Guidelines for Collecting Samples

1. Areas cropped or fertilized differently or those with different soil types or textures should be sampled separately.  For large areas, one soil sample should represent 10 acres or less.  For home gardens, lawns, or ornamental beds, only one sample is required per uniform area.
2. Use a soil auger, spade, or shovel.  Samples from cultivated areas should be taken from the surface to a depth of 6 to 8 inches.  Samples from pasture or turf should be taken only 2 to 4 inches deep.
3. Soil cores should be approximately the same size throughout their depth.  No adjustments are needed if using a soil probe.  To do this when using a spade or shovel, take a thin slice from the side of a V-shaped hole.  Take sub-samples from at least 12 locations within the sample area.
4. Place the sub-samples in a clean plastic bucket and mix thoroughly.
5. Do not heat a moist soil sample to dry.  Spread it out on newspaper and let air dry overnight.  Crumble and mix before it hardens.
6. Label or number the soil bag.  Fill bag to fill line (the equivalent of 2 cups).  Do not use the same number for more than one sample.
7. For soilless media/mixes, 1 quart of material should be submitted.

The sample submitted must be representative of the feed or forage to be fed if the analysis is to be of value. About a quart of sample is needed.

1. Hay Samples. Sample each cutting or batch of hay separately. Take samples from the inside of 10 to 20 small bales or 3 to 4 large bales and combine these for the final sample. Place final sample in plastic bag and seal with a twist tie.
2. Silage Samples. Take a handful of silage from 10 to 20 random locations over the vertical exposed surface in trench or bunker silos. Mix samples thoroughly in a bucket and fill plastic bag. For upright silos with mechanical unloader, take samples as the silage is being fed.
3. Mixed feed and grain. If feeds are uniformly mixed, the sample may be taken from any area in the lot. Grain and bulk feeds are easier to sample with a grain sampling probe. Place about 3 cups in a plastic bag and seal with a twist tie.

Supplies for samples are located at your local extension office. Samples may also be submitted in a brown paper bag. The outside of the bag must include your name and Sample ID, matching the Plant Analysis form.

1. Do not sample pesticide, dust or soil contaminated tissue.  If all the tissue available is dusty, wash gently in flowing, clean water.
2. Do not sample tissue that is diseased or damaged by insects or machinery.
3. Place the plant tissue sample directly into clean paper bags or envelopes.  If the plant tissue is wet or succulent, leave out in the air one day until wilted and partially dry.  Do not put samples in plastic bags.
4. When sampling suspected nutrient-deficient plants or if specific sufficiency ranges are unavailable for your plant, take two samples if possible; one from the normal tissue and the other from abnormal tissue so a comparison of the results can be made.
5. When sampling, both the stage of growth and plant part collected are important.  Be sure to collect the proper plant part at the recommended stage of growth.  A sampling diagram is shown below.  If an analysis is desired on the leaf portion of the plant, only the leaves should be submitted with the stems and roots removed.
6. Specific sampling instructions for various crops are given here. If specific sampling instructions are not given for the crop you wish analyzed, sample leaves which are representative of the current season’s growth during the mid-period of the growth cycle or just before seed set.
7. Submitting the equivalent volume of a half lunch bag of fresh tissue will insure that there will be enough sample for the desired analyses.
8. If an analysis is desired on the petioles of a plant, 20-25 large petioles or 35-40 small petioles should be submitted.
9. Label bag and make sure form sample number matches with sample.

A laboratory analysis is no better than the sample submitted for analysis.  The sample should represent the conditions of use as much as possible.

Sample Bottles:  Bottles should be clean.  Plastic bottles should be used.  At least 1 pint of sample is required.

Sampling Technique:  Before filling, rinse the sample bottle out two or three times with the water being collected.  Fill the bottles completely and cap tightly.

Lakes and Reservoirs:  Choose location, depth, and frequency of sampling depending on local conditions and the purpose of the investigation.  Avoid surface scum.

River or Stream:  Sample from the middle at mid-depth.

Wells:  Be sure the pump has been delivering water for at least 30 minutes.  If the well is new, a sample taken after several hours’ delivery should be more representative than the samples taken earlier. Our lab tests well water for agricultural purposes only. For drinking water or environmental testing contact SC Department of Environmental Sciences, ECO Water Systems, or a private environmental lab.

Distribution Systems:  Flush lines sufficiently to ensure that the sample is representative of the supply.

Handling and Storage:  Avoid sample agitation and prolonged exposure to air.  Identify each bottle by attaching an appropriate label.  Submit the samples for analysis as soon as possible.  (Ideally the samples should be analyzed within 24 hours after sampling.)  Keeping the samples cool (preferably refrigerated) and covered from light will reduce changes in sample composition between sampling time and analysis by the lab.

For a more in depth guide to collecting water samples, please visit this article.

Obtaining a representative sample is critical for getting a good estimate of nutrient value. General sampling procedures for solid and liquid waste can be found in the publication "Recommended Methods of Manure Analysis A3769".

The sample submitted must be representative of the waste to be land applied if the analysis is to be of value.  The nutrient content of animal waste is affected by several factors:  The type and size of animal, the feed source, the animal housing unit, the storage and handling of the waste, and the time of the year.  If any of these factors differ among wastes, separate samples should be obtained.

For submitting samples to our lab, use of our lab supplies is preferrable and can be obtained at your local county extension office. Both solid and liquid containers are available. If you're unable to obtain our supplies, solid waste samples may be submitted in a gallon-sized zip container and must be double-bagged to ensure no leakage during shipment. For liquid samples, use a plastic container with a screw top lid. Do not use water bottles. About a cup of liquid is required for liquid samples. Do not submit more than a cup of liquid.

If several weeks expire between sampling and application or if rainfall or waste additions alter the waste, another sample should be obtained. 

Solid Wastes

For submitting samples to our lab, mix the composite sample thoroughly, then using the laboratory bags place about a pint of solid waste in the small inner bag.  Label the inner bag with the sample ID used to identify the sample on the sample submission form.  Twist-tie inner bag then zip-lock in large outer bag.  Keep the sample cool.  If the waste sample is not mailed to the Lab on the same day it is sampled, it should be kept refrigerated.

Sample forms SHOULD NOT be sealed inside the sample bags.

Liquid Wastes

For submitting samples to our lab, mix the composite liquid thoroughly, and then obtain about a cup of the liquid for the sample.  Fill the laboratory sampling bottle leaving 1 inch of air space for the sample to expand.  Keep the sample cool.  If the waste sample is not mailed to the Lab on the same day it is sampled, it should be kept refrigerated.

Sample forms SHOULD NOT be sealed inside the sample bags.

Soil Sample

Soil samples should be obtained from the fields on which the animal waste will be applied and their nutrient status determined.

Obtaining a representative sample is critical for getting a good estimate of nutrient value.

The sample submitted must be representative of the compost to be used if the analysis is to be of value.  The number of sub-samples will depend on the size of the pile, but in general, take 1-pint sub-sample sizes from at least 5 places around the pile.  At each place, sample 3 different depths.  Take one at the surface, take the second midway between the surface and the core, and take the third at the core.  Mix all of these sub-samples thoroughly in a clean 5 gallon plastic bucket.  For your sample, fill the sample bag with 1 pint of this mixture.  If bulk density is required, 2 quarts of this mixture must be submitted. 

Fill out one form per sample.
(Go to the 'how to complete forms' for more information.)

For submitting samples to our lab, bags are available at your local Extension office or use a quart sized plastic bag.