Soil Testing and Plant Diagnostic Services

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Garden, landscape and lawn soil

Jim Curley photoPlants for which recommendations are given

Fertilizer and lime recommendations are provided according to the following groups:

  • Annual flowers and vegetables
  • Cool season turf grasses (bluegrass, fescue, or rye)
  • Warm season grasses (zoysiagrass, bermudagrass, or buffalo grass)

For both groups of turf grasses, either a moderate or high maintenance fertilizer program may be chosen.

If you want recommendations for an individual plant (perennials, vegetables, flowers, fruits, or landscape plants) on the horticulture form check other and write the name of the plant in the blank provided.

Garden, landscape and lawn soil sample information form (PDF)

When to sample

From the perspective of nutrient availability soil can be sampled any time of the year, as nutrient levels vary only slightly from season to season. A small decrease in exchangeable potassium may occur following a productive harvest, yet difference is unlikely to affect fertilizer recommendations.

Ideally, garden soil is sampled between crops such that corrective fertilizer and lime applications an be made before the next season. Although most people take samples in spring, this is the time when our laboratories and county offices are overloaded with samples. A delay in the return of results may occur. Fall or winter sampling leaves more time for planning and corrective fertilizer management.

Obtaining a 6- to 7-inch core for soil samplingcHow to take a soil sample

Obtaining a 6- to 7-inch core for soil sampling.

  1. Discard organic duff on top of soil.
  2. Put 6- to 7-inch soil core in sampling bucket.
  3. Discard soil below 6 to 7 inches.


Coring tools

Coring devices are best for soil sampling. Augers are recommended on rocky soils. Hand samplers at least 3 feet long are desirable because they reduce back strain.


A power drill facilitates sampling in rocky or dry soils. Use a plastic container with a hole in the middle to collect the soil as the auger pulls it out of the ground. Empty the soil out of the plastic container into the soil sample bucket after each successful attempt to get a 6-inch core.

A well taken soil sample results in appropriate recommended rates of fertilizer and limestone.

A soil coring device such as a probe or auger works best to sample soil, because these tools equally collect soil from surface through the entire sampling depth.

Soil probes and augers are available through agriculture companies or your extension specialist may be able to help you locate a supplier.

You can use a shovel, however it is not as good as a probe or auger. If you use a shovel dig a hole to the proper depth, shave a 1-inch slice from the side of the hole, save the vertical, 1-inch wide center portion of this slice.

Sample from uniform areas. Avoid known soil differences (soil color, texture, slope, limestone, fertilizer, manure) in composite samples -- sample them separately.

  • Garden or landscape soil
    0 to 7 inches
    8 to 10 separate cores samples
  • Lawn soil
    4 to 6 inches
    6 to 10 random subsamples

Mix samples to obtain one composite sample in a clean plastic pail (metal pails contaminate the soil with micronutrients) and retain one pint (MU soil sample box full).

Where to submit soil samples

  • County extension centers
    (preferred method)
  • Soil and Plant Testing Laboratory
    23 Mumford Hall
    Columbia, MO 65211
    Phone: 573-882-0623
    Fax: 573-884-4288
  • Soil Testing Laboratory Delta Research Center
    P.O. Box 160
    Portageville, MO 63873
    Phone: 573-379-5431
    Fax: 573-379-5875

Sample submitted directly to the lab should be accompanied by the sample information form and a check for the amount due payable to MU Soil Testing, unless you have an account with us. If you have an account with us fill in the firm and outlet number and we will bill you at the end of the month.

We encourage you to submit your samples through the county extension offices. Firms or businesses may set up individual accounts with the lab to submit the samples directly.

Each sample submitted to our lab should be accompanied by an information form. These forms should be filled out accurately for proper fertilizer recommendations. Including county names is essential for us to mail the soil test results to the appropriate area agronomist or horticulturalist. This information is important to determine the soil region and to complete the soil test summary report for the state.

Samples from firms should contain the firm and outlet number for proper return of results and billing.

Send the original form with the soil sample(s) and retain a copy for your records.

