How to Take a Soil Sample for Laboratory Testing

A laboratory soil test is only as representative as the soil you send. The laboratory may measure pH, nutrients, organic matter, soluble salts, soil-health indicators, texture, or contaminants with excellent analytical precision, but it is still testing a small amount of material taken from a much larger root zone. If that small amount came from the wrong depth, a freshly fertilized pocket, one wet corner, or several unlike areas mixed together, the report can be technically accurate and practically misleading.

For cannabis growers, the sampling method should not be invented around cannabis root depth or a preferred nutrient chart. It should follow the laboratory method and the question you are trying to answer. Routine garden fertility tests commonly use composite samples from the cultivated surface layer, often around 6 to 8 inches (15 to 20 cm) deep, but laboratories differ. Soil-health, nitrate, salinity, heavy-metal, bulk-density, and soilless-substrate tests can require different depths, amounts, storage conditions, or preparation.

The repeatable method is simple in principle: define one uniform sampling area, confirm the laboratory protocol, collect equal-depth subsamples across that area, mix them into one representative composite, reduce the composite to the laboratory-required amount, label it precisely, handle it as the test requires, and verify surprising results before making a major correction. This resource shows how to do each step without turning one handful of soil into a false picture of the whole garden.

Start With the Test, Not the Shovel

Before collecting soil, decide what the laboratory result needs to answer. “I want to test my soil” is too broad because different analyses do not always use the same sample preparation. A standard fertility test may be designed around air-dried mineral soil. A soil-health package may need fresh soil kept cool because respiration, aggregate stability, active carbon, or other biological and physical indicators can change after collection. A contamination investigation may require a different spatial design because the goal is to find or characterize hotspots rather than calculate only the average fertility of a bed.

Call or read the laboratory instructions before sampling. Confirm the test package, required soil volume, sampling depth, whether the soil should be air-dried or kept field-moist, packaging requirements, shipping restrictions, and any special rules for the material you plan to submit. This one step prevents a common failure: collecting a “perfect” sample that the chosen method was never designed to analyze.

Important: Laboratory instructions override generic internet sampling rules. Depth, moisture condition, sample quantity, container type, and shipping method can all depend on the analysis requested.

Routine fertility and pH testing

Routine garden soil tests usually focus on chemical properties such as pH, extractable nutrients, organic matter, and sometimes soluble salts or texture. For cultivated garden soil, many university extension protocols use the upper cultivated layer, commonly around 6 to 8 inches (15 to 20 cm). That is a horticultural sampling convention, not a cannabis-specific root-depth target. The laboratory has calibrated its interpretation around a defined sampling depth, so taking a much deeper core simply because a cannabis plant can root deeply may dilute the surface fertility signal and make the recommendation harder to interpret.

If the laboratory offers crop-specific recommendations but does not have a validated cannabis calibration, do not disguise the crop as tomatoes or another plant to force a fertilizer prescription. Ask what the report can validly provide. Raw pH, nutrient, organic-matter, salinity, and texture data can still be useful, but the amendment rate may need interpretation that respects local soil chemistry and the absence of a cannabis-specific calibration.

Soil-health and biological testing

A soil-health test can include measurements that respond to sample storage and moisture. Cornell Soil Health Laboratory, for example, instructs users to keep samples away from heat and direct sun, refrigerate them after returning from the field, and ship promptly. That is the opposite of the common instruction to air-dry a routine fertility sample before mailing.

The practical rule is not “always dry” or “never dry.” The rule is preserve the sample in the condition required by the method. If the laboratory measures biological activity, a warm sealed bag left in a vehicle can change the sample before it reaches the bench.

Heavy metals and suspected contamination

If the question is lead, arsenic, cadmium, petroleum history, industrial fill, roadside deposition, treated lumber, or another contamination concern, treat it as a contamination investigation rather than an ordinary nutrient test. Hotspots matter. A single composite can answer “what is the average concentration in this defined area,” but it can also hide a small high-concentration zone if unlike areas are mixed together.

Contaminant sampling may require dedicated clean tools, more than one composite sample, different depths, or separate sampling of suspected hotspots. Follow the chosen laboratory or local public-health protocol. Do not use a nutrient recommendation to make a safety decision about contaminated soil.

