The Muster- Graham Butcher: Drainage Options

Graham Butcher looks at farm drainage.

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Episode Transcript

Speaker 1 (00:10):
Welcome back to the muster on Haka Nui f I'm consultant.
Graham Butcher joins us in studio. Good afternoon, afternoon, Andy,
Brian Adams, you are fair oh sort of. Well that's
the music theme. He's coming to christ Church in March,
and songs from the eighties, well, the argum and likes

(00:31):
of Summer of sixty nine, just anthems at a timeless too.

Speaker 2 (00:34):
Well, good music will always have a renaissance. You go
right back to Beethoven and what have you have many
renaissances had, so good music will always be there.

Speaker 1 (00:43):
Yeah, very good points. Another good point today too, we're
talking about drainage.

Speaker 2 (00:47):
Yeah, drainage. It's an issue that comes up, I suppose
all the time. I've had a couple of very wet springs,
the saws are pretty wet stool, So I just I'm
just dealing with a large farm at the moment. Just
looking at the post bullies of drainage. So I just
did a bit of homework on to what the effects
were and what it costs, effects and all that sort

(01:08):
of things. So I just sort of make a few
comments about that. So water logged soils have quite a
bad effect on pasture growth. The oxygen levels go down,
there's no root growth. Nitrogen fixation stops decomposition of organic
matter carries on, and that actually lowers the oxygen levels
further and increases co two. Wet soils are cold, slow

(01:33):
to get away on the spring. There's a whole lot
of things that happen. Wet Soils also can produce toxin
zon and manganese and hydrogen sulfide, which is one I
hadn't heard of before. They're all toxic to roots. So
wet soils are bad news all around, not only for
pasture growth, but for pugging damage and what have you.
And that has a lot of pretty serious effects too.
Recovery from water logging. It's mediated by biological activity root

(01:56):
growth worms to get the macroporosity going and what have you.
It can take six to twenty weeks to actually fix.
So you know, I've seen pugged badly damaged brakes and
the effect to me seems longer than twenty weeks. If
it happens bad, you can you can pick the brakes
that were barely pugged past to cover. If you're destroying

(02:19):
past to cover with pugging and what have you ten
weeks minimum to recover from that, and that's un till
the numbers can't getting back to where they should be
and surface roughness could take four months to fix that.
So a whole lot of bad things about water logging.
So if we have a brief look at the cost
to fix water logging, So we'll take an example of

(02:42):
a reasonably intensive drainage of soils. I mean, drain call
costs about a thousand dollars slotted one hundred meters coil,
probably cost the saying to install it put it in,
So you're talking two thousand dollars per coil. If you've
got a program of eighty meter spacing for your drain
call to provide your outlets for moles, and you've got

(03:02):
a three meter spacing for moles, you're talking just under
three thousand dollars a heck there to do that, which
is you know, a significant sum of money. But that's
quite an intensive program. If you go to a fifty
meter spacing and a two meter mole with that's even
more intense. If you're talking just under four grand, just sorry,

(03:22):
just under five grand to do that, So we're talking
quite big money. So you've got to consider is there
a return. You know, we're talking pretty significant impacts on
pasture growth here. So what I did is take a
thirty percent dig decrease in past your growth for six months.
That's possibly what happens in the field. And if we've

(03:44):
got a ten ton dry matter planting, we're losing fifteen
hundred kilograms of dry matter per annum. We can use
about eighty five percent of that had it been there
in the first place. Of course, twelve hundred and seventy
five kilograms of dry matter that we have lost and
on one hundred and thirty five percent sheep flock no
hog itt mating, that's worth about twenty nine cents a

(04:07):
kilogram dry matter, which is an income of three hundred
and seventy dollars. If we go back to the just
under three thousand drainage scenario, we could borrow that at
six and a half percent over fifteen years three hundred
dollars for an them. So it pays. But that's quite
an intensive sort of drainage program.

Speaker 1 (04:30):
And you've got the tile versus an overflow coil debate
as well. Your head, the price comes in, like you.

Speaker 2 (04:35):
Say, yeah, but installing tiles is a bit slower than
putting overflow and you're just done rolling She's there.

Speaker 1 (04:41):
Have you done a few days behind the clevelandbe old Cleveland,
going in there and putting in the trenches and you've
got the tiles picking them up in a couple of
days doing that. Jesus. You know, challuses are after you've done.

Speaker 2 (04:53):
That, done it occasion, but not be as the time.
So I'll take your word for it. And yeah, so
you know, one hundred and thirty five percent, no hobgit mating.
It pays on your probably your better class of land
to do relatively intensive draining. Now there's a whole lot
of degrees you might just go in and put an
overflow into your wet spots and what have you. The

(05:14):
flat of the land you've got that you've got to
be more precise about how you go about doing your drainage.
I mean, if you haven't got much fool the outlets
from moles has got to be a shorter distance because
in a flat situation, water sits in the moles and
that just breaks down the mole pretty quickly. So you

(05:35):
also got to consider your getting around the farm. Wet soils,
weed and grass rushes, all that sort of thing. Wet soils,
your newer pasture species, your eye grasses you' putting them
in won't last as long. So there's another cost there
as well. So there's a whole lot of benefits that
stack up from having well trained soils. So when you're

(05:58):
looking at farm development, past your development, you've got to
think about fertilizer, you've got to think about your past,
your varieties, got to think about fencing, and you've also
got to think about drainage. It's got to it's got
to be back on the table now, drainage. The last
several years in farming, the money just hasn't been there
to do it because it is a relatively expensive one

(06:19):
to do.

Speaker 1 (06:19):
Hasn't the terminology around drainage fascinating? I mean it's one
of those things, Yeah, you talk about mules, you talk
about full it's intriguing. It's certainly something that's just cosential.

Speaker 2 (06:30):
Rural well, it's it's you know, a good a good
bigger contractor who's got a bit of field experience can
can be pretty good in doing your drainage. Put it,
you know, draining those wheat patches, all that sort of thing.
Though they're pretty good at that. When it comes to
moles different kettle of fish, you've got to know where
the clay levels are and your distances and your falls

(06:50):
and all that sort of thing. So it becomes a
bit more technical to do a good mauling system. It
pays to do it properly because if you don't, it'll
break down in a couple of years. So you've got
to have someone who knows what they're doing. But it's
got to be pot back on the table and jump
up your list of priorities of it because there have
money there now to do it and the benefits are there.

Speaker 1 (07:11):
Get on your Graham and enjoy the afternoon Graham Butcher
fun consultant. The relevance of drainage, that's for sure. Max
Mcallum's up next. You're listening to the Muster