I'm going to try to be quick here.
So you don't really have to look at the drought monitor
to know that we're in a bad situation.
We had a really dry growing season last year,
and things aren't looking so great for next year.
We're hoping that we get a good snowpack,
but it's very likely that we could
go into to another drought in 2021.
So I want to just share quickly some of the things
that we're working on in terms of water management
in the state.
And today I want to talk about just five questions.
And they are, can advance irrigation systems save water?
What impacts will partial irrigation have?
Can alfalfa genetics help mitigate water stress?
Do new sprinklers affect yield water use?
And can we cut back 10% on our rates?
So question number 1, can we apply less irrigation
and maintain yield with some advanced irrigation systems?
Many of you are probably familiar with these.
On the left there you'll see the MESA.
That's a mid elevation sprinkler.
That's what's on most of our pivots in this region.
However, there's some newer technologies.
Or lots of different low elevation sprinkler types.
I've Listed three there, LESA, LEPA, LENA.
And then more recently, mobile drip irrigation
has been developed and marketed for pivots.
And so the question here is can these advanced irrigation
systems save water?
To answer that, we've conducted a series of trials,
different parts of the state, different types of trials,
and I'm going to share just a few of the results for alfalfa.
This started back in 2016.
Neil Allen, our irrigation specialist
started doing some work with LEPA, one of the low elevation
systems, and he put LEPA on three pivots that had alfalfa.
And they put it on at the same rate
as the MESA or mid elevation.
And what they found is that LEPA, in all cases,
it maintained yield and in some cases even
improved yield a little bit, probably because of better
uniformity of irrigation.
But we still couldn't answer the question,
can we cut back on irrigation rates
if the irrigation system is more efficient?
And so in 2018 we started some additional work.
This is some research from Cedar City where we conducted trials
over three years with LEPA and mobile drip irrigation, MDI,
and what I'm showing here is everything
relative to mid elevation sprinklers, MESA.
So on the left there you'll see the mid elevation is
all at 100%, and then you'll quickly
see that everything else is lower than 100%.
And what that means is that in most cases
we could not maintain yield with these other systems,
and especially when we reduced irrigation rates.
So only in one year, 2018, did we maintain yield with LEPA,
but that was at the same rate.
It's a 400% rate.
And then in these other years we saw reductions in yield
when we applied less water
And we also have started doing some work in Logan at a site
here.
This site has a linear instead of a center
pivot, so I think we're getting a little bit better control,
and this is also an early or a young alfalfa stand,
this is a first year alfalfa stand.
And in this first year alfalfa stand we had two cuts in 2020,
and we saw that almost all of the systems
maintained yield, everything except the mobile drip
irrigation at a reduced rate.
So quite encouraging for Logan, but the point was that
sometimes it helps and sometimes it doesn't.
OK.
And that same study in Logan, we're
also looking at some impacts of partial irrigation.
So question number 2.
What impacts will partial irrigation have?
So our treatments in this study is
to look at a full irrigation.
And we had a 25% reduction, a 50% reduction in irrigation
rate, and then a same 50% reduction but we
tried to target it.
We put on more water near the beginning of the cutting,
and then tapered it off and put less
as we got close to harvest.
And the full irrigation for those two cuts
was about 13 and 1/2 inches.
So here's what we found.
When we reduced the water by 25%, we saw about 20%
less alfalfa yield.
When we reduced it by 50%, we saw about 30%
less alfalfa yield.
That 50% targeted irrigation, it was quite different
in the first and the second cut.
So in the first cut we saw a pretty significant loss,
similar to the flat 50% reduction,
but in the second cutting, it wasn't that bad.
It only slightly reduced yield.
So this work is really early, preliminary,
but it indicates that there may be some potential
to try to target reductions in irrigation rates
to really lessen the impacts of partial irrigation.
Question 3.
Can alfalfa genetics help mitigate water stress?
So this is the same study in Logan,
we're looking at different crop genetics.
So we have a conventional alfalfa variety,
and then we're looking at a variety, Ladak II.
Many of you are probably familiar with Ladak II.
Both of these had a fall dormancy three, non-Roundup
Ready.
And so far, again, this is just a young stand, two cuttings,
but we're not seeing really any interactions with water.
We did see that the conventional variety yielded better
than Ladak in both cuts, but there
was no interaction with water.
Ladak didn't handle water stress any differently
than the conventional variety.
So not much promise here yet, but we're
hoping that with time we see more interactions with water.
Question 4.
Do new sprinklers affect yield water use?
So this project was on 12 farms in Central Utah.
We pitched 12 pivots with the range in age of sprinklers.
So this is the nozzles and the regulators.
And we came in and we put on brand new sprinklers, brand
new regulators, we wanted to see what the impact was.
So in 2019, we collected data off of 37 alfalfa cuts,
and that was on 12 farms, and we saw that about 15%
of the time, there was a benefit to having brand new sprinklers.
A small percentage of the time there was a negative effect,
and then most of the time there was
no impact of new sprinklers.
Results were quite similar in 2020.
We had 19 cuts on eight farms, and about 25% of the time
we saw an advantage to having brand new sprinklers.
This is likely related to whether.
2020 was a lot drier, much drier than 2019,
and so that's probably why we saw a little more benefit
to new sprinklers.
Question 5.
Can we cut back our irrigation rates by 10%?
So on these same 12 farms, we took
a portion of the span, one span on the pivot,
and we cut back the rates by 10%.
And in 2019 we saw about 10% of the time
it impacted or it reduced alfalfa yield.
That was it.
So that was quite encouraging.
In 2020, similar but to a little bit larger extent.
About 25% of the time, 25% of the cuts,
we saw a yield reduction due to a reduction in the irrigation
rate.
I do want to point out that both of these back here
with the new sprinklers and with the rate reductions,
they didn't happen on the same farms and the same cuts
consistently.
They were quite random.
It was a cut here at this farm, and a cut there at that farm.
It didn't have consistent negative or positive effects
on a particular farm.
OK.
So in summary, can advance systems save water?
Sometimes.
We're still trying to pinpoint when and where,
but it's quite apparent that it really
depends on your site, and the conditions that your site.
So be careful.
If you're looking at these advanced systems,
make sure you do a good job at assessing
whether it's going to work.
What impacts will partial irrigation have?
If you need to cut it back--
we don't like to do partial irrigation,
but sometimes we're forced to.
And so if we have to cut back by 25%,
you should expect maybe about a 20% yield loss.
So far we're not seeing much impact of the alfalfa genetics
on helping to mitigate water stress,
but hoping that changes.
Hoping there's some things we can do with genetics
to help deal with water stress.
Do new sprinklers affect yield/water use?
We've really seen minor effects so far.
A few cuts at random farms, but no consistent positive effects
of new equipment.
This doesn't mean you should leave your sprinklers
on your pivot for 20 years, but think carefully
about when you replace those sprinklers.
And finally, can we cut back 10% on rates?
I think the answer is yes in many cases.
So in some cuts on some fields we may see reductions,
but we're not seeing it across the board.
So if you need to cut back on water,
this might be a way, a lower risk way to save some water.
It's just to cut back a little bit.
OK.
Thank you.