Soil samples...

[helmsdale]

Soil testing has more than paid for itself around my operation...

On year's where we get skunked on moisture, it's been astounding to see what sort of nutrients are left over for the following year. Fert bill can often get cut by 1/3 to 1/2. After a banner year, it's equally astounding to see what little is left.

Have also gps'd every sample point in every field, so results year to year are directly comparable. Has been nice to track OM, EC, and PH changes.

[grassfarmer]

Grassy, that almost seems hard to believe but I guess those first two years was alot of nutrient cycling but this year's 9 tonnes taken off and no call for nutrients next year is what is surprising me. Were you intercropping with a legume that you forgot to mention?

Yeah, it surprised me too. No legume, only corn. The physical transformation in the soil is remarkable - from dead concrete like clay to nice mellow stuff full of worms. Organic matter went from 3.4 to 4.3 in 3 years too. We haven'd used glyphosate on it as we seek out good non-GMO corn varieties but the previous farmers used glyphosate and NH3 regularly in their wheat/canola rotations.

[bigzee]

You have to take soil testing with a “grain of salt”. Firstly, like anything you have to believe what you are doing is not a waste of money. I test for the
most part of every year. In 16 we pulled off massive yields, like most. The tests showed very little nutrients left which they should have. So in 17 pumped the ground full very dry conditions, tested results shows very high levels of everything. Nitrogen numbers seemed a little fictitious so had some fields retested, results came back a little lower but still very high .. over 100 lbs available.
Was happy to have tested or else I would have put down a lot that wasn’t needed.
Most guys don’t soil test they put down their regular amounts and go. Phos is the one that’s tricky.
Fert prices are through the roof, commodity prices are crap, be interesting to see if there will be guys cutting back and changing rotations.

[Guest]

Got my first ever positive surprise from a soil test this fall. Grew and grazed corn 2 years running with 80lbs N each year. Same field this year we grew corn again without any fertilizer as we missed the window to get it on then it was so dry it wouldn't have helped. Silaged about 9 ton/acre and when we tested I was assuming it would be severely depleted. Lo and behold it came back showing 143lbs N and the P and K were both very high too. Recommendation for growing a 15 ton corn silage crop next year was zero inputs. Money saved on this field would pay for many years of soil testing.

I would re take that one
we haven't done many over the years , because we don't follow them , but decided we would check them all this year . one came back with 70 lbs on N . told them to re take it and came back at 15 lbs N

[farmaholic]

Kinda a crap year in 2015, a bin buster in 2016, another kinda crappy one in 2017 and a respectible 2018. Wheat most of those years was almost always the best, it must be mining out the nutrients.

N is dismal in my fields. How much mineralization(?) can I count on? There is enough residue on some fields and has been for a while, I would think it has to be cycling for years already. Residue doesn't build up on flax years, and not much in lentils, but that may only be 1 out of 4 or 5 years in the rotation. You may think peas don't leave much but it is generally smashed to smithereens....unless the crop suffered field wide root rot inhibiting a healthy crop stand.

So what's the deal on the Phos results in the opening post of this thread?

This us what the report states:

Phosphorus-P ppm
Bicarb- X value
Bray-P1- X value

No where in the results section is there a lbs/ac value...only in the recommendation section do the "prescribe" X lbs/acre of P for target yields.

[SASKFARMER3]

We always take soil samples.

Out of total farm, I base our samples on Blocks of Land and Pinpoint tests. GPS locations same area each year.

I also base these same fields on Soil Class and Rain amounts long-term trends.

Basically 12 fields out of the total. Same each year.

Then if we have any fields that something didn't look right we do those fields.

Had one this year than last year produced way less on HRS than all others. I found issues and changed up some Fert and it was one of the best this year. It had issues with being mined for more years before we bought it than most in that area. Seed burn seed burn seed burn very little fert.

Pig shit is also an extra.

Then I get them to do high yield projections.

HRS 78
Canola 62
Barley 110
Peas 75

Look at results and costs etc.

Then get them to redo a scenario with less projected summer rain.

HRS 50
Canola 40
Barley 80
Peas 50

Compare the two and come up with a plan and then if it's a decent spring we just up or down.

I do tissue tests in June to see if I'm doing ok with my projections.

Funny pig shit took a farm that was the only fert. three times since broke according to the previous owner and made it in 10 years one of the better around.

It seems to work as I can keep up or pass the advisors who charge for helping the farmer get ahead.

[farmaholic]

This map probably says it all. Remember lines have to be drawn some place and at those boundry lines are "grey areas of transition". Area moisture has a huge impact on soil development over time.

[grassfarmer]

N is dismal in my fields. How much mineralization(?) can I count on? There is enough residue on some fields and has been for a while, I would think it has to be cycling for years already.

That's where your soil micro-biology is important. The living things under the soil are what convert the residue for you. My cows convert a crop into residue these critters feed on and they in turn feed the soil. So many people view the soil as a dead medium to put the seeds and inputs into every year to grow a crop which they then remove. It's why we try to keep something growing in the soil every day we can and why we avoid chemicals wherever possible as they kill the underground workers.