Irrigation Depletion

Uh, so, so this is a corn alfalfa
pivot, and a corn pivot.

And then one of the objectives is to
see if corn triticale mix produces more

and uses the same or less water than
alfalfa, so one's a two crop system,

and then of course, alfalfa being the
perennial crop um, just take note.

This, these pivots out in this area,
they've only been in for one year now,

so that entered into play in some of
our results, but we went out uh,

the day after they planted, or maybe
a couple of days after they planted.

And we put in soil moisture sensors. Uh,
this corn was planted on 22-inch rows.

There was no furrows and
beds, so it's just, the furrow

is where the corn is planted.
We protected the seed by where we

were doing digging by putting
a half pipe over them,

and then we put our data logger
about 10 feet or more from where

the soil moisture sensors go in, and you
can see on the, the right side of the

screen there it's quite shallow
soil, and very gravelly and

even the shallow soil is quite sandy.
Um, they had planted triticale in

September, and then, they harvested
it in uh, in May, and then they planted

around the first of June they harvested
about near the last half of May,

and um, going back to what Merrell has
done they took uh just out of curiosity,

they took uh, span three and
five and left it in the stubble,

and planted the corn into the stubble.
And then, the rest of it they

conventionally tilled it but a shallow
tillage, but I took this picture

the day that uh, we were there, so this
is a couple days after they planted,

and that 's the same wheel track there.
But you can see the water ponding

where they have filled the soil, and no
ponding where they have not filled

the soil, so I think that's um, a pretty
good indication of this particular

location where the soil was brand
new, had very little organic matter

in it, infiltration rate was much higher
with that, and we had a problem

as we got into the season.
I'm just showing mostly pictures

here, but uh, when we went back down
a few times during the season we

could see that there's a lot of
non-uniformity in the corn, and it's new

ground it fertilizes all the same,
treated all the same, killed it all the

same, but strictly a water issue.
And um, I don't know if you can see

here, but see how that water's
in that furrow, and it- anywhere

we had a slope, we had a problem
with the water running away,

so we had some areas that were
decent where our sensors were,

and some that were poor. Um,
here's one that's kind of medium.

One that received the same amount
of water, 30-inch spacing, brand new

pivot package, applying 850 gallons per
minute in this pip pivot, um, so when

I got back from that from one of those
trips, I, I pulled up and looked at NDVI

which is normalized difference vegetative
index, and um, from sentinel

to satellite, so it's about a 10 meter
pixel, but you can see you know

the day they planted it uh, the strips
that were no-till, and then you can see

that as we progress through
the season it's a little hard to tell,

but I've got some, some satellite
images, I mean some drone images

that show a little better, but you can
see the non-uniformity in the field,

and I would, most our sensors were
probably about two-thirds the way out

of the field, and we're
comparing the alfalfa field.

This field is much steeper, uh, so far
as slope, but it's been in about 15

to 20 years, and they have no runoff.
You can see we've got runoff coming off

of this field in a couple of locations.
It doesn't go very far in that sandy soil,

but we still had runoff,
and non-uniformity.

So um, and then here's when we
went and took our sensors out

which is the day before they harvested
it, so here' s our three sensors.

One in very short corn
that didn't get much water.

And then we had one where the corn
was I don't know eight to ten feet tall,

and then, one where the corn was
you know six or seven feet tall.

Josh there's about six feet four
inches tall pretty, pretty tall guy.

And here's the non-uniformity
issue that that we had, and we had-,

this farmer has a hundred
pivots approximately.

And we ended up getting one
that wasn't very uniform.

All the pivot, other pivots in this area
is uniform, and we think that's because

of the um, just the water moving
around after it hits the ground.

Just a few more pictures.
And here's the yield harvest.

They had two choppers in there.
This is all for silage, had two choppers,

and I think each had a different
yield scale because every other row is

a little different, and I think
that's because of the combines,

but you can still see the
non-uniformity in that field.

And here's, we went in with uh, Aggie Air
which has like a six centimeter, and

I put three different images.
Here's the aerial image of that field.

The cornfield taken August 10th, and
here's the NDVI, so we still got that

non-uniformity, and then here's the
thermal temperature and thermal is

important because as the water
evaporates it cools the crops, so um, the

darker color is the highest evaporation,
and these lighter colors are less

evaporation and of course out here in
the desert, there's not any evaporation.

It's just really dry there. Um,
the sandy soils, and this is down to

the last sensor was 48 inches, and so
you know we went a little below that with

the water it's representing, but
uh, we had eight sensors in.

Kind of at the shallow one's we went
in between the rows and underneath

the rows and that's very, very
dry in all of the sites, um, so they

harvested the end of September.
A couple of weeks later they

planted triticale in between.
They put a manure compost on it,

so pretty much every load of silages
that went out a load of manure came

back probably about 12 or 15 miles from
their dairy, and um, so they're trying

to build that soil up, but we went into
the third span, so where the application

rate is lower, and we think we'll so far
things are looking pretty good there.

We haven't seen any runoff in the
few irrigations that they have given.

Um, I should point out that the total
irrigation amount during planning the

harvest was 24 inches, and they
had 2.8 inches pre-irrigation, and so

27.6 inches total irrigation, and that's
pretty much the water that they

used because that's out in the desert,
and there's really no precipitation.

Um, this is just taken last
month, and this is triticale.

I just went down there to check
on things because I stopped

getting data from a few things.
Triticale is looking fine.

Um, the alfalfa, they put cattle in it,
and so that's why I wasn't getting data.

They messed up my sensor, so I got
those secure now, but the alfalfa

does have a 90 inch spacing versus
a 30, so I think that might be part of

the reason, and our sensors are
all out here, and this is a conduit

that goes back to the pivot track, so
we don't go in and harvest it by hand.

We don't need to go there ever.
The sensors are just there,

and they farm over them.
And that's the uniformity

of the alfalfa field versus
the corn, so I, I think that's-