Texas Plant and Soil Lab - Frequently Asked Questions

Frequently Asked Questions

What is required for the best results in soil testing?
Why should I use a soil test?
Why do recommendations from labs differ?
What could a laboratory in Texas possibly know about my soil?
Why haven't I heard of the CO2 Extraction Method before?
What is so great about the CO2 Extraction Method?
Did TPSL invent the CO2 Method?
What will this test tell me?
So you tell me what's wrong with my soil, but how am I supposed to know what to do?
Is there anything else TPSL can analyze in my soil?
What if I want additional tests run on my sample later on?
What other testing services does TPSL offer?
How long does it take to get my soil report?
What are the types of recommendations offered?
How are the results sent out?
I have a question about a soil report?
How much sample do I need to send in?
How do I ship a sample?
Who do I ship a sample with?
Where do I send my sample?
How much information do I need to send in?

What is required for the best results in soil testing?

A reliable soil test includes proper field sampling, crop and fertilization history, yield goals, and chemical tests for nutrients available for crop growth.

Why should I use a soil test?

To achieve maximum crop yields while using the minimum of water, fertilizer and other inputs.

Different plants remove different nutrients at different rates throughout the growing season. Worse yet, some soils readily leach out nutrients while other soils rapidly tie up nutrients into compounds that are not readily available to the plant. By the end of the season, there could be little available nutrients left.

Proper soil nutritional balance can reduce water usage by 40 to 60 percent and dramatically reduce fertilizer requirements.

YOU CAN’T GUESS about fertilizer application and expect to attain the best economic yields and plant quality.

Why do test results and recommendations from various labs differ?

Laboratories use different procedures and chemicals, techniques and conditions for extracting plant and soil nutrients. Interpretations of these tests also can differ, even when IDENTICAL samples are compared.

What could a laboratory in Texas possibly know about my soil?

Texas Plant & Soil Lab (TPSL®) uses the CO2 Extraction Method to extract Phosphorus (P), Potassium (K), Sodium (Na), Calcium (Ca) and Magnesium (Mg) from your sample. This method duplicates the way plants naturally extract these nutrients from ANY soil.

TPSL® has been testing soils from around the world and providing solutions for growers for more than 72 years.

Why haven't I heard of the CO2 Extraction Method before?

Even though the CO2 Extraction Method is the most accurate in the industry, it is offered only by a handful of labs around the world - as it is extremely labor-intensive and does not lend itself to an automated processing line as does Mehlich III or other commonly-offered soil nutrition tests.

What is so great about the CO2 Extraction Method?

Other testing methods only tell you the Total Content of K, Na, Ca and Mg present.

The CO2 Method tells you only what is readily available to the plant (water soluble) - and what is "in reserve" (Carbonic Acid soluble - to become available with proper soil treatment). Most other methods extract the total content of the sample which includes insoluble nutrient compounds that are not available to the plant.

This explains why a more standard test may show certain nutrients as adequate or high, yet the plants show deficiencies in those nutrients – and why you may see the same test results, ear after year.

Because this method duplicates the way the plant naturally extracts nutrients, it is the most accurate method of measuring P, K, Na, Ca and Mg. It does not have to be adjusted according to soil type. The proof is always in crop / plant performance!

Did TPSL invent the CO2 Method?

No. This was one of the first soil nutrient extraction methods, developed in England by Charles Daubeny of Oxford in 1845. As analytical technology improved, much work was done on the method by the universities of Arizona and Florida, and others in the 20th Century. Building upon those works, TPSL® has further developed and refined the testing standards.

What will this test tell me?

In our exclusive color-coded format, you will get:

Texture, % Organic Matter, CO3, pH, Electrical Conductivity, and Nitrogen (NO3). P, K, Na, Ca, Mg are presented in both H2O and CO2 extractions. Also are Na/Ca, Na/Mg ratios, Total Nutrient Crop Removal Rates and Fertilizer Guidelines - plus micronutrients: Iron (Fe), Zinc (Zn), Manganese (Mn) and Copper (Cu) – with application guidelines.

See an example report here.

So you tell me what's wrong with my soil, but how am I supposed to know what to do about it?

The real value in a TPSL® test is in the recommendations. You get specific fertilization recommendations for your crop in your soil based upon your cultivation practice, whether Conventional, Sustainable or Organic. We are the only laboratory in Texas that provides Organic recommendations.

Is there anything else TPSL® can analyze in my soil?

Yes. TPSL® offers Cation Exchange Capacity (C.E.C.), Boron (B), Sulfate (SO4). Worried about Lead (Pb), Arsenic (As), or Chromium (Cr)? We run these and other HEAVY METALS on soils.

What if I want additional tests run on my sample later on?

Just call us. We retain your sample for at least 90 days just in case you may want additional testing.

What other testing services does TPSL® offer?

We offer a full spectrum of agricultural analytical and consulting services, including:

Plant - ASK THE PLANT™

Texas Plant and Soil Lab's exclusive crop nutrition montoring program to dynamically inform you of your crop's changing nutritional needs throughout the growing season so that you can achieve best yields based upon inputs.

Water

Texas Plant and Soil Lab offers complete water analytical services for potable, effluent, and irrigation water.

Heavy Metals

TPSL® can run Heavy Metals on plants, soils, and water. Please contact us about which heavy metals you are concerned about.

Mehlich III

We perform this basic test as well as the Mehlich III Full-Screen which includes Water-Soluble components.

Organic Analysis

Compost / Compost Tea Nutrients
Manure
Humic Acid
Fertilizers (both Orgainc and Chemical)

Others

Onion Pungency
Nematodes and Disease Diagnostics
Bouyoucous (Texture)
Sieve
L.O.I. (Loss on Ignition - Total Organic Matter)
% Moisture

...and more! Please contact us today at 956-383-0739 and speak with us about your needs.

How long does it take to get my soil report?

Generally, it takes five (5) to seven (7) working days after we receive your sample, if we can send your report by e-mail. Postal mail takes longer.

Heavy Metals and certain additional Micronutrients require 10 working days after we receive your sample.

What are the types of recommendations offered?

Organic, Conventional, or Sustainable.

How are the results sent out?

Results can be e-mailed out at no charge, a hard copy is also mailed both are color-coded.

A report can be faxed at $1.00 a page (typically 3 to 5 pages) but will not be color coded.

I have a question about a soil report?

If you have any question about your soil report, just contact us today at 956-383-0739.

How much sample do I need to send in?

Typcial, two (2) cups of soil is enough if the Comprehensive with Micronutrients is all you want. If you require more testing, a gallon sized locking plastic storage bag will work.

How do I ship a sample?

The best method is in a quart sized locking storage bag (sandwich size). Please do not use glass jars (unless instructed to do so).

Who do I ship a sample with?

U.P.S, Fed-Ex, the U.S. Post Office (Priority Mail), D.H.L., or any other type of shipping courier.

Where do I send my sample?

Texas Plant and Soil Lab (TPSL®) 5115 West Monte Cristo Road Edinburg, Texas 78541

How much information do I need to send in?

If you know the past history of the soil, let us know. We need to know the depth of you soil sample, any fertilizers you may have applied, what crops you want to grow, what crops were previously grown, and what type of recommendations you would like.