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Category: Blog, texas plant and soil lab
The final product that Texas Plant and Soil Lab delivers is not simply test results – it is the remarkable yields and quality of crops. To achieve this, Texas Plant and Soil Lab has to deliver solutions to the (often profound) problems that have been crippling the grower. To that end, the lab takes the […]
Wed, 25 Nov 2015 06:07:59 +0000

Category: Videos, Idaho, Stu Ellis, Sugar Beets, The 2015 Pacific Northwest Field Interviews
Texas Plant and Soil Lab presents The 2015 Pacific Northwest Field Interviews hosted by Stu Ellis. Today’s feature video is number eight in the series, featuring Sugar Beets in Idaho, where after years of decline and disease this farm was able to generate a fifty-percent increase in harvest yields with a significant increase in sugar […]
Fri, 20 Nov 2015 05:40:44 +0000

Category: Videos, Idaho, Stu Ellis, The 2015 Pacific Northwest Field Interviews, Wheat
Texas Plant and Soil Lab presents The 2015 Pacific Northwest Field Interviews hosted by Stu Ellis. Today’s feature video is number seven in the series, featuring Woodland Wheat in Idaho, where they went from 70 bushels to 130 bushels with 15.5% protein all the while using much less water. Join us as we feature a […]
Wed, 18 Nov 2015 05:37:27 +0000

Category: Videos, Idaho, Stu Ellis, Sugar Beets, The 2015 Pacific Northwest Field Interviews
Texas Plant and Soil Lab presents The 2015 Pacific Northwest Field Interviews hosted by Stu Ellis. Today’s feature video is number six in the series, featuring Sugar Beets in Idaho, with considerably higher yields and sugar but no insects or disease. These sugar beets have enormous, beautiful roots – have you ever seen anything like […]
Mon, 16 Nov 2015 16:49:48 +0000

Leaf / Petiole (Stem) Sampling

To ensure accurate results, maximum yield and adequate fertilization, plant samples must be very specific. Nutrient content of leaves will vary by location of the leaf on the stalk. The age of the leaf is also makes a big difference.

Included in your sample, inform the lab of the exact age of the leaf and location of the leaf in regards to the plant.

Size of Plant Test Sample

The number of leaves or stems to take per plant depends upon the number and size of plants. In instances of several plants, such as crops or orchards, one leaf or stem per plant can be taken until you have an overall sample of twenty to fifty. The objective is to achieve four to five grams (the equivelant weight of two American Dimes) of dried plant material. In the instance of one or just a few plants, multiple samples will have to be taken.

Which to Take, Leaf or Petiole (Stem)

Take leaf for long growing plants: citrus, pecan, shrubs, onions, etc.
Take the most recent fully developed leaf.

Take petiole (stem) for short-term plants: cotton, melons, peppers, soybeans, cabbage, etc.


When taking a leaf sample, pinch the leaf off at the stem.


When taking a sample of grass, you may take the whole plant or clippings.


Download PDF instructions for Pecan Sampling and Testing information.

Petiole (Stem)

For petiole (stem) samples remove the leaf at the stems. Save a few leaves to include for observation, but you may discard the rest.

Preserving Samples

Select test station areas. Mark and map with Management Area ID.

Test areas should be confined to similar soil types and conditions and should not exceed five to ten acres. It is better to be very selective in taking samples than to try to use volume to be representative. Results of specific samples from a similar area can be averaged with results from other samples for treatment as a whole. However, averaging samples from all over the field does not tell you the variations, which could show major differences that need separate treatment. For best results, map areas (stations) that were sampled. Sample same area each time to compare with previous tests, as reports will have previous dates for reference. Avoid variations due to sampling of different areas.

Sample the same specific areas or plants each time as representing larger areas to be treated. As management is intensified, the entire farm can be placed under testing for each ten to forty acres. For the best soil fertility and plant nutrition management program, a history of specific site sampling information is better than an average sampling.

Plant Sample Handling

Wash samples gently before they wilt to remove any contaminates such as dust and sweat. For petioles (stems) rinse in water without crushing. For leaf samples, wash with a non-phosphate liquid detergent such as Ivory or Joy, and lightly rub the surface of each leaf. Rinse at least once in clean water. The last rinse for leaves or petioles (stems) should be distilled water if possible. Handle with clean hands and place only on clean surfaces or in paper bags. A simple rinse is better than nothing!

Place in paper bag so leaves / petioles (stems) can dry. Do not enclose in airtight plastic; If you must ship them in plastic bags punch many holes in the plastic used so they do not mold in transit to the lab. The first thing the lab must do is dry the leaves. The process of drying can be started as soon as leaves are washed.

Dry plant samples can be stored for quite some time without deterioration. If you choose to dry your samples, dry them slowly, exposing them to no higher than 100 degrees Farenheight for 8 hours or longer. Use only low heat if any. Suitble low heat examples are air conditioning exhaust or hair dryer on lowest heat setting.

Identification of Sample

You should be sure to record date taken, the size and age of the plant, the growth condition of the plant, the moisture level, any insect or disease damage, production and fertilizer history, a copy of any previous soil tests, and any other observations that could influence growth. Include all information with the samples in the shipment to the lab. Make sure to fill out the entire Plant Analysis Information Sheet each time samples are submitted to lab.

Interpretations of Lab Results and Recommendations

Lab results and recommendations are much better when all information about the soil and crop is furnished.

Crop Logging

Utilizing multiple sampling dates is a proven method for best nutrient management. Take samples several times at critical plant periods during the growing season to adjust the treatment for better results.

Please contact us at 956-383-0739 if you have any trouble or questions regarding your soil sample.

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