# Got my soil test back what what would you do?



## Nate926 (Apr 6, 2014)

Guys I am trying to learn more about soil test. I got my soil test back today from the university of Tennessee on a piece of ground I just started renting this year. I have a minimum of 5 years lease but Probably longer. PH was 6.7, P was 40 which is on the low end of high. K was 238 which it say is on the high end of high, ca was 2038 considered sufficient and mg which is considered sufficient. So all it recommends is 30 lbs per acre of N for the new orchard grass I'm plant this fall which is great news to me!! Now my question is should I follow the soil test or go ahead and add more P and K so I don't start to depleat the ground? Thanks guys in advance!!


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## rjmoses (Apr 4, 2010)

For OG, I try to maintain my P and K at 70 and 300 respectively, then, depending on previous year's yield, I add 50+- lbs/ac DAP and 250+- potash / year as maintenance.

Hope this helps.

Ralph


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## Nate926 (Apr 6, 2014)

Thanks for the advice Rjmoses!! When you say 250lbs of potash do you mean 250lbs acre total 0-0-60 fertilizer or after it has been converted?

Example of what I mean by converted 0-0-60 in 50lbs would have 30lbs of actual potash so you would really need 417lbs a acre of 0-0-60. Sorry just want to make sure I'm understanding you right which one your talking about.


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## Bonfire (Oct 21, 2012)

Think of it as units. He puts on 250 units of K per year. Now do your math using 0-0-60 to get to 250 units per acre. So yes, your 417 of actual end will get you 250 units.

Based on your analysis, I'd say the previous tenant didn't just mine it.


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## hog987 (Apr 5, 2011)

Don't you guys worry about too much chloride going into the ground and killing the soil life at those rate of potash?


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## rjmoses (Apr 4, 2010)

I'm sorry, I should've been clearer -- that's 250 lbs/ac. potash. I adjust up/down based off the tonnage produced. E.g., last year I only got one cutting, so I applied 180 lbs/ac potash. (I also adjust based off of price--lower price, I go a little heavier than my yield chart calls for).

I do a grid sample every 4 years and will adjust appropriately.

This is the chart I go by in the off years:

*Hay Yield In*

*Tons/Acre* *DAP * *Potash*

2 24 100

3 36 150

4 48 200

5 60 250

6 72 300

Ralph


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## Nate926 (Apr 6, 2014)

Guys thank you very much! Like I said I'm still learning lol! This is advice I will Defanietly refer to in the future!


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## somedevildawg (Jun 20, 2011)

That's what I do as well Ralph, adjust my input with regards to cost and yield......usually our recommendations are for 300 units......I rarely get there due to ^^


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## hay wilson in TX (Jan 28, 2009)

The amount of chloride will be too much if you exceed 500 or 600 lbs of Potash fertilizer. Fear not though as the Cl is very soluble and will soon dissipate.

The usual rule of thumb is to not apply more than 500 lbs of 0-0-60 potash fertilizer. You can apply potassium Sulfate to your hearts content.

Our soils are not rich in Magnesium so I can apply 1,500 of K-Mag Which is 22% K, 11% Mg, & 22% S or 330 lbs of K & 330 lbs of Sulfur. With 165 lbs of Magnesium in the mix for good luck.

The soils her never need calcium so they never receive extra Mg.

Our clay traps or encapsulates any potassium so any level of K reported is at best a wild guess.

We have an 8.0 pH and for sure ask for the Olsen test for Phosphate. The other chemistry used by labs wildly miss calculates the amount of available P in the soil.
We need to know the percentage of "Free Lime" to make an educated guess for the amount of phosphate fertilizer needed. Our free lime will react with phosphate fertilizer. And quickly I might add. Calcium Phosphate is not soluble in a soil that is not acid in reaction.

All this may give you a hint why I depend on tissue analysis to estimate the amount of fertilizer to apply.

Farming with a calcareous, high CEC clay soil can be an adventure, if your Lab and you are not on the same page.


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## vhaby (Dec 30, 2009)

I think rjmoses was referring to pounds of phosphorus and potassium in the soil by soil test. Please correct me if I'm wrong. With that said, soil test results can differ by states and by labs within states. It depends a lot on the extraction method used by the lab. If the lab in TN and the one used by rjmoses use the same chemicals to extract P and K from the soil then, if you want to do so, you might follow his suggestions. If your lab and his use different extraction methods, then you have a problem attempting to follow his suggestions because the test results will be different.

Also, soils make quite a difference in what the levels of plant nutrients can be elevated to/maintained at. Read HayWilson's comments. On the sandy loam soils on our ranch, I could attain P levels of 70 pounds/acre but I could never afford to apply sufficient potash to get soil test K levels up to 300 pounds/acre.

Speaking of pounds/acre, that is the proper terminology to use when referring to fertilizer application, not units.

Relative to concerns about applying excess chloride when applying potash (potassium chloride), chloride is a plant nutrient and several states have reported crop responses to application of chloride. Chloride has been found to reduce the incidence of some plant diseases. Like Hay Wilson stated, chloride dissipates rather fast. It is quite soluble in water and will leach probably as fast as nitrate as water moves down through the soil.


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## mlappin (Jun 25, 2009)

rjmoses said:


> I'm sorry, I should've been clearer -- that's 250 lbs/ac. potash. I adjust up/down based off the tonnage produced. E.g., last year I only got one cutting, so I applied 180 lbs/ac potash. (I also adjust based off of price--lower price, I go a little heavier than my yield chart calls for).
> 
> I do a grid sample every 4 years and will adjust appropriately.
> 
> ...


One of the reasons I added a scale kit to my baler. Gives the average weight of the bale when finished, then figure average weight x number of bales and divide by acreage to get how much you've removed with each cutting.


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