Soil Amendments Examples: 10 Types With Prices

Soil amendments are materials you mix into soil to change its pH, structure, organic matter or nutrient supply. Common soil amendments examples are agricultural lime, gypsum, elemental sulfur, poultry litter, compost, biosolids and biochar. In the week ending 9 October 2026, Alabama dealers asked an average of $59.17 a ton for lime spread on the field and $82.50 a ton for delivered poultry litter (USDA AMS Alabama Production Cost Report).

This guide lists ten amendments, what each one fixes, how they are priced, and how much a field needs. It also has a calculator that checks whether a load of manure is worth its price against bagged fertilizer. Prices below are dealer asking prices from one state report, not auction results or national averages, so treat them as a starting point and get a local quote.

Soil Amendments Examples at a Glance

The table sorts the ten materials by the problem they solve. Match the problem to a soil test first; the price only matters once you know which column you are shopping in.

Two things stand out. First, lime and sulfur are the usual materials for moving pH in a planned way; gypsum and manure do not do that job. Second, the organic materials vary a lot from load to load, so the nutrient test on the load matters as much as the price.

10 Soil Amendments Examples and What Each One Fixes

Each entry gives the job, a “Best for” line and the main caution. Rates depend on your soil test and your crop, so none of these replaces a recommendation from a lab or your local extension office.

1. Agricultural lime (calcitic limestone)

Ground limestone neutralizes soil acidity. Its strength is measured as calcium carbonate equivalent (CCE): pure calcitic limestone is 100%, and a lime with 90% CCE does only 90% of the work. Penn State Extension says that in Pennsylvania about 99% of the aglime used is ground calcitic or dolomitic limestone, and that lime should be compared on cost per unit of CCE, not cost per ton (Penn State Extension, Soil Acidity and Aglime).

Best for: fields where the soil test shows low pH and a lime requirement, such as alfalfa, clover and many grain rotations.

Watch out for: particle size. Penn State notes that lime coarser than 20 mesh reacts very slowly, and that a product with at least 95% passing 20 mesh, 60% passing 60 mesh and 50% passing 100 mesh is generally adequate.

2. Dolomitic lime

Dolomitic limestone contains magnesium as well as calcium. Penn State lists its CCE at 109%, so a ton neutralizes slightly more acid than a ton of pure calcitic lime. Because there is no official trade grade for magnesium content, the extension service advises buying on the actual magnesium analysis on the label, not the name.

Best for: acid soils that also test low in magnesium.

Watch out for: adding magnesium where the soil already has plenty. Check the soil test ratio first.

3. Gypsum (calcium sulfate)

Gypsum supplies calcium and sulfur, but it does not raise pH. Penn State is direct on this point: gypsum and Epsom salts contain calcium or magnesium, yet they are not liming materials because they cannot neutralize acidity. Growers use gypsum where they want calcium or sulfur without a pH change, and on some sodic soils as part of a reclamation plan.

Best for: calcium or sulfur needs on soils that are already at the right pH.

Watch out for: buying gypsum to fix acid soil. It will not do that job.

4. Elemental sulfur

Sulfur lowers pH. Soil bacteria oxidize it to sulfuric acid, which takes time and needs the sulfur mixed into moist soil. Oregon State University Extension describes a trial near Wilsonville, Oregon, where 45 pounds of sulfur per 1,000 square feet on a loam at pH 5.7 brought the pH to 5.1 after two years. The same guide suggests 10 to 20 pounds per 1,000 square feet on sandy soil and 40 to 50 pounds on clay soil, and warns against applying more than the recommended amount (Oregon State University Extension, EC 1560).

Best for: blueberries, rhododendrons and other acid-loving plants on soil that tests too high in pH.

Watch out for: overdoing it. Too much sulfur can drop pH so far that some elements reach toxic levels.