Safety Note: A routine fertility test does not automatically screen for lead, arsenic, cadmium, petroleum products, pesticides, or other contaminants. If site history creates a contamination concern, order the appropriate analysis and follow its sampling protocol.

Problem diagnosis is different from baseline fertility

A baseline test asks what an average managed area looks like. A diagnosis asks why one area or one plant behaves differently. Those questions should not be sampled the same way. If one corner of a bed is chlorotic while the rest grows normally, mixing that corner into a whole-bed composite can dilute the difference you need to see.

For diagnosis, take a separate sample from the problem zone and a comparison sample from a healthy zone managed in the same way. Keep depth, timing, and sampling method matched. The paired result is often more informative than one “average” sample because it lets you ask what actually differs.

Field Advice: Write the question on the sample form before collecting soil: baseline fertility, problem diagnosis, salinity, soil health, texture, or contamination. A clear question makes the sampling design much easier to defend later.

Define One Sampling Unit Before You Collect Soil

The most important spatial decision happens before the first core: decide which ground belongs in one sample. A composite sample is useful only when its subsamples come from an area that you genuinely want represented by one average result. Soil type, slope, drainage, amendment history, crop history, irrigation pattern, and visible plant performance can all justify separating an area into different sampling units.

Imagine a backyard with a raised bed filled with imported soil, a native-ground planting strip, and a low wet corner that receives runoff. Those are not three places to collect soil for one bucket. They are three different soil systems. Mixing them may produce a report that accurately describes none of them.

Separate areas with different management histories

Do not mix soil from a bed that received compost with soil from a bed that did not. Do not combine a heavily limed area with an untreated area, or a frequently fertigated strip with native soil outside the irrigation pattern. The laboratory will blend those histories into one number and you will lose the information needed to manage either zone correctly.

The same applies when a garden has changed over time. A new raised bed built this year and an older bed reused for five seasons may contain the same crop, but their nutrient pools, organic matter, salinity, and physical structure can be very different. Treat them as separate units unless your actual management decision is to average them.

Separate landscape positions when water behavior differs

Topography changes soil even when the surface looks continuous. A low spot may accumulate water, salts, eroded fine particles, or organic matter. A slope may lose topsoil and dry faster. A compacted path may have the same parent soil as the planting bed but a completely different root environment. University sampling guides consistently warn against mixing atypical wet spots, eroded areas, fence lines, burn areas, and other unusual zones into a representative fertility sample unless those areas are the actual target of the test.

Remember: An unusual area is not “bad data.” It is often a separate sampling unit. Excluding a wet corner from the average makes sense only if you sample that wet corner separately when it matters to your decision.

Keep obvious problem plants out of a baseline composite

If one cannabis plant is stunted and every neighboring plant is vigorous, do not automatically add soil from its root zone to a whole-bed baseline sample. That can blur the very contrast you need. Take a problem-zone sample and a healthy comparison sample at the same depth and with the same method. If both results are similar, the cause may lie outside the measured soil chemistry, such as root damage, irrigation distribution, disease, compaction, or genotype.

Master Advice: Draw a simple garden map and assign each planned sample an ID before collecting anything. Spatial organization is easier to fix on paper than after several unlabeled buckets are sitting beside you.

Choose the Right Depth, Tools, and Timing

Sampling depth is not a cosmetic detail. Nutrients, salts, organic matter, pH, and contaminants can change sharply with depth. If one year you sample the top 4 inches and the next year you sample 10 inches, a change in the report may partly reflect the sampling method rather than a real change in soil.

Use the laboratory depth, then keep it consistent

For routine cultivated garden soil, extension laboratories often specify approximately the upper 6 to 8 inches (15 to 20 cm). Some protocols use 6 inches, some 6 to 8 inches, and others separate surface and subsurface layers for specific management systems. That range should be treated as a common horticultural convention, not a universal cannabis rule.

If a laboratory specifies 0 to 6 inches, sample from the soil surface after removing loose mulch down to 6 inches at every subsample location. Do not take one core to 4 inches, another to 9 inches, and assume mixing will correct the inconsistency. A soil probe helps because it removes a more uniform column. With a spade or trowel, take a vertical slice of even thickness so the top of the profile is not overrepresented.

Pro Tip: Mark the target depth on your probe, trowel, or a clean measuring stick before you begin. Consistent depth matters more than trying to guess the exact depth at every hole by eye.

