# Fertilizer Recommendation Based on Soil Analysis



## anthonybilotta (Aug 11, 2018)

Soil Test:



I am a bit confused by the recommendation. Are they recommending 1.3lbs of K once, and then maintain with nitrogen only fertilizer?

Based on the results and using Ridgerunners thread, it would appear that I would need to apply at least 5 pounds of K throughout this year to reach the critical level of K required.

Depending on the answer, I am thinking I would either put down 1.3 pounds of SOP and then maintain with a 29-0-4, or if I truly need 5 pounds or more of K throughout the year, go with a 14-0-14.


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## Ridgerunner (May 16, 2017)

I too am confused by those recommendations. They do not comport with TAMU guidance:
TAMU recommendations for K applications, based on the ppm soil test results, do not result (if you do the math) in achieving the "critical level" in the following chart. Nor does the chart square with the K recommendation given for your soil. Your current/tested K level is 98 ppm. For results of 100 ppm of K, the chart recommends the application of 1.7 lbs of K2O/M and for 90 ppm, the chart recommends 1.9 lbs of K2O/M. Your test recommendation is 1.3 lbs of K2O/M. 
http://soiltesting.tamu.edu/files/soilrecs/landscapeK.pdf
The same type of discrepancy hold true for for N, although the footnotes on your report make additional N recommendations based on turf type.
http://soiltesting.tamu.edu/files/soilrecs/landscapeN.pdf
I understand your confusion and I cannot explain it.
Using the rough figure of 18 ppm for every one pound of K2O/M applied, to reach the 175 CL target you need 175-98 =77 ppm / 18 ppm = a total 4.27 lbs of K2O/M over the year. HOWEVER, do not forget that a large portion of that K will be removed by the turf somewhere in a range of .75-1 lb of elemental K for every 1 lb of N applied. (that can be as much as 26 ppm of K lost for every 1 lb of N), not to mention any amount lost to erosion or leaching.

Having fun yet?  
The important goal is to keep nutrient levels, as reflected in year to year testing, between the ditches. Remember, it's a pretty wide road.


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## Ridgerunner (May 16, 2017)

Oh and considering all of that, I'd probably go with the 14-0-14 or similar. It's my understanding that 15-0-15 fertilizers using SOP are available in the south.


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## anthonybilotta (Aug 11, 2018)

Thank you ! That's exactly what I was thinking as well. I was going to reach out to them later this week and see if I can find out what the discrepancy is. Luckily I found some 14-0-4 with 2% iron from Lesco so i am going to stick with that this year.


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## Methodical (May 3, 2018)

Just for comparison purposes.

My test results (Waypoint) were pretty similar to yours on potassium (123 ppm)and the recommendation was 2 lbs. of K for the entire season (split application). Waypoint suggested 10-0-20, but Site One was out of this, so I went with the Lesco 0-0-20 that is 100% SOP. I applied 1 lb. of K yesterday and will apply the next 1 lb. in the fall, but after I have the soil tested to see where the results for K at that time.


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