# Nutrient stratification



## stack em up (Mar 7, 2013)

So you fellas with long term hay fields (longer than like 3 years) what are you doing to combat nutrient stratification? I’ve always felt like with my alfalfa fields topdressing the P, K, Boron and some micros is good and all but I worry about it all being stuck in the top 2”. Phosphorus moves thru soil at a rate of about 1/2” per year so the deep tap roots will never see it. In our corn, we deep band the fertilizer at 8” or even just dig it in, but that’s maybe a 4” depth average.


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## hog987 (Apr 5, 2011)

Run an aerator over the field than try to broadcast fertilizer before a rain. The aerator is set to go about 6 inches deep. A rain will wash some of the prills into the aerator holes.


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## r82230 (Mar 1, 2016)

stack em up said:


> So you fellas with long term hay fields (longer than like 3 years) what are you doing to combat nutrient stratification?


Absolutely nothing.

Presently my oldest seeding is a 2010 model (it's also the last of the Vernal). My newest is 2016 model (hy-bred). None if my fields have seen any iron (chisel or moldboard, field cultivator/disk), since the late 80s or early 90s.

My system, the year before re-seeding, take extensive soil samples, apply lime and potash/phos./etc. as test results call for (PH is what I really want dialed in for alfalfa), that fall. Next year take off 1st cutting early June, let re-growth happen, spray with RU, apply fert called for by soil test if needed (in early August). Yes I'm soil testing again (I do soil test in early July after 1st cutting as a rule of thumb). Spray RU again, a day or two before no-tilling 20# of coated seed Aug 10th - 15th. Planting at half rate (10# a pass), in two different directions.

FYI, I pull soil tests from top 4 inches only. I have more than tripled my hay production since 2008 when I started soil testing more (and following the results). Now I am more on a maintenance program, lime every couple of years, fertilize every year and only spot soil test (to help ensure I'm doing a good job at maintaining fertility).

This year my fert cost is about $105 an acre. I put down 350# pot, 50# Phos, 50# of AMS (for the sulfur) and 2# Boron.

HTH

Larry

PS Full disclosure, most of what I do, I have gleaned from the great folks here on HT. Hats off to HayWilson and Vhaby in particular.


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## r82230 (Mar 1, 2016)

Forgot to attach an article I recently read about phosphorus & K.

https://www.progressiveforage.com/news/industry-news/alfalfa-checkoff-developing-practical-phosphorus-and-potassium-tissue-test-recommendations-and-utilizing-struvite-in-modern-alfalfa-systems

Larry


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## slowzuki (Mar 8, 2011)

Continuous grass is well adapted to being eaten and dropped as manure on the surface or maturing and laying on surface and decomposing, both are forms of top dressing.

I would expect as long as you apply your fertilizer and manure annually the return of nutrients to correct depth for the roots will occur at the correct rate.

Off course when fighting to raise something in less preferable soil conditions this may not be ideal.


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## glasswrongsize (Sep 15, 2015)

Just thinking here, but I think it would depend greatly on the health of the soil and its ability to sustain worms, dung beetles, and other creepy crawlies that make holes in the soil that allow stuff to run-off into the depths of the soil.

Here, the ground dries and cracks multiple inches deep regularly. These cracks should allow for rain to carry recently top-dressed goodies deeper at a rate substantially more than the 1/4 inch per year of going THRU the soil.

I think cracks n bugs n organic matter (to make the soil more "porous") will all increase the rate of movement. Ma Nature has a way.

Mark


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## vhaby (Dec 30, 2009)

glasswrongsize said:


> Just thinking here, but I think it would depend greatly on the health of the soil and its ability to sustain worms, dung beetles, and other creepy crawlies that make holes in the soil that allow stuff to run-off into the depths of the soil.
> 
> Here, the ground dries and cracks multiple inches deep regularly. These cracks should allow for rain to carry recently top-dressed goodies deeper at a rate substantially more than the 1/4 inch per year of going THRU the soil.
> 
> ...


Good points Mark. Dung beetles are amazing creatures. Deep soil sampling in long-term pastures at Texas A&M- Overton, have shown phosphorus movement to about 18-in deep in the more sandy soils, largely due to dung beetle activity.

The Blackland soils of Texas and Alabama are high shrink swell examples of deep cracking soils that behave similarly to what you describe. One of the old time soil scientists once laughingly wrote in a soil classification book that the Texas Blackland soils, when dry, can form cracks so wide that a calf can break a leg when stepping into one of them.

Vincent


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