Send soil samples in proper containers such as the boxes and bags specifically designed for soil samples. (Avoid glass jars, coffee cans, plastic bags, etc.) If samples are very wet, allow them to air dry for a day before mailing. Wet samples should not be sent in sample boxes that are plastic lined as they will not allow soil to dry during transit.

Copy the serial number and field/sample ID from the sample information form to the soil sample container.

Garden, landscape and lawn soil sample information forms and sample boxes can be obtained from the county extension centers or at the soil testing labs free of charge or printed from the Web.
Garden, landscape and lawn soil sample information form (PDF)

Soil tests to request

Regular fertility tests
For a general analysis of a soil's fertility, a regular soil test package includes:

  • pH
  • Neutralizable acidity
  • Phosphorus
  • Potassium
  • Calcium
  • Magnesium
  • Organic matter
  • Cation exchange capacity

In certain cases additional tests may be required.

  • Micronutrients
    Zinc, iron, copper and manganese
    Micronutrients may be desired in high pH soils
  • Sulfur
    Sandy soils low in organic matter may have sulfur deficiency
  • Salt content
    (electrical conductivity)
    Soils with salt problems should be tested for salt content (e.g. salt or fertilizer spills, heavy applications of manure, irrigating with alkaline water, can lead to salt problems.

Soil fertility analysis tests and fees

Analysis Fee

Regular soil fertility test

  • pHs
  • Neutralizable acidity
  • Organic matter
  • Bray-1 phosphorus
  • Potassium
  • Calcium
  • Magnesium
  • Cation exchange capacity
  • Fertilizer recommendations
Secondary and minor nutrients
Zinc ($4 if run with regular or iron, manganese and copper) $5
Sulfur $4
Iron, manganese and copper $4.50
Sodium ($1.50 if run with regular) $4
Boron $5
Other special tests
Nitrate $4
Ammonium $4
Nitrate and ammonium (NO3-N and NH4-N -- Inorganic N) $7
Total exchangeable bases (Ca, Mg, K, Na) $6
Electrical conductivity $6
Chloride $6
Particle size analysis $12
pHw or pHs ($2.50 if run with regular) $4
Lime requirement (pH and N.A.) $5
Total Kjeldhal nitrogen (TKN) $12
TKN and Inorganic N and organic N $20
Total phosphorus (TP) $15
Total potassium (TK) $15
Sodium absorption ratio (SAR) $12
Exchangeable sodium percentage (ESP) $12
Base saturation (percent) $12
Bray-II phosphorus $4
Mechlich III or Olson P $4
Organic matter $5
Cation exchange capacity (addition method) $12
Setup fee, if less than five samples for special tests $20
* Walk-in rate
The fee for regular fertility tests varies in counties depending on their shipping and handling costs. Contact your county extension centetr to get the exact cost when submitting through their office.

In the labTurnaround time

  • Soil sample analysis
    1.5 working days after samples are received in the lab
  • Plant, compost, greenhouse media and water analysis
    4 to 5 working days after samples are received in the lab

If samples are mailed allow time to and from the lab. Results of samples submitted through county extension offices are mailed first to the county agronomist or horticulturalist for comments or individualized recommendations. The county then mails the recommendations to the person submitting the sample.

Soil test reports can be emailed on request at no charge or faxed for a nominal fee.

Interpreting the resulti

Interpreting the results and recommendations of soil tests

Interpretations and recommendations are based on the crops you select on the Soil Information Forms. As recommendations differ for different crops, it is important you select the cropping options you intend to plant.

The soil test results you receive will contain the following information:

  • Field information and sample ID you provided on the sample information form.
  • Soil test results
    • pHs
    • Phosphorus
    • Potassium
    • Calcium
    • Magnesium
    • Organic matter
    • Netralizable acidity
    • Calculated cation exchange capacity
    • Electrical conductivity
  • If you requested zinc, manganese, iron, copper, sodium, nitrate, ammonium, or boron these results are also given.
  • Suggested fertilizer requirements in pounds per acre for nitrogen (N), phosphorus (P2O5), and potassium (K2O), are given (zinc, and sulfur are also given if requested).
  • Lime and magnesium treatments are based on soil test levels and crop options.

Interpretations and recommendations

Updated 9/14/11