience with those
[00:53:30.080]or any thoughts about how those operate?
[00:53:33.188]Thank you for your question.
[00:53:35.525]I have not used the Crop X,
[00:53:39.710]the electrical conductivity measurement.
[00:53:43.489]I would think that especially in their climatic environment,
[00:53:47.745]would be much related to salinity management,
[00:53:52.736]that's not really a concern where we are.
[00:53:55.073]Some people have used electrical conductivity measurements
[00:53:57.542]to infer about nutrient movement in the soil profile.
[00:54:02.256]There's actually been research
[00:54:03.089]in that from Dr. Jose Pero in the 2000s but,
[00:54:09.975]we have not looked at that specifically
[00:54:14.876]for the nutrient movement.
[00:54:17.842]We would like to if we have the,
[00:54:19.992]if we do get the sensors to do it
[00:54:23.051]so the short answer to that first part is no.
[00:54:27.491]Dendrometers, we have been approached
[00:54:30.531]about middle of the season
[00:54:32.034]by a certain, I think it's an Israeli company
[00:54:35.406]by the name of FiTech.
[00:54:38.208]They were selling these,
[00:54:41.482]I think micrometer resolution dendrometers
[00:54:46.024]that pinch the corn stock.
[00:54:49.050]I was not involved with the particular presentation
[00:54:51.205]they gave to Dr. Rudnick about well or not work they were
[00:54:55.155]but I know from reading the literature
[00:54:57.797]that they have been used to correlate with water stress
[00:55:01.189]so we do have a little bit of data,
[00:55:03.863]unfortunately there were a lot of mice
[00:55:05.698]chewing wire this past year
[00:55:09.296]and so I'm not sure how complete that dataset we did,
[00:55:14.346]we just had a few of them
[00:55:16.489]in some few plots and so, just really relatively pilot data,
[00:55:20.422]I've not have access and analyzed it but,
[00:55:23.764]we'd be interested in doing so,
[00:55:25.626]as that has been proposed as a way to schedule irrigation
[00:55:29.948]and monitor water stress so,
[00:55:31.329]thank you for your question.
[00:55:33.077]Alright we're about out of time
[00:55:34.113]but we could do one more question,
[00:55:35.492]does anyone have a last question?
[00:55:41.974]Interesting talk I mean,
[00:55:44.495]one question I have is with this layout
[00:55:48.001]of the information you got
[00:55:50.053]from the growers for decision making,
[00:55:53.533]did the decision making on the part of the growers
[00:55:57.800]was also variable across the plots they were assigned
[00:56:02.203]and what did you recognize that as a variable that
[00:56:08.368]part of putting out recommendations to you
[00:56:12.511]are made it across the plots or they considered
[00:56:15.581]all their collection of plots as a single unit
[00:56:18.039]and then carried out recommendations.
[00:56:21.363]Thank you for your question Mipel.
[00:56:22.925]So, this was simulating flat rate management
[00:56:29.354]for 3000 acres.
[00:56:31.002]So we only took one set of instructions.
[00:56:35.602]So for example, if farm 15 made a decision,
[00:56:40.055]it would be applied to all three farm 15 plots
[00:56:43.384]exactly the same.
[00:56:46.280]So the assumption is that this would kind of represent
[00:56:50.599]a farm where there is some variability
[00:56:52.112]but the same management was applied.
[00:56:54.518]Should or, for some of the data that was gathered,
[00:57:02.616]well for the information that was gathered
[00:57:04.436]for them to manage their information,
[00:57:06.833]they got from all the plots.
[00:57:09.260]So the satellite imagery, air imagery, they got everything.
[00:57:11.860]But for soil moisture sensors
[00:57:13.313]there's only one rep so,
[00:57:15.475]it was all in block B for the soil moisture sensors.
[00:57:19.674]But, now that's representative of what unfortunately happens
[00:57:22.893]with some of these multi-sensor capacitor probes,
[00:57:25.078]there's one in the whole field.
[00:57:27.191]But in terms of how we got the information
[00:57:30.491]to evaluate who won, yield was combined three plots.
[00:57:35.530]Our estimation of its,
[00:57:38.699]the evapo-transpiration of the plots' nitrogen uptake,
[00:57:43.047]plant samples from all three plots,
[00:57:44.732]grain samples from all three plots, so,
[00:57:48.757]a lot of work in November.
[00:57:54.201]Thank you.
[00:57:55.215]Alright well this concludes this week's seminar,
[00:57:57.006]please join me in thanking Mr. Lo.
[00:57:59.322](audience applause)

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Irrigation and Fertigation Management

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