Do not sample deeper just because cannabis can root deeper

A large outdoor cannabis plant can explore soil well below a routine garden sampling depth, but the laboratory recommendation is often calibrated to a specific sampled layer. A deeper core can dilute nutrients concentrated in the cultivated surface zone and make the interpretation inconsistent with the laboratory method. If you have a specific subsoil question, such as salinity, mobile nitrate, restrictive layers, or a suspected contamination profile, collect a separate depth according to the laboratory protocol rather than silently making the routine sample deeper.

Use clean tools that will not bias the analysis

A stainless steel soil probe or auger is ideal. A clean spade, trowel, bulb planter, or large knife can also work when used carefully. Collect subsamples into a clean plastic bucket unless the laboratory specifies another container. Tools and buckets that previously held fertilizer, lime, salts, pesticides, or amendments can contaminate the sample enough to alter results.

For micronutrient or heavy-metal testing, tool composition matters more. Some extension guidance warns against galvanized, bronze, or brass tools because they can contribute metals to the sample. When trace-element accuracy matters, follow the laboratory’s decontamination and tool-material instructions rather than relying on equipment that is merely “garden clean.”

Sample before major amendments when you want a baseline

If the purpose is to decide whether lime, sulfur, compost, potassium, phosphorus, or another amendment is needed, sample before applying it. A core taken directly through a recent top-dress pocket or fertilizer band measures that concentrated patch, not the established root zone. If amendments have already been applied, tell the laboratory what was used and when, and avoid deliberately targeting visible granules unless the test is investigating that exact treatment.

For year-to-year trend tracking, sample at roughly the same time of year, at the same depth, and preferably through the same laboratory and method. Soil chemistry can shift seasonally with moisture, fertilizer use, plant uptake, and mineralization. Consistent procedure makes trends more interpretable.

Tip: Take photos of the sampling area and note the date, recent irrigation or rain, and recent amendments. These details often explain a result that looks strange months later.

Avoid extremely wet soil unless the laboratory tells you otherwise

Saturated soil is messy to composite and can be difficult to subsample evenly. Many extension programs recommend avoiding extremely wet conditions for routine sampling. If you must sample wet soil because the diagnosis is time-sensitive, follow the laboratory’s storage instructions. Do not automatically dry it with heat.

Remember: Never oven-dry a routine soil sample unless a laboratory explicitly instructs you to do so. Heat can alter the sample, and many labs that want a dried sample mean room-temperature air drying.

Build a Representative Composite Sample Step by Step

Once the sampling unit, depth, and laboratory protocol are fixed, the field procedure should be deliberately repetitive. The goal is not to find the “best-looking” soil. The goal is to give every representative part of the sampling unit a reasonable chance to contribute to the final composite.

Step 1: remove surface material without removing the soil profile

Move aside loose leaves, mulch, stems, surface manure, stones, and undecomposed debris where the laboratory protocol calls for mineral soil. Do not scrape away the actual topsoil. If surface stratification is the question, follow the specific protocol instead of removing the layer you intend to measure.

Step 2: collect a vertical core or slice to the target depth

Push the probe straight down to the marked depth. If using a spade, open a small hole and cut a narrow vertical slice from the side so the sample contains roughly equal representation from the top to the bottom of the chosen depth. Avoid angled scoops that collect a large amount of surface soil and very little from the bottom of the profile.

Step 3: repeat across the sampling unit

Walk a zigzag, grid, or otherwise distributed pattern that covers the whole management zone. Common university home-garden protocols use several subsamples, often roughly 8 to 15 across a modest garden area, while larger and more variable sites may use more. This is not a cannabis-specific threshold. It is a general horticultural strategy to reduce the influence of small-scale soil variability. Follow the laboratory’s own recommendation when it provides a number.

Take approximately the same amount of soil from each location. If one subsample is a heaping shovel and the other nine are narrow cores, the final mixture is weighted toward one point even though the map shows ten locations.

Field Advice: When a small bed is highly variable, adding representative subsamples is usually more useful than taking one very large scoop from the center. The laboratory analyzes only a fraction of what you send, so mixing quality matters.

Step 4: mix the subsamples thoroughly

Break apart ordinary clods, remove rocks and large roots as the laboratory instructs, and mix the subsamples in the clean bucket until the material is reasonably homogeneous. This is the point where many field locations become one composite sample. Poor mixing leaves the laboratory scoop vulnerable to whichever core happened to remain intact.

