Soil Sample and fert rates

[ado089]

Well I got a pretty resounding negative
response in the VRT discussion. With
that said how many are soil sampling?
Are you achieving your target yields vs
fertility applied? Do you know your
Benchmarks for bu/lb of N or inch of
rain? If you are using recipes how do
know you're getting the most out of your
fert $?

[SASKFARMER3]

Soil tests are done last Thursday. Same fields for
12 years. Chart compare, yields etc GPS last 7.
Variable works great for guys tat don't know their
fields yields etc etc. one guy locally use to give
every single field 120 n phos at 50 etc. variable
and a coach found out can go with 80 to 100 28
to 60 phos. Saved him money. Big time.

[freewheat]

I often hit my targets on untested land,
sure. I actually trust my gut more than
soil tests often, because of knowing
individual fields, and once one gets his
yields accurately, one has a very good
idea of what was removed.

[fjlip]

How much N required after 20 bu crop?

[freewheat]

20 bushel crop of canola? lol, I thought
we were friends, and you go and throw me a
curve ball. Need to know the crop type,
and how much residue there was. You bring
up a good point, this year with 50 bushel
plant matter, and 20 bushel yields, my
theory is not as accurate as it could be.

[fjlip]

This was hailed and rained on hard several times...short thin, plant matter for about 20 bu.
I'd guess 50lbs max taken, unless 20" of rain washed the N. Weeds were healthy.
But darn little soaked in from the hard rains, most ran off drowning low spots.

[mbratrud]

Soil Testing tried tested and proved on our farm.

The past few years we have been Variable Rating as well.

We used Crop Pro consulting from Naicam to Veris our land, then we ground truthed and worked with them to develope 5 zones on our fields.

Each zone is then sampled by my wife and we use Western Ag Labs forecast model to write the perscription. This allows us to model water scenarios for each zone.

This year was the first year we really got to test it out (because we didn't flood) we definately seen a difference in the zones for N availabily from 10lbs available to over 60lbs available.

By having that knowledge we were able to vary our Fert and Seeding rates allowing us to acheive yield targets even out our maturity. At the end of the day saved about $30K on our farm without sacrificing yeild.

Every year is going to be different and just because we saved this year does not mean the same will be true in the future but its one more peice of information to make good decisions on including crop planning.

For example Guys that put soybeans on chemfallow had poorer yield results compared to stubble in our area and the theory is high N delayed nodulation. had they known that would they have changed field choices? On our farm we did.

Are soil analysis gosphel? No but its information and how you use it is important.

[ado089]

I use conventional sampling to identify
any hidden yield drags but on a yearly
basis I've been more satisfied with
Western, it took a couple of years to
hone the results to my land but I've
found them to be quite accurate. The
downside I find with conventional tests
and recommendations is that they do not
take into account the fact that to get a
50 bu/ac crop (wheat or canola) you need
some pretty special conditions. Those
conditions also tend to result in
greater nutrient cycling. Their program
takes that into account in the recommendation whereas a conventional recommendation would simply call for
more N to get that yield.