Variable Rate Fert

[ado089]

Hi folks,
I've been doing variable rate on the
farm for a couple of years now with
pretty good results, $15-40/ac benefit.
As a result I've decided to take what
I've learnt and try to offer it to
others. The management zones I've been
creating are based on soil texture and
water flow modeling, essentially a water
orientated system matching nutrient
application with projected available
water. I guess I'm curious what others
are seeing from their VR work to get an
idea of what has been working and what
you feel are the downsides or pitfalls
or the system you are currently using.

[farmaholic]

ado: you the only one ding variable rate?

[craig]

I like your idea of trying to determine available water as an important part of the equation. I'm in a higher rainfall area and we are having issues on transition areas where extra moisture has seemed to give us a fertility boost. If we don't account for that we have lodging issues. If your in a drier area then your strategy might be entirely different. Have been in VR for probably 7 or 8 years and we continue to try to better understand the system and how to make it work better on our farm.

[gustgd]

What I learned from one year of VR fertilization. If
you spend a bunch of money on technology and
prescriptions, don't forget to account for weather.
Kill the weeds I they are present. Spray for
disease if conditions warrant. Watch for bugs.
Manage your rotation.
Timing is very important.
I guess what I'm trying to say is get your
agronomy perfect before investing in VR. It's a
later step not a starting place.

[SASKFARMER3]

gustd good point. We did variable rate
back in 1986 to 1992 in the dry years did
get some bonus but not worth the time.
Went back to old system of work the land
you have to the best of your ability
agronomy wise. Watch the weather and in
the end youll come out ahead. Its a end
point if you have every thing working on
your farm. Every thing.

[ado089]

SF3, you sound like you've been to an
agri-trend meeting or two. What I see
out there is guys putting on more inputs
than ever because their neighbor is,
their over priced agronomist tells them
to, their retailer tells them to, the
commercials tell them to, ect. all the
while the while yields stay the same or
maybe see small bumps. I use VR to push
yield without increasing cost and/or to
free up some costs to allocate that
$7/ac fert saving to a shot of Quilt and
copper or to kick in some releaf to give
those delicate canola seedlings a boost
through the flea beetles and rain.
Nutrient response curves are not linear
and alot of land is getting fertilized
beyond its economic benefit once we
start applying N beyond 90lbs/ac.

One example I have is a split field of
Canola, flat rate 90, VR avg rate of 67,
yield was identical, that savings
allowed me to use ESN for the same price
and gain 8bu/ac over the neighbor across
the fence who used the same fertility
program with NH3 planted the same day.

[saskcanfarmer]

Ado - What do you say to a guy like me?Inputs are there, fungy, up to date paralink drill, micros etc etc. Two years in a row we have set up half sections, different half sections. We had 8 reps on each. 4 with VR 4 with standard practices determined by soil tests and past expriences/field history. Both years the non VR strips OUTYIELDED the VR enough that it WASN'T ECONOMICAL to VR.

[ado089]

Was there variability there to start
with? Lodging? Maturity issues? Alot of
land it makes no sense to do it on at
this time. With that said, I've found
the weak part of most VR systems to be
the agronomist and not the maps or the
field. I match mine up with Western ag
labs PRS, I've found it to be
significantly better at indicating the
productive difference from zone to zone.
That aside if you are soil sampling at
all I think it makes alot of sense to
create some sort of zone maps to at
least ensure you are sampling from
locations that most represent the field.

[cropduster]

Interesting discussion here!!Variations in agronomy are a great quest. Anybody care to weigh in with info on the McCrae approach??Calcium/sulphate combos surface or seed applied. Seems like quite the rage in some parts of Ab. Don`t know if application based on variable soil maps or not. Good sales or reality????

[ado089]

Calcium sulfate, or gypsum is used as a
pH amendment, or a floculant to dislodge
phosphate from sodium. It has merit in
areas with photos extremes and most
certainly would be something that makes
sense as a VR application. To affect a
change application rates need to quite
high. Many areas in black soil and peat
region can have yield impacting pH
variations.