5. Poultry litter and other manures

Manure supplies nitrogen, phosphorus, potassium and organic matter in one load. The mix rarely matches the crop. USDA’s Economic Research Service points out that using manure to meet a crop’s nitrogen need usually applies more phosphorus than the crop needs (USDA ERS, Chart of Note, April 2023). ERS also found that manure was applied to about 8% of the 240.9 million acres planted to seven major US field crops in 2020, and, from 2013 to 2019 surveys of growers who used manure, that corn received the highest manure nitrogen rate, 92 pounds per acre.

Nutrient content varies. Virginia Tech’s agronomy handbook lists dry broiler litter tested in Virginia (October 2001 to October 2004) at an average of 64.9 pounds of total nitrogen, 52.2 pounds of phosphate and 53.4 pounds of potash per ton, with 27.8% moisture (Virginia Tech, Agronomy Handbook Part XI). Semi-solid dairy manure in the same table had only 15.3 pounds of nitrogen per ton.

Best for: fields within short hauling distance of poultry or livestock farms, where the soil also needs phosphorus and potassium.

Watch out for: building up phosphorus. Test the manure and the soil, and follow your state nutrient management rules.

6. Compost

Compost adds stable organic matter, improves structure and releases nutrients slowly. The US EPA describes composting as a way to cut landfill waste and build healthy soil, and notes that only 5% of the 66.2 million tons of wasted food from retail, food service and homes in 2019 was composted (US EPA, Composting).

Best for: vegetable beds, orchards and degraded or low-organic-matter soils.

Watch out for: unknown sources. Oregon State University Extension advises asking whether compost has been tested for metals, and notes that products with the US Composting Council Seal of Testing Assurance or the OMRI logo have been tested (Oregon State University Extension, EC 1616).

7. Biosolids

Biosolids are treated sewage sludge that meets federal rules for land application. They add organic matter, nitrogen and phosphorus. Farmers usually get them through a utility or a contracted hauler rather than at a posted retail price. Land application is regulated, and your state or the EPA sets site, crop and waiting-period rules.

Best for: large field programs near a city treatment plant, where a permitted program is in place.

Watch out for: buyer contracts and local rules. Some food buyers and some states restrict biosolids, so check before you sign.

8. Biochar

Biochar is charcoal made for soil use. It can help sandy or degraded soils hold water and nutrients. Results vary with the feedstock, the soil and the rate, and field-scale prices are not tracked in a public federal price series.

Best for: small, high-value areas and trials on poor sandy soils.

Watch out for: paying for a large area before a strip trial shows a response on your soil.

9. Cover crops and green manure

A cover crop grown and then worked in or left as residue is a living amendment. Legumes add nitrogen, grasses add root mass, and both protect the surface from erosion. The cost is seed and planting rather than a delivered material.

Best for: rotations with a gap between cash crops.

Watch out for: timing. A cover crop that is not ended on time can use water the next crop needs.

10. Polymers, gels and other stabilizers

Stabilizers such as polyacrylamide (PAM) are used mainly to keep soil in place on furrows, ditches and slopes, not to add nutrients. They are priced per pound of product and applied at low rates.

Best for: furrow irrigation and erosion-prone beds.

Watch out for: product labels and local rules, which set rates and where the product may be used.

▶ How mixed farms use manure from their own livestock as fertilizer, explained in under three minutes. · 2:55

Soil Amendment Prices per Ton

USDA’s Agricultural Marketing Service publishes a weekly Alabama Production Cost Report with dealer asking prices for lime, poultry litter and synthetic fertilizer. For the week ending 9 October 2026, lime averaged $59.17 a ton delivered and applied, within a range of $40 to $75. Poultry litter averaged $20 a ton picked up at the farm (range $15 to $25) and $82.50 a ton delivered (range $65 to $100). These are asking prices from distributors in one state, not transaction prices and not a national average.

