# Forage testing and tissue testing



## greenacres (Jun 5, 2008)

When you guys test hay or any forage do you use RFV, RFQ,IVDMD, or tissue testing? I have been using RFV but am switching to IVDMD on the higher quality hays and RFV on the lower quality. I also am looking at tissue testing as a way of fertility ckecking instead of soil testing. Any info on tissue testing will help.


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## greenacres (Jun 5, 2008)

sorry about the wrong title its hard to teach an old dog a new trick (computers)


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## downtownjr (Apr 8, 2008)

Check with your lab or the extension office (if they have a good forage guy)and find what stage or stages they recommend for sampling. I talked to a good forage guy from U of I.
I am going to start this on the second year crop...an extension agent, from University of Illinois told me that plant analysis is the only accurate method to find the current level of the micro nutrients the plants are getting. 
He stated it is better for mineral testing like P and K. Also Boron, Sulfur, magnesium can be checked. It will tell you if the plant is using the chemicals you are putting on the field. He also stated it is better than soil test for nitrogen as most test only look at nitrate. 
A soil test can show P or K is at acceptable levels and his studies show may not be true. I have some literature he gave me...I'll have to find it. But I bet their website or the University of Wisconsin website will be a good source.

That said...I will be doing this for the first time as well because Bob has convinced me to do so if I truely want better yields and healthier plants this is the test that willn tell the tale...letme know what you find...I will post as well.
He also gave me a book from University of Wisconsin...Alfalfa Management Guide...that gives great info on chemicals to test.


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## greenacres (Jun 5, 2008)

got one of the test back from ROCK RIVER LABS in watertown WI, pro 19.9 
mois 17 RFV 153 adf 30 ndf 39.8, haven't priced it yet waiting for the other test to come back from agri king with the IVDMD number


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## Lazy J (Jul 18, 2008)

We used Dairyland Laboratories in St. Clud, Minnesota for all of our forage testing needs. We used NIR to determine Proximate Analysis which was then used to calculate RFV and RFQ. We attempted to use those values to price our hay.

Now that we are in the Eastern Cornbelt we are looking for a new lab for our testing needs.

Jim


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

In most cases a hay analysis will have a reported of lower quality than a tissue analysis. Usually a tissue sample is pulled a few days to a week before the hay is harvested. The hay sample will have shed some leaves in the harvesting process. The tissue sample is usually the top 6 inches of the growth, it is taken to a secure place and cured or packaged with out loosing any leaves.

A tissue analysis is used to determine the availability of the essential elements present in the soil. A hay analysis is mostly to determine feed quality. You can look at the minerals reported as a poor mans plant analysis, but it will be subject to a good bit of error. That said the mineral report is a handy tool for fertility.

As for hay analysis some people are satisfied with a Crude Protein and maybe Total Digestible Nutrients. Others want a RFV or a RFQ which is a computed estimate of feed quality based on fiber and some times CP.

For fertility I use tissue analysis on an average of every 3 years. For Hay I sample every field and every cutting for feed value.


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## jliltd (May 12, 2010)

We have started testing for determining price of our alfalfa crop and have sent same samples to three different labs with a 40 point difference in RFV. On 330 acres a 40 point spread is $10K difference in price with the dairies. The low RFV came from what locals call a "dairy lab" while the high RFV came from a university-endorsed renowned lab. Wha't s the point in testing with this much variation? What was supposed to create a level playing field has caused more trouble then our old subjective valuation method.


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

First off, for determining price you want to use the same lab your buyers like. 
Now the Dairy Lab knows their primary customer wants a low reported test for a lower price. 
The certified lab has a different motive. 
The California Hay market for the California Dairy Industry understands this very well. 
You can attempt to caalibrate the Dairy Lab's results and put a value on your hay accordingly. That might work. 
What are we paying for an analysis? $20 to $50? What does a Gold Ore analysis cost? $1,000?
We simply are not paying for that kind of accuracy!
Try this Double or triple sample a stack. You can do that your self all at one time or you can have three people sample a stack, or a truck load, at different times, & unobserved. The reported values will be different!

