# ¿Plant analysis?



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

With alfalfa is normally sampled at a definite stage of growth. Some samples are of selected portions of the plant while a few others do analysis the whole top. Fairly uniform & predictable results result.

One of the California Extension Ph.D's suggest using hay samples to monitor and plan fertility. A logical suggestion, but there is some difficulties. Alfalfa hay is harvested sometime in the vegetative stage, or in early bloom to late bloom and even later. All depending on the market and the weather. 
Then as you might expect the sampling will be a whole top sample. Probably only 10% of the reported plant analysis data is for whole tops. 
Then we have the some times messy harvesting techniques to add to the soup.

Now to the Question: 
Any ideas about what to use as a guide to compare hay analysis results? The object is to fertilize for the optimum yield.

It is my thought that the ratios of the elements does not change as fast as the level of the elements does. The N/S ratio for a high yielding supreme quality hay probably remains the same. 
Now as the potassium percentage decreases, normally the calcium percentage increases. 
From what I read as the protein percentage (CP) goes down so does the percentage for phosphate, potassium, sulfur, and boron. Just not necessarily proportionally. At the same time the percentages for magnesium and potassium increase, but not necessarily proportionally.

What about the micronutrients? No need to apply tons/A of one of the major nutrients when a few pounds of a micronutrient will do the trick.

Any opinions? Suggestions?


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## BCFENCE (Jul 26, 2008)

Hay wilson would now be too late to take a sample of hay in to get it checked to see if im missing anything, I allways get soil samples but never tissue.
THOMAS


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

*Anytime is a good time to sample hay*.

Some hay is sampled two or three times before it is fed. 
I sample the hay on the way to my storage while it is still on the Balewagon. I do it then because it is easier to know which field the hay came from. 
It is not unusual for the hay to be sampled while still on the farm so the customer has a better idea of what they are buying. 
A dairy probably will sample the hay for all the data needed to incorporate it in their ration.

Presently my sampling is to learn the mineral analysis to monitory fertility, and for Crude Protein which I use to set the price. 
Maybe half of my customers like to know CP. and one or two like to know TDN. A Dairy or feed lot wants to know the amount of energy. 
Each level of information has it's own cost. For about 20 years I used paid for the full ration analysis. For a couple of years I paid for CP & TDN. Now I pay for Minerals and if you know the percent of nitrogen you know the percent of CP. (N % X 6.25 = CP %)


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