Chart

Average asking price per ton, Alabama

US$ per ton, distributor asking prices, week ending 9 October 2026; lime delivered and applied, fertilizers picked up

For comparison, the same report listed urea (46-0-0) at an average of $778.40 a ton, DAP (18-46-0) at $961.83 and red potash (0-0-60) at $535.20, all picked up at the dealer. A ton of litter costs far less than a ton of urea, but it also carries far fewer pounds of nutrients, so price per ton alone is a poor guide. The calculator below converts both to value per pound of nutrient.

Freight is the main story in the litter prices. Delivered litter averaged about four times the picked-up price, so the same material costs very different amounts on farms near and far from poultry houses. Lime is similar: it is heavy, cheap at the quarry and expensive to haul.

Compost and biochar have no comparable public weekly price series. For those, ask two or three local suppliers for a delivered quote with a lab analysis, and compare them on organic matter and nutrient content per ton of dry material.

The AMS report is updated weekly at the link above, so check the newest edition before you budget. Other states publish similar reports through USDA Market News.

Chart

Low and high asking prices per ton, Alabama

US$ per ton, range of distributor asks, week ending 9 October 2026

Is Manure Worth Its Price? Nutrient Value Calculator

This tool compares what you pay for a ton of manure or litter with what the same nutrients would cost as bagged fertilizer. Enter your own manure test, your delivered price and your local fertilizer prices. A positive result means the nutrients are worth more than the manure costs, but only if your soil test says the crop needs all three nutrients.

To turn fertilizer prices into a price per pound of nutrient, divide the price per ton by the pounds of nutrient in a ton. Urea is 46% nitrogen, so a ton holds 920 pounds of N. Potash is 60% K2O, so a ton holds 1,200 pounds. For phosphate from DAP, subtract the value of its 360 pounds of nitrogen before dividing by its 920 pounds of P2O5. With the Alabama prices above, that gives about $0.85 per pound of N, $0.71 per pound of P2O5 and $0.45 per pound of K2O.

Not all the nitrogen in manure is available to the crop in the first year. The University of Kentucky notes that availability depends mostly on the timing of application and whether the manure is mixed into the soil, so enter plant-available nitrogen from your lab report or your state’s tables, not total nitrogen (University of Kentucky, AGR-146).

Try the numbers for your own farm below.

How to Choose a Soil Amendment in 6 Steps

1. Test the soil. A lab test gives pH, the lime requirement (buffer pH), phosphorus, potassium and organic matter. Without it you are guessing.
2. Name the problem. Low pH calls for lime. High pH for acid-loving crops calls for sulfur. Low organic matter calls for compost, manure or cover crops. Calcium or sulfur needs at a good pH may call for gypsum.
3. Test the material. Ask for the CCE and fineness of lime, and a nutrient and moisture analysis of manure or compost.
4. Compare on the unit that matters. Compare lime on cost per ton of CCE, and manure on cost per pound of available nutrient, not cost per ton.
5. Add freight and spreading. A cheap material far away can cost more in the field than a pricier one nearby.
6. Check the result. Re-test soil after one or two seasons and compare crop growth across treated and untreated strips.

Clemson University’s Home and Garden Information Center notes that soils low in clay need less lime to reach the same pH change as soils high in clay, and that the soil test and the plant’s preferred pH range should decide how much lime to use (Clemson HGIC, Changing the pH of Your Soil). That is why two fields with the same pH can need very different lime rates.

Fertilizer, manure and biosolids rules vary by state and country. Check the product label, your local rules and, for large programs, get advice from a certified crop adviser or your extension office.

How Much Soil Amendment to Apply: Sizing the Job

Sizing means turning a lab recommendation into tons of a real product for a real field.

Lime

Lab lime recommendations are usually given as pounds or tons of CCE per acre. Penn State explains that the actual amount of product depends on its CCE, its moisture and the depth you mix it to. A simple check: divide the recommended tons of CCE by the product’s CCE as a decimal. If a lab asks for 2 tons of CCE and your lime is 90% CCE, you need about 2.2 tons of product, plus more if the lime is wet. Penn State also suggests adjusting the rate once moisture reaches about 10%.

