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Little River, TX | Mike, the lab that does my hay samples does only NIR. Possibly not as accurate as wet analysis but faster and reasonably consist ant. This lab does not report sulfur.
For mineral analysis I use numbers pulled from feeds & Feeding texts.
While tissue samples are the top third of the plant pulled at late bud to first bloom, most of my alfalfa is cut at quarter bloom to half bloom.
NIR Hay mineral
P 0.19% - 0.26% my average is 0.23%
K 1.68% - 2.52% my average is 1.83%
Mg 0.24% - 0.32% my average is 0.37%
Ca 1.50% - 1.83% my average is 1.63%
Average 19.5% CP or 3.12% N
Tissue analysis
P 0.33% +/- .08%
K 2.50% +/- .29%
Mg 0.31% +/- .04%
Ca 1.76% +/- .30%
S 0.26% +/- .04%
Mo 1 - 10 ppm <15 ppm
I use the NIR Hay mineral analysis to give me something to worry about or to make me over confident. You will want to use numbers that reflect your higher quality harvesting needs.
I use the tissue analysis to develop a fertilizer program. All the fertilizer for the life of the stand is plowed in before planting. My soil is a clay. There is no gravel bed or drain tiles to give the minerals a place to go.
I am not real fond of soil testing. One fielld received 500 lbs of phosphate, the soil test went down and the tissue analysis went up to 0.42% P.
There is only a slight corrilation between tissue analysis and hay test results. Almost like apples and oranges.
I am a little jumpy about potash, for now anyway, as I allowed the labs to talk me into believing I had high levels. The potash deficiency did not make it's self known until some micronutrient problems were addressed.
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Potash on alfalfa in Nevada...