Consider California again. Much of their hay is sold by Grade. Supreme, Premium, &c. All Supreme hay for one price, and all Premium considerably discounted. 
The "natural variability" in sampling can be significant. There really is no significant difference between 181 RFV & 179 RFV while a ten or twenty point spread is easy just with "natural variaability". Throw in weighted testing and the report can be 149 RFV.

You realize that even Certified Testing Facilities have different grades, based on blind testing by the National Forage Testing People.

It all boils down to what the buyer is willing to pay and what the seller is willing to accept. If you will accept a price based on 145 RFV when you know that skilled sampling, and quality analysis will repoprt 185 RFV then that is the value of your hay.

NOW, I use hay teating as my promary fertility monitoring tool. I only use CP as the pricing devise. Realizing that ssupply and demand has the final say.


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## UpNorth (Jun 15, 2009)

Tissue testing is a valuable tool, but should not be the only analysis for determining what you need to fertilize. Pairing tissue tests with soil tests with give a more complete picture of what is going on in your fields. Each type of test has it's strengths and weaknesses and it's important to understand them.

The RFV, RFQ, IVDMD choice is similar (all tell something-none tell everything), but the big thing is to have the tests that your market demands.


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

Tissue testing is a valuable tool, but should not be the only analysis for determining what you need to fertilize. Pairing tissue tests with soil tests with give a more complete picture of what is going on in your fields. Each type of test has it's strengths and weaknesses and it's important to understand them.
I agree up to a point. For 20 or so years what you state is my management system. Early on I found out that with my soil there was a correction factor for K, Mg, & Ca reported values, based on soil CEC. Then I found out that the Estimate CEC value is really not all that wonderful. I needed to use a Measured CEC value. Kind of costly but CEC does not change with cropping. The trick is to CEC times a magic factor = desired soil test value. In my case in the range of from 450 ppm K to 600 ppm K is required to insure a sufficient plant analysis for potassium. 
This is due to trapped in the clay structure potassium is found and reported when the samples are dried and crushed. Potassium that is not truly available to the growing crop at that time. 
Different labs reported wide ranges of calcium in my soil. Anywhere from 42,000 ppm Ca to 3200 ppm Ca. 
Actual calcium levels are in the 8,000 ppm Ca range plus 6% to 10% free Calcium Carbonate.

Many tests will tell us that most of the minor elements and all the micro elements test results are not credible. That left mostly pH & organic matter for soil testing to report. Here with that much calcium pH just does not change from 8.0. 
That left plant analysis as the primary tool fertility monitoring tool. 
Then Steve Orloff in California came up with the idea of using hay sampling to monitor fertility. His reasoning was for Dairy Hay alfalfa is cut in bud stage and plant analysis is sampled at first bloom. Why not sample the bales and call it whole tops sampling. 
I had been looking at Hay Test mineral analysis but not real close. Besides mine did not report sulfur or boron. 
My customers seldom ever looked beyond CP & amount of leaves so I changed to using a Tissue analysis for my hay testing. It is simple to determine CP. ( N% X 6.25 = CP )

The RFV, RFQ, IVDMD choice is similar (all tell something-none tell everything), *but the big thing is to have the tests that your market demands*. These values are really more value as pricing aids or tools than feed value. California and some other Western states using their version of TDN also fits that category. The ultimate judge of feed value is the milk in the tank, the meat on the bones, or the ability to run or pull. The daily level of milk in the tank is also a good soil fertility judge for the grazing dairy. Fecal samples is another good way to judge feed quality.

As a provider of hay, I will do what ever testing the customer is willing to pay for. If the customer does not care about RFV, RFQ, ether NDF, net energy, then I will test for what interest me. HERE my customers will not pay for alfalfa that is over 20% maybe 22% CP, or bermudagrass hay that is over 12% CP. Above these values there is a Yield Drag, and when selling by the ton or by the bale, then quantity is King.

Again, Thank you for your input.


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