For no-till fields, Penn State recommends checking the top 2 inches separately. If surface pH is below 6.2 and the standard sample shows no lime need, it suggests 2,000 pounds of CCE per acre to treat the surface layer.

Sulfur

Sulfur rates are smaller and are often given per 1,000 square feet for gardens and small plantings. Use the Oregon State ranges above as a guide only, and re-test before adding more.

Manure and litter

The University of Kentucky’s worked example for no-till corn needing 180 pounds of nitrogen found that 6.9 tons of broiler litter per acre could supply all the nitrogen. But that rate would also add about 234 pounds of excess phosphate and 185 pounds of excess potash per acre. Rates based on phosphorus need, topped up with bagged nitrogen, keep soil phosphorus from building up.

Compost

For gardens and small plots, Oregon State University Extension recommends 1 to 2 inches of composted yard debris each year on beds where lead-contaminated dust is a concern, and warns that high-nitrogen manures can carry soluble salts that injure plants if over-applied.

Biosolids and Compost: Supply and Safety

Biosolids are a large source of organic amendment in the US. Based on reports filed in 2024 by about 2,350 facilities, the EPA estimates that about 4 million dry metric tons of sewage sludge were generated, and about 2.39 million dry metric tons were land applied (US EPA, Basic Information about Biosolids). The rest was mainly landfilled or incinerated. Nine states run their own biosolids programs and are not in these totals.

Chart

What happened to US sewage sludge

Million dry metric tons, EPA estimates from Biosolids Annual Reports filed in 2024 (excludes nine state-run programs)

Land-applied biosolids can go to farms, mine reclamation, forestry or retail products sold for lawns and gardens. The EPA notes that one load can fit more than one end use, so the categories overlap.

For any organic material, ask for a recent lab analysis covering nutrients, moisture, salts and metals. Material sold to the public as compost may carry a testing seal, and biosolids programs keep records of what was applied where. Keep your own records too: field, date, rate and source. They help with nutrient plans, buyer audits and comparing results later.

Amendments for Hydroponic and Container Growers

Hydroponic systems grow plants in rockwool, coconut coir, perlite or clay pebbles, with nutrients in the water. There is no soil to amend in the field sense. When growers talk about hydroponic amendments, they usually mean one of three things:

• buffering agents that condition coir before planting;
• additives in the substrate, such as biochar mixed into coir, or root inoculants;
• soil-based container mixes that are fed with hydroponic-style fertigation.

USDA market reports do not track these products. They are sold through greenhouse and garden supply channels, so a distributor quote is the best price source. For container growers, OSU’s advice on buying tested compost and planting mix applies here too.

Soil Biology: Why Amendments Feed the Soil Food Web

Organic amendments do more than add nutrients. Compost, manure and residues feed earthworms, fungi, bacteria and small soil animals that break down organic matter and release nutrients. Mineral amendments such as lime change soil chemistry, which can help biology by bringing pH into a better range, but they add little food for soil organisms.

There is a trade-off. Fresh, undecomposed organic matter can favour some soil pests, such as wireworms, root maggots or white grubs in some fields. Integrated pest management pairs amendment plans with scouting rather than treating more organic matter as always better. If pests are a concern, our guide to natural pest control options covers non-chemical steps.

▶ Why soil organic matter matters for crops and the soil food web. · 7:33

Soil Stabilizing Agents vs Amendments

Stabilizing agents and amendments overlap but are budgeted differently. Lime or manure corrects pH or nutrients, with a cost per ton and a clear rate from a soil test. A stabilizer is bought to hold soil structure or reduce erosion and may need reapplying on a different schedule.