Step 5: reduce the composite to the required laboratory amount

Do not assume every laboratory wants one cup. Required volume varies by analysis. Some routine nutrient labs accept around one to two cups, while soil-health packages may require several cups. Cornell Soil Health Laboratory, for example, requires substantially more soil for its packages than for many individual tests. Check the submission instructions before discarding the extra composite.

If you need to reduce a large mixed bucket, remix it immediately before taking the final portion. For a highly heterogeneous soil with gravel or coarse organic matter, the lab may ask for extra volume. Keep enough material for a short period if the laboratory recommends retaining a backup or if you may need a confirmatory sample, but do not substitute a stored leftover for a new field sample when the real question is whether the field changed.

Pro Tip: Do not fill the sample bag from the top of an unmixed bucket after walking back to the house. Remix first. Fine particles and moisture can segregate during transport.

A repeatable field procedure

1. Confirm the laboratory method. Know the test, depth, required quantity, and handling instructions.
2. Map one sampling unit. Separate different soils, management histories, slopes, wet zones, or problem areas.
3. Use clean tools. Mark the required sampling depth and prepare a clean bucket.
4. Remove loose surface debris. Do not remove the actual soil layer you intend to test.
5. Collect equal-depth subsamples. Spread them across the sampling unit using a consistent pattern.
6. Use similar soil volume from each location. One oversized scoop should not dominate the composite.
7. Mix thoroughly. Break ordinary clods and remove non-soil debris according to lab guidance.
8. Take the laboratory-required quantity. Remix before reducing the composite.
9. Label immediately. Record sample ID, area, depth, date, and requested test.
10. Preserve and ship correctly. Air-dry, refrigerate, keep field-moist, or double-bag only as the chosen laboratory instructs.

Weedth Verdict: A good soil sample is not one perfect scoop. It is a controlled average built from several consistent subsamples taken from the right area and handled in a way that preserves the test you actually ordered.

Adjust the Method for Native Soil, Beds, Pots, and Soilless Media

The composite principle stays useful across grow systems, but the meaning of “one sampling unit” changes. Native ground is a landscape. A raised bed is a constructed soil volume. Containers are individual root zones. Coco and peat-heavy potting mixes may be laboratory substrates rather than mineral soils. Treating all four as the same material can produce a report that is difficult to interpret.

Native soil: let the landscape define the units

For an outdoor cannabis site, do not collect one core beside the stem and call it the garden. Roots extend through a volume of soil that can vary with slope, irrigation, fill history, previous crop rows, and drainage. If the planting area is relatively uniform, a distributed composite makes sense. If the soil changes from loam to clay, from upland to wet depression, or from undisturbed soil to imported fill, separate the zones.

The broader questions of outdoor soil texture, drainage, contamination history, and root-zone design belong in the main soil and outdoor guides. This resource stays focused on how to turn the chosen area into a defensible laboratory sample.

Raised beds: sample the soil you actually manage

A raised bed filled with imported soil is a distinct soil system even when it sits directly on native ground. For routine fertility testing, sample the managed bed layer according to the lab depth rather than pushing every core through the bed and into the underlying native soil. If roots are clearly using both layers and you need to understand the subsoil, submit a separate depth or native-ground sample rather than mixing the layers.

Beds that were built from different mixes or received different amendment programs should remain separate. A “raised beds” label is not enough if one bed has received years of compost and the next was filled last month.

Containers: decide whether you need an average or an individual diagnosis

If ten large outdoor containers use the same batch of soil, the same irrigation program, and the same amendment history, a composite can estimate the average root-zone chemistry of that group. But it removes plant-to-plant differences. If one pot is failing, sample it separately. If two pots are unusually vigorous, do not let them dominate the “average” simply because they are easier to access.

Collecting from an active container also means avoiding the immediate stem base and avoiding a single fertilizer pocket. Take small portions from several positions within the managed root zone when the laboratory permits container compositing, and minimize root destruction. For valuable plants, ask the laboratory how little material is required before aggressively disturbing the root ball.

Soilless media: do not force a mineral-soil test onto coco or peat

Coco, peat-based mixes, bark-heavy substrates, rockwool-associated extracts, and other soilless media can require different analytical procedures than field mineral soil. Extraction ratios and interpretation frameworks differ among laboratories. A result labeled “soil potassium” may not mean the same thing when the submitted material is mostly coco and perlite.

Tell the laboratory exactly what the medium is. If it does not test soilless substrates, use a laboratory that does. This is especially important when you are trying to interpret pH, EC, nutrient availability, or salts in a container system where irrigation and fertigation can change the root zone quickly.

Important: Do not label coco, peat-based potting mix, or another soilless substrate as ordinary garden soil just to fit a submission form. The laboratory needs the real material type to choose or interpret the correct method.

Prepare, Label, Store, and Ship the Sample Correctly

The field work is not finished when the composite enters a bag. Soil continues to change after collection. Moisture redistributes, microbes remain active, temperature can rise in a sealed bag, and soluble nitrogen forms can shift. The laboratory may intentionally dry or refrigerate the sample during processing, but your job is to deliver material in the state required by the method.

Air-dry only when the laboratory wants an air-dried sample

For many routine fertility programs, the sample is spread in a thin layer at room temperature, allowed to air-dry, then placed into the approved bag. University instructions commonly warn against oven drying. Air drying reduces shipping moisture and stabilizes many routine chemical analyses, but it is not neutral for every soil property.

If the lab asks for fresh soil, keep it cool and out of direct sun. Cornell Soil Health Laboratory instructs users to refrigerate samples after field collection and use rapid shipment, with cooling during warm weather. Those instructions exist because the package includes measurements that can respond to biological activity and sample condition.

Field Advice: Write “AIR DRY” or “KEEP COOL” on your field sheet before sampling. Handling errors are easier to prevent when the required sample condition is decided before the bags are filled.

Label the bag before the samples become confusing

Every bag needs a unique sample ID that matches the submission form. A useful home-grow label includes the area or container group, sampling depth, collection date, and a short identifier such as BED-A, NORTH-GROUND, POT-GROUP-1, or PROBLEM-POT-4. The grower can keep more detail in a notebook or spreadsheet without crowding the bag.

The form should record the test requested and enough management history to interpret the result: current use, previous crop or planting, recent lime or sulfur, fertilizer or compost applications, irrigation differences, and any specific problem being investigated. If the laboratory accepts cannabis as the crop description where cultivation is legal, use accurate information. Do not invent another crop simply to trigger an unsupported recommendation.

Keep the paperwork separate from loose soil

Follow the laboratory packaging instructions. Some laboratories want sample bags inside a sturdy shipping box and the submission form protected in a separate bag. Others provide dedicated containers. Double-bagging may be required for regulated soil or soil-health submissions. Soil movement across jurisdictions can also be regulated because soil can carry pests and pathogens. Check shipping restrictions before mailing samples across state, provincial, national, or quarantine boundaries.

Build a small chain of custody even at home

Professional laboratories use chain-of-custody systems because a correct analysis attached to the wrong sample is still a wrong result. Home growers can use a simpler version: sample ID on bag, matching ID on form, map or photo showing the sampling unit, date, depth, handling condition, and the person who collected it. If you send several samples at once, check every ID against the form before sealing the package.

Pro Tip: Photograph the labeled bags beside the completed submission form before shipping. It gives you a quick record of what actually left the garden if the laboratory later asks about an ID or depth.

Recognize the Sampling Errors That Distort Laboratory Results

Most soil-sampling mistakes do not make the laboratory instrument fail. They make the number answer the wrong question. That is why sampling error can be harder to notice than a laboratory error: the report looks professional, the units are precise, and the value may still be a faithful measurement of an unrepresentative scoop.

One scoop beside the plant is not a representative soil test

The easiest place to reach is often the least representative place to sample. Soil directly beside a stem can contain concentrated irrigation, top-dress, decomposing mulch, or disturbed transplant soil. A single scoop also provides no protection against the ordinary patchiness of garden soil. If the goal is an average condition, use a distributed composite.

Do not “improve” a sample before sending it

Do not remove fine soil because it looks muddy, add dry soil to balance a wet sample, pick out pale particles that look like perlite, or blend in compost because the original sample seems poor. Preparation means following the laboratory protocol, not making the sample look more like the soil you wish you had.

Remember: A representative sample is allowed to look disappointing. The point of testing is to measure the root zone you have, not to curate a cleaner-looking bag for the laboratory.

Recent amendments can create false confidence or false alarm

A high phosphorus or potassium result can reflect real long-term accumulation, but it can also come from sampling directly through a recent amendment patch. An unexpectedly high pH can reflect a concentrated lime particle. A high EC can reflect a fertilizer band. If the sampling history is questionable, a second cleanly collected sample is usually cheaper than rebuilding the soil around a questionable number.

Important: A laboratory soil value and a plant symptom answer different questions. Do not correct a suspected deficiency by adding more of a nutrient that the laboratory already reports as excessive until you have investigated pH, root health, salinity, moisture, and the representativeness of the sample.

A lab report from a different method may not be directly comparable

Soil laboratories can use different extractants, reporting units, calibration systems, and recommendation frameworks. Two competent laboratories can return different numerical values for the same soil because they are not performing the identical test. For trend monitoring, use the same laboratory and method when practical, or ask how to compare the methods before treating the difference as a real soil change.

Master Advice: For long-term soil tracking, consistency is part of the measurement: same sampling unit, same depth, similar season, similar field conditions, and preferably the same laboratory method.

Verify a Surprising Result Before You Rebuild the Root Zone

The purpose of a soil test is to improve decisions, not to replace observation. A report should make sense in the context of the sampling history, site behavior, irrigation, amendments, and plant performance. When the numbers fit the garden, they give you a stronger basis for planning. When the numbers look impossible, verify the sample before making an aggressive correction.

Ask whether the result is surprising biologically or only emotionally

A high nutrient level after years of compost use may be completely plausible even if the grower expected “organic” management to remain gentle. A low organic-matter value in sandy native ground may fit the soil perfectly. A high pH in calcareous soil may be difficult to change even though the grower hoped for a simple sulfur calculation. Do not re-sample only because the result is inconvenient.

Re-sample when the result conflicts with the field history, when the original sampling method was questionable, when the wrong depth was used, when the bag identity is uncertain, or when one large amendment decision depends on a value that sits far outside expectation.

Use a confirmatory sample, not the leftover bag, when field representativeness is the question

Reanalyzing the same bag can help investigate laboratory repeatability, but it does not fix a bad field sample. If the concern is that the composite did not represent the bed, return to the bed and collect a new composite using the corrected design. If the concern is an analytical error, ask the laboratory whether it can rerun the retained sample or whether a duplicate analysis is appropriate.

Weedth Verdict: When a large lime, sulfur, phosphorus, potassium, or salinity correction depends on one surprising result, re-sampling is usually a better first move than applying an irreversible amendment on faith.

Compare problem and normal zones before changing the whole garden

For a localized plant problem, a paired sample can prevent a whole-bed correction that only treats one corner. Keep the method matched between the problem and normal samples. If the soil chemistry is similar, investigate irrigation distribution, root-zone compaction, temperature, disease, pests, or plant-specific factors. If one property differs clearly, you have a stronger clue about what to investigate next.

Use repeat testing as a trend tool, not a daily feedback loop

Mineral soil chemistry does not need laboratory testing every time a leaf changes color. Routine sampling is most valuable before major amendments and at consistent intervals that match the intensity of management. Highly managed container media can change faster, but a substrate or fertigation monitoring strategy may be more appropriate than repeatedly sending a mineral-soil test.

When comparing seasons, save the old sample map, sample IDs, depths, laboratory name, and analytical method. A trend is only as strong as the consistency of the procedure behind it.

Make the Laboratory Result Represent the Soil You Actually Manage

The hardest part of laboratory soil testing is not filling the bag. It is deciding what that bag is supposed to represent. A well-designed sample keeps unlike areas separate, uses a consistent depth, spreads subsamples across the real management zone, and preserves the soil in the condition required by the laboratory. Those choices make the final numbers useful because the report can be connected back to a specific bed, site, or container group.

For cannabis, resist the urge to invent crop-specific sampling depths or universal nutrient targets that the laboratory has not validated. Use established soil-sampling principles, tell the laboratory what material you are sending, and separate routine fertility data from soil-health, substrate, salinity, or contamination questions. The strongest sample is the one another grower could collect from the same mapped area using the same method and reasonably expect to reproduce.

If the result matches the field history, use it as one part of the root-zone decision. If it does not, inspect the sampling record before adding amendments. A second representative sample can cost far less than a season spent correcting soil that was never measured correctly in the first place.