Monday, March 1, 2010

Tissue Sampling

Today's blog is dedicated to my new corn growing friends from New Zealand and all farmers and gardners.

One tool I have been using for 30 years now is tissue sampling of the growing crop to see what nutrients are in the plant. There are 17 nutrients and most labs test for the 12 most important ones.

I have a personal interest too as it almost time to pull cereal grain samples. Basically you pull or cut the leaf tissue trying to keep soil out of the sample though you always gets some so Iron often comes back High on the tissue test. I never worry too much about Iron, soils are loaded with it.

For my corn growing friends in New Zealand and my North Hemisphere friends this July, I would like you to pull the ear leaf off a corn plant randomly over the field or paddock. Pull one sample per acre to hectare for a total of 10-15 leaves per sample. You can cut the bottom and top off the big leaf to end up with a central piece of plant tissue that can be easily shipped to the laboratory. The drier the better but don't put it in a microwave for quick drying, use natural air drying. I put them on my dashboard under my windshield in the summer and they are often dry by the time I get home.

No sense in shipping water, the lab is going to turn that leaf into ash and measure the nutrients in the ash. Each lab has a long term database of healthy crop tissue to compare to your result so they can tell you how your crop is doing compared to what it could be. Any nutrient deficiency will show up before you see visible signs on the plant. That is important for maximum growth, yield and net profit.

It's a tedious task pulling corn leaves in July in Ohio but February in New Zealand was a joy. My arms didn't break out like they do here. Cereal and oilseed crops are easy to pull compared to corn or maize.

If you want to improve your garden or crop, a tissue analysis will give you that next bit of information you need to decide what to put on your soil.

Here is a typical lab recommendation on how to handle samples from A&L Laboratories, one of the largest labs in the world:

When taking a sample of any kind, there are methods and procedures that will lessen the chance of accidental contamination or that the sample is compromised in some way. We can only report on the information derived from what we recieve. Listed below are instructions on steps you can take to ensure that your sample is both representative of the whole, and that it does not contain unwanted materials that will result in a distorted reporting of actual variables. (Quick links are provided below)
If you have further questions or would like additional clarification, please contact either our local associate in your area or our lab. Thank you.
Soil Plant Tissue Livestock Feed Irrigation Water Plant Disease

SOIL - Procedures for taking good soil samples
Accuracy of the soil test depends on the sample submitted.
Divide your field into areas which have the same soil type, color, slope, fertilizer and crop history.
Take approximately 15 cores from each uniform soil area. Mix them thoroughly in a clean plastic or paper container. Fill the soil sample bag one-third to one-half full from this representative sample.
Scrape away surface litter, and sample to plow depth for all row crops. On permanent pastures, sods, lawns, and turf areas, sample four inches deep.
Several different tools such as a soil sampling tube, soil auger, or spade may be used in taking soil samples. See illustration.Label each sample bag with your name and sample identification. The label information should correspond to the sample I.D. listed on the information sheet. A map is printed on the information sheet for your convenience.
Avoid taking samples from areas such as lime piles, fertilizer spills, gate areas, livestock congregation areas, poorly drained areas, dead furrows, fertilizer bands, old fence rows, or any other unusual area.
Do not use galvanized, soft steel, or brass equipment if trace metal analyses are desired.
How to fill out the information sheet
Fill in grower's name, sample submitted by, and if charged to a third party list their name.
List sample identification and check analyses desired.
If fertility recommendations are requested, list only five samples per page using shaded areas only.
The accuracy of the fertility recommendations given will depend upon the detail of information supplied.
Packaging and shipping instructions
If samples are excessively wet, we suggest they be air dried to a workable condition before packaging.
Place sample bags in a sturdy, spillproof container and pack tightly to prevent opening and spillage in shipment.
Place completed information sheet in an envelope and attach to outside of the package.
Samples should be shipped by United Parcel Service, bus, or air freight.


PLANT TISSUE - Procedures for taking good tissue samples
Collection and preparation of the sample
Be sure to use a clean container. Never use a metal container as the metal may contaminate the sample.
Generally, two cups of lightly packed material provides a sufficient amount to conduct an analysis; one cup may be sufficient if gathering petioles.
If plant samples have soil, dust, fertilizer, or spray residues on them, they will need a light washing, as follows: With the aid of a plastic colander, immerse the sample in cool water containing a couple of drops of PHOSPHATE-FREE detergent, and gently agitate for no longer than about 10 seconds. Extended washing may damage the plant tissue and remove some of the soluble nutrients.
Remove the colander and quickly rinse the sample under flowing pure water. Blot-dry with a clean towel.
Either air-dry samples for one day (below 176 degrees F) or ship as soon as possible in perforated bags to allow air movement and a degree of drying in transit.
Never send fresh samples in sealed plastic bags unless kept cool.
Never freeze samples.
Do not include roots with samples for nutrient analysis unless required.
Specific sampling procedures are required for disease diagnosis. Therefore, please contact us for instructions before sampling.
Sampling Locations: When and where to sample
Before taking tissue samples ensure that timing and location of samples correlates with interpretive data. Instructions for petiole and leaf sampling may differ. Also, comparing samples from both a "good" and a "bad" area often helps in determining corrective action. If specific sampling guidelines are not given, collect recently mature leaves just below the growing point from at least 10 plants. A partial sampling guide follows, although many variations exist. Refer to the A&L Agronomy Handbook or contact us for further information.

Free tissue sample mailing supplies

A&L Laboratories will provide suitable plant tissue sample bags, as well as plant tissue submittal forms at no charge on request. (You may also download submittal forms from this website.)
The information you receive on our reports is as accurate as the information submitted with your sample. Please fill out all submittal forms as accurately, completely and legibly as possible.

If you have never pulled a sample, give it a try. If you have done it before, keep pulling!

My cost of $20 per sample at has been repayed many times over in better crops and better yields.


Ed Winkle

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