• Polyacrylamide granules: used in irrigation water and on furrows and ditch banks to reduce soil loss.
• Biochar blends: used to improve water and nutrient holding in sandy or degraded soils; carbon storage is a side benefit claimed for some products.
• Algal and plant-based gels: used in some organic systems to help soil form crumbs (aggregates).

If erosion is the main problem, cover crops, residue and field layout usually come before any purchased stabilizer.

Example: Amending Soil for Bell Peppers

Bell peppers show why the amendment has to fit the crop as well as the soil. Clemson Extension advises keeping pepper soil at pH 6.0 to 6.5, guided by a soil test. Peppers are prone to blossom-end rot, a calcium disorder in the fruit. Clemson notes it does not always mean the soil is short of calcium: an uneven water supply stops calcium reaching the fruit, so it advises keeping soil evenly moist. A grower who adds lime to fix blossom-end rot without testing pH first can push pH above the crop’s best range and still have the problem.

A sensible plan for peppers:

• test pH and nutrients before planting;
• use lime only if pH is low; use gypsum if calcium is low but pH is fine;
• add compost or aged manure for organic matter, avoiding fresh, salty manure near transplanting;
• keep watering even, with drip and mulch, to reduce blossom-end rot;
• plan nitrogen with a budget, as in our nitrogen management tips.

Testing Before You Spend: Soil Testers and Field Maps

Buying an amendment before testing is the easiest way to overspend. A lab test gives lime requirement and nutrient levels that a handheld probe cannot. Handheld meters are useful for quick pH or moisture checks, but readings vary with probe quality and soil moisture, so use them to decide where to sample, not what to apply.

Fields are rarely uniform. Satellite crop maps can show where growth lags across a field, which helps you choose where to pull extra soil samples. Farmonaut provides this kind of field mapping, and like any satellite tool it shows where plants differ, not the cause, so the soil test still decides the amendment.

▶ What a satellite moisture map shows across a field, and where a soil probe still wins. · 2:11

How We Checked the Numbers

Prices come from the USDA AMS Alabama Production Cost Report for the week ending 9 October 2026. They are distributor asking prices, with the freight basis shown (picked up or delivered). Manure nutrient figures come from Virginia Tech’s handbook table and the University of Kentucky’s worked example; manure use and rates come from USDA ERS. Lime quality figures come from Penn State Extension; sulfur rates from Oregon State University Extension; biosolids volumes from the EPA’s 2024 annual reports. We did not use private market-size estimates, because no public agency publishes a dollar figure for the whole soil amendment market that we could check.

For a closer look at a related question, see our guide: Corn Futures Prices Prediction & Trading Trends.

FAQ

What are some soil amendments examples?

Common examples are agricultural lime, dolomitic lime, gypsum, elemental sulfur, poultry litter and other manures, compost, biosolids, biochar, cover crops and erosion-control polymers. Lime raises pH, sulfur lowers it, and the organic materials add organic matter and nutrients.

What do soil amendments cost?

In Alabama, for the week ending 9 October 2026, dealers asked an average of $59.17 a ton for lime delivered and applied, $20 a ton for poultry litter picked up and $82.50 a ton delivered (USDA AMS). Compost and biochar prices vary by supplier and are not tracked in a public weekly report.

Is gypsum the same as lime?

No. Both add calcium, but only lime neutralizes acidity. Penn State Extension states that gypsum is not a liming material and will not raise soil pH.

Is manure cheaper than synthetic fertilizer?

Per ton, yes; per pound of nutrient, it depends. Litter has far fewer pounds of nutrients per ton than urea or DAP, and only part of its nitrogen is available in the first year. Use the calculator with your manure test and local prices.

How big is the organic soil amendment market?

No US agency publishes a single dollar figure for it. Public data tracks volumes instead: the EPA estimates about 2.39 million dry metric tons of biosolids were land applied in reports filed in 2024, and USDA ERS found manure on about 8% of acres planted to seven major field crops in